Co-reporter:Jinming Zhang, Nan Luo, Jiqiang Wan, Guangmei Xia, Jian Yu, Jiasong He, and Jun Zhang
ACS Sustainable Chemistry & Engineering June 5, 2017 Volume 5(Issue 6) pp:5127-5127
Publication Date(Web):April 25, 2017
DOI:10.1021/acssuschemeng.7b00488
It is attractive and meaningful to effectively utilize agricultural straws for preparing high value-added materials. In this work, we employ corn husk as a model substance for agricultural straws. By using microcrystalline cellulose (MCC) as an adhesive and reinforcing phase, direct utilization of corn husk is achieved, and consequently, corn husk/MCC films are fabricated in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). Corn husk is dissolved completely in AmimCl; then, MCC is added and partially dissolved by controlling the dissolution conditions. The undissolved nanocrystals from MCC are used as the reinforcing phase, and the dissolved MCC is used as the adhesive and part of the matrix. As a result, homogeneous, transparent, beige-colored corn husk/MCC nanocomposite films are obtained. The resultant nanocomposite films with the content of corn husk in a range of 50–71 wt % exhibit high tensile properties. The tensile strength and elastic modulus of nanocomposite films containing 50 wt % corn husk have reached 67 MPa and 4.4 GPa, respectively. Thus, this work provides a simple, economical, and effective method for converting sustainable biomass resources into valuable materials.Keywords: Agricultural straw; All-biomass materials; Cellulose nanocrystals; Corn husk; Self-reinforced nanocomposite;
Co-reporter:Jinming Zhang;Jin Wu;Jian Yu;Xiaoyu Zhang;Jiasong He
Materials Chemistry Frontiers 2017 vol. 1(Issue 7) pp:1273-1290
Publication Date(Web):2017/06/28
DOI:10.1039/C6QM00348F
Cellulose, a well-known fascinating biopolymer, has been considered to be a sustainable feedstock of energy sources and chemical engineering in the future. However, due to its highly ordered structure and strong hydrogen bonding network, cellulose is neither meltable nor soluble in conventional solvents, which limits the extent of its application. Therefore, the search for powerful and eco-friendly solvents for cellulose processing has been a key issue in this field for decades. More recently, certain ionic liquids (ILs) have been found to be able to efficiently dissolve cellulose, providing a new and versatile platform for cellulose processing and functionalization. A series of cellulose-based materials, such as films, fibers, gels and composites, have been produced readily with the aid of ILs. This review article highlights recent advances in the field of dissolution and processing of cellulose with ILs. It is hoped that this review work will stimulate a wide range of research studies and collaborations, leading to significant progress in this area.
Co-reporter:Jinming Zhang, Nan Luo, Xiaoyu Zhang, Lili Xu, Jin Wu, Jian Yu, Jiasong He, and Jun Zhang
ACS Sustainable Chemistry & Engineering 2016 Volume 4(Issue 8) pp:4417
Publication Date(Web):June 16, 2016
DOI:10.1021/acssuschemeng.6b01034
All-cellulose nanocomposites, with cellulose nanocrystals as the reinforcing phase and regenerated cellulose as the matrix, are prepared by a partial dissolution method in 1-ally-3-methylimidazolium chloride (AmimCl), followed by solution casting. The direct images of many undissolved nanocrystals in cellulose/AmimCl solutions have been observed clearly by conventional transmission electron microscopy (TEM). X-ray diffraction (XRD) also proves that there are original cellulose I crystals in regenerated cellulose films. The nanocomposite films are compact, isotropic and transparent to visible light, and show good mechanical properties as a result of the nanocrystals reinforcement. Using microcrystalline cellulose (MCC) as the raw material, the optimal tensile strength and elastic modulus of nanocomposite films have reached 135 MPa and 8.1 GPa, respectively, by controlling the dissolution temperature and time. This work provides an easy and effective pathway to prepare all-cellulose composites.Keywords: All-cellulose composite; Cellulose nanocrystal; Ionic liquid; Nanocomposite; Self-reinforcing materials
Co-reporter:Qin-yong Mi, Shu-rong Ma, Jian Yu, Jia-song He, and Jun Zhang
ACS Sustainable Chemistry & Engineering 2016 Volume 4(Issue 3) pp:656
Publication Date(Web):January 15, 2016
DOI:10.1021/acssuschemeng.5b01079
Monolithic cellulose aerogels were prepared via a dissolution–regeneration route by dissolving cellulose in 1-allyl-3-methylimidazolium chloride (AMIMCl). Using a high concentration aqueous AMIMCl solution as the regeneration bath endowed cellulose aerogels with high flexibility and transparency. Possessing homogeneous nanoscale porous morphology, the strong cellulose aerogels have excellent compressive properties, low densities, and low thermal conductivities.Keywords: Aerogels; Cellulose; Flexible; Ionic liquid; Nanoporous; Transparent
Co-reporter:Guangmei Xia, Jiqiang Wan, Jinming Zhang, Xiaoyu Zhang, Lili Xu, Jin Wu, Jiasong He, Jun Zhang
Carbohydrate Polymers 2016 Volume 151() pp:223-229
Publication Date(Web):20 October 2016
DOI:10.1016/j.carbpol.2016.05.080
•Waste newspapers after simple pretreatment could be quickly dissolved in AmimCl.•The cellulose of waste newspapers degraded lightly in the dissolving process.•The regenerated films retain almost all of the ingredients in waste newspapers.•The regenerated cellulose-based films exhibited good mechanical property.Waste newspapers, composed of cellulose (>60 wt%), lignin (∼15 wt%), hemicellulose (∼10 wt%) and other additives, are one kind of low-cost, easily collected and abundant resources. In order to get value-added products from this waste, in this work an attempt was made to directly convert waste newspapers into cellulose-based films by employing an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as a solvent. Most of the organic substances in this waste were dissolved quickly in AmimCl under mild conditions, and then coagulated and dried. Although containing lignin, hemicellulose and inorganic additives, the regenerated cellulose-based films were smooth, compact and semi-transparent, and exhibited good mechanical properties. If the newspaper/AmimCl solution was filtered to remove undissolved inorganic substances, the regenerated films became transparent and had a tensile strength of 80 MPa. Thus, this work provides a new, simple and highly efficient way to achieve a high-valued utilization of waste newspapers for packaging and wrapping.
Co-reporter:Ye Feng, Jinming Zhang, Jiasong He, Jun Zhang
Carbohydrate Polymers 2016 Volume 147() pp:171-177
Publication Date(Web):20 August 2016
DOI:10.1016/j.carbpol.2016.04.003
•The dispersion of eight kinds of POSS derivatives in ionic liquid is probed.•Transparent cellulose/POSS-AN nanocomposites are prepared.•POSS-AN nanoparticles are uniformly dispersed in cellulose at nanoscale.•The nanocomposites exhibit excellent anti-UV aging and UV shielding properties.The solubility of eight types of polyhedral oligomeric silsesquioxane (POSS) derivatives in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) and the dispersion of POSS in cellulose matrix were examined. Only a special POSS containing both aminophenyl and nitrophenyl groups (POSS-AN, NH2:NO2 = 2:6) was selected to prepare nanocomposites, because of its good solubility in AmimCl and high stability during the preparation process. POSS-AN nanoparticles were uniformly dispersed in a cellulose matrix with a size of 30–40 nm, and so the resultant cellulose/POSS-AN nanocomposite films were transparent. The mechanical properties of the films achieved a maximum tensile strength of 190 MPa after addition of 2 wt% POSS-AN. Interestingly, all of the cellulose/POSS-AN films exhibited high UV-absorbing capability. For the 15 wt% cellulose/POSS-AN film, the transmittance of UVA (315–400 nm) and UVB (280–315 nm) was only 9.1% and nearly 0, respectively. The UV aging and shielding experiments showed that the transparent cellulose/POSS-AN nanocomposite films possessed anti-UV aging and UV shielding properties.
Co-reporter:Jiajian Liu;Jinming Zhang;Baoqing Zhang;Xiaoyu Zhang;Lili Xu
Cellulose 2016 Volume 23( Issue 4) pp:2341-2348
Publication Date(Web):2016 August
DOI:10.1007/s10570-016-0967-1
For simply and accurately determining molecular weight of cellulose, an ionic liquid mixed with a co-solvent, 1-butyl-3-methylimidazolium acetate/dimethyl sulfoxide (BmimAc/DMSO) (1:1, w/w) was used and dissolved cellulose well at ambient temperature. During the dissolution process no degradation of cellulose was observed, and all the resultant cellulose/BmimAc/DMSO solutions were transparent and stable. These advantages make it as an ideal solvent system to build a new characteristic method of cellulose’s molecular weight by the measurement of the intrinsic viscosity [η], which is significantly better than the currently used solvent systems. [η] of solutions of nine cellulose samples was measured by using rheometer with cylinder fixture and Ubbelohde viscometer, respectively. The [η] values obtained by these two methods were well consistent. The degree of polymerization (DP) of these cellulose samples was determined by Copper (II) ethylenediamine method. Then the molecular weight and its distribution of representative samples were cross-checked by gel permeation chromatography for soluble derivatives of cellulose. As a result, a relationship DP = 134 [η]1.2 was built, suitable for DPs in the range of 220–1400. The uncertainty of this relationship was estimated to be 5 %. This work provided a simple, accurate and reliable method for determining [η] and the molecular weight of cellulose.
Co-reporter:Bin Yuan;Jinming Zhang;Jian Yu;Rui Song;Qinyong Mi
Science China Chemistry 2016 Volume 59( Issue 10) pp:1335-1341
Publication Date(Web):2016 October
DOI:10.1007/s11426-016-0188-0
Cellulose-based nanocomposite aerogels were prepared by incorporation of aluminum hydroxide (AH) nanoparticles into cellulose gels via in-situ sol-gel synthesis and following supercritical CO2 drying. The structure and properties of cellulose/AH nanocomposite aerogels were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, ultraviolet-visible spectrometry, N2 adsorption, thermogravimetric analysis, and micro-scale combustion calorimetry. The results indicated that the AH nanoparticles were homogeneously distributed within matrix, and the presence of AH nanoparticles did not affect the homogeneous nanoporous structure and morphology of regenerated cellulose aerogels prepared from 1-allyl-3-methylimidazolium chloride solution. The resultant nanocomposite aerogels exhibited good transparency and excellent mechanical properties. Moreover, the incorporation of AH was found to significantly decrease the flammability of cellulose aerogels. Therefore, this work provides a facile method to prepare transparent and flame retardant cellulose-based nanocomposite aerogels, which may have great potential in the application of building materials.
Co-reporter:Jinming Zhang;Lili Xu;Jian Yu;Jin Wu;Xiaoyu Zhang
Science China Chemistry 2016 Volume 59( Issue 11) pp:1421-1429
Publication Date(Web):2016 November
DOI:10.1007/s11426-016-0269-5
The effect of ionic liquids (ILs) on the solubility of cellulose was investigated by changing their anions and cations. The structural variation included 11 kinds of cations in combination with 4 kinds of anions. The interaction between the IL and cellobiose, the repeating unit of cellulose, was clarified through nuclear magnetic resonance (NMR) spectroscopy. The reason for different dissolving capabilities of various ILs was revealed. The hydrogen bonding interaction between the IL and hydroxyl was the major force for cellulose dissolution. Both the anion and cation in the IL formed hydrogen bonds with cellulose. Anions associated with hydrogen atoms of hydroxyls, and cations favored the formation of hydrogen bonds with oxygen atoms of hydroxyls by utilizing activated protons in imidazolium ring. Weakening of either the hydrogen bonding interaction between the anion and cellulose, or that between the cation and cellulose, or both, decreases the capability of ILs to dissolve cellulose.
Co-reporter:Fuyong Liu, Yuxia Lv, Jiajian Liu, Zhi-Chao Yan, Baoqing Zhang, Jun Zhang, Jiasong He, and Chen-Yang Liu
Macromolecules 2016 Volume 49(Issue 16) pp:6106-6115
Publication Date(Web):August 2, 2016
DOI:10.1021/acs.macromol.6b01171
Polymer and ionic liquid (IL) mixtures have attracted an increasing amount of attention due to their unique properties and potential applications. The interactions between poly(ethylene oxide) (PEO) and imidazolium ILs of different cation alkyl lengths and anion structures have been investigated by measuring melting points (Tm), contact angles, and rheological properties. Tm of crystalline PEO dramatically decreased when it was blended with ILs. Similarly, the contact angles of different ILs on a PEO surface proportionally decreased. The interaction energy, as calculated from melting point depression using the Flory equation, increased with the length of imidazolium alkyl cations and the size of anions. The different anionic structures had a more significant influence on the interaction energy than the alkyl chain lengths of cations. These trends accorded with the solubility obtained by high-energy X-ray diffraction and swelling ratio measurements of PEO in different ILs [Asai Macromolecules 2013, 46, 2369−2375] and the solubility of poly(methyl methacrylate) in different ILs [Ueno Langmuir 2014, 30, 3228−3235]. The rheological behavior of PEO in three different anionic ILs has also been studied to determine the effect of the anions on PEO conformations. The molecular weight dependence of the intrinsic viscosity of PEO in ILs revealed that the solvent quality of ILs (from poor solvents to good solvents) is highly influenced by anionic structures, which was consistent with the results of the melting point depression and contact angle.
Co-reporter:Meichun Ding, Jian Yu, Jiasong He and Jun Zhang
RSC Advances 2015 vol. 5(Issue 55) pp:44648-44651
Publication Date(Web):08 May 2015
DOI:10.1039/C5RA06740E
An unusual spherulite morphology consisting of an eye-like region surrounded by a normal region was found in concentrated cellulose solutions in the ionic liquid AmimCl, especially in the presence of 0.5 wt% MWCNTs. In comparison with the normal region, the eye-like region had a different growth rate and different morphology, such as birefringence and band spacing, although both regions had similar crystalline modification and microstructure. On heating, the regions with an initial positive birefringence transformed to more thermodynamically stable negative ones without influencing the band spacing, and the change was irreversible upon cooling.
Co-reporter:Chenghu Yan, Jin Wu, Jinming Zhang, Jiasong He, Jun Zhang
Polymer Degradation and Stability 2015 Volume 118() pp:130-136
Publication Date(Web):August 2015
DOI:10.1016/j.polymdegradstab.2015.04.019
A series of cellulose-g-poly(l-lactide) (cellulose-g-PLLA) copolymers with 30.65–85.21 % PLLA weight content and the molar substitution of PLLA (MSPLLA) from 0.99 to 12.73 were synthesized via the homogeneous graft-from reaction in 1-allyl-3-methylimidazolium chloride (AmimCl) with 4-dimethylaminopyridine (DMAP) acting as the catalyst. In common organic solvents, the solubility of obtained graft copolymers was better than cellulose and strongly depended on the MSPLLA. The hydrolytic degradation of cellulose-g-PLLA copolymers was investigated in phosphate buffered solution (PBS, pH 7.4) at 37 °C. Interestingly, it was found that, when the MSPLLA was below 8.83, the hydrolytic degradation rate of cellulose-g-PLLA copolymers was obviously faster than that of both pristine cellulose and PLLA. Moreover, as the MSPLLA decreased, the cellulose-g-PLLA copolymers showed a more rapid weight loss, due to its higher hydrophilicity. Both XPS and 1H NMR analyses demonstrated the degradation occurred mainly at PLLA segments. The morphological observations indicated that, during the hydrolytic degradation, the graft copolymers firstly experienced a surface erosion process, and then the bulk erosion happened.
Co-reporter:Weiwei Chen, Ye Feng, Mei Zhang, Jin Wu, Jinming Zhang, Xia Gao, Jiasong He and Jun Zhang
RSC Advances 2015 vol. 5(Issue 72) pp:58536-58542
Publication Date(Web):30 Jun 2015
DOI:10.1039/C5RA08911E
Homogeneous benzoylation of cellulose with a series of substituted benzoyl chlorides, in which substituents varied from electron donating to electron withdrawing groups, was investigated in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). The electronic effect of substituents had a considerable effect on the reaction. A plot of Hammett parameters of substituents vs. degree of substitution (DS) of resultant cellulose esters exhibited a V-shaped graph: a negative slope for negative Hammett parameters, and a positive slope for positive Hammett parameters. Such a Hammett plot indicated the mechanism of cellulose benzoylation: the reaction underwent a unimolecular ionization mechanism with a carbocationic intermediate when benzoyl chlorides were with electron-donating substituents, and a bimolecular addition–elimination mechanism with a tetrahedral intermediate when benzoyl chlorides were with electron-withdrawing substituents. In addition, 13C-NMR analysis showed that most of the substituted benzoyl chlorides exclusively preferred the primary hydroxyl at the C-6 position. This unusually high regioselectivity was attributed to the synergistic effect of appropriate reaction rate, moderate steric effect and reaction mechanism of benzoylation.
Co-reporter:Jinming Zhang;Weiwei Chen;Ye Feng;Jin Wu;Jian Yu;Jiasong He
Polymer International 2015 Volume 64( Issue 8) pp:963-970
Publication Date(Web):
DOI:10.1002/pi.4883
Abstract
Homogeneous esterification of cellulose, which can control the molecular structure of the resultant cellulose esters and facilitate the versatility of cellulose-based materials, has drawn much attention. Recently, the advent of room temperature ionic liquids (ILs) capable of dissolving cellulose has provided a new and versatile platform for the efficient and homogeneous esterification of cellulose. A variety of conventional, novel and functional cellulose esters have been successfully synthesized in ILs. Meanwhile, development of esterification techniques, utilization of agricultural residues and up-scaling of pilot schemes of esterification in ILs have been in progress. This review summarizes the advances and developments in homogeneous synthesis of cellulose esters in ILs in recent decades. © 2015 Society of Chemical Industry
Co-reporter:Weiwei Chen;Mei Zhang;Ye Feng;Jin Wu;Xia Gao;Jinming Zhang;Jiasong He
Polymer International 2015 Volume 64( Issue 8) pp:1037-1044
Publication Date(Web):
DOI:10.1002/pi.4884
Abstract
Homogeneous carbanilation of cellulose with nine kinds of substituted phenyl isocyanates, in which the substituents were varied from electron-donating to electron-withdrawing groups, was carried out in 1-allyl-3-methylimidazolium chloride (AmimCl) without any catalyst. The degree of substitution (DS) of cellulose phenylcarbamates in a range from 0 to 3 was readily controlled by altering reaction temperature, reaction time and molar ratio of phenyl isocyanate/anhydroglucose unit. Furthermore, the electronic effect of the substituents on the aromatic ring had a prominent impact on the reactivity of phenyl isocyanates. The phenyl isocyanates with stronger electron-withdrawing substituents exhibited a higher reactivity. A plot of DS and Hammett substituent constants exhibited linearity with a positive slope. Subsequently, four kinds of partially substituted cellulose phenylcarbamates with DS of 2.0 were synthesized successfully in AmimCl, and then employed as coated-type chiral stationary phases (CSPs) for high-performance liquid chromatography. The enantioseparation results demonstrated that these CSPs exhibited high chiral recognition abilities for some racemates. The substituents on the phenyl moieties had a considerable effect on the chiral recognition ability of cellulose phenylcarbamate-based CSPs. © 2015 Society of Chemical Industry
Co-reporter:Lili Yang;Jinming Zhang;Jiasong He;Zhihua Gan
Polymer International 2015 Volume 64( Issue 8) pp:1045-1052
Publication Date(Web):
DOI:10.1002/pi.4912
Abstract
The homogeneous preparation of amino-reserved chitosan-graft-polycaprolactone copolymer (ACS-g-PCL) was achieved in 1-butyl-3-methylimidazolium acetate via a protection − ring-opening graft polymerization − deprotection procedure. The molar substitution of PCL (MSPCL) in ACS-g-PCL copolymers was in the range 17.1 − 45.6 and could be well controlled by altering reaction conditions. The resultant ACS-g-PCL copolymers were soluble in some common organic solvents such as dimethylsulfoxide, ethanol and toluene. As the increment of MSPCL increased, the hydrophilicity of the ACS-g-PCL copolymers decreased. Eventually, ACS-g-PCL microspheres with a diameter of 100–200 µm were fabricated by an emulsion evaporation method. Among them, the ACS-g-PCL copolymer with an MSPCL of 26.8 formed into porous microspheres. The fluorescence microscopy and cytotoxicity results suggested that all of the microspheres, especially the ACS-g-PCL microspheres with MSPCL of 17.1 and 26.8, showed high cell adhesion and cytocompatibility to the human osteosarcoma cell line (MG-63), indicating their great prospects in tissue engineering. © 2015 Society of Chemical Industry
Co-reporter:Li-li Yang;Jin-ming Zhang;Jia-song He 张军
Chinese Journal of Polymer Science 2015 Volume 33( Issue 12) pp:1640-1649
Publication Date(Web):2015 December
DOI:10.1007/s10118-015-1703-2
A new series of cellulose-graft-poly(N-isopropylacrylamide) (cellulose-g-PNIPAM) copolymers were prepared by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide monomers from a cellulose-based macro-initiator, which was homogeneously synthesized in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). The composition of cellulose-g-PNIPAM copolymers could be adjusted by altering the feeding ratio and reaction time. The resultant copolymers with relatively high content of PNIPAM segments (molar substitution of PNIPAM ≥ 18.3) were soluble in water at room temperature. Aqueous solutions of cellulose-g-PNIPAM copolymers exhibited clear temperature-sensitive behavior, and their sol-to-gel phase transition properties were investigated by dynamic light scattering (DLS) and UV measurements. Compared with pure PNIPAM, the cellulose-g-PNIPAM copolymers possessed higher lower critical solution temperatures (LCST) in a range from 36.9 °C to 40.8 °C, which are close to normal human body temperature, and could be tuned by adjusting the content of PNIPAM segments in copolymers. Spherical structure of cellulose-g-PNIPAM copolymers formed at temperatures above LCST and its morphology was observed by TEM and SEM. These novel cellulose-g-PNIPAM copolymers may be attractive substrates for some biomedical applications, such as drug release and tissue engineering.
Co-reporter:Wei-wei Chen;Mei-chun Ding;Mei Zhang
Chinese Journal of Polymer Science 2015 Volume 33( Issue 12) pp:1633-1639
Publication Date(Web):2015 December
DOI:10.1007/s10118-015-1695-y
A series of cellulose 3,5-dimethylphenylcarbamates (CDMPCs) with different degrees of substitution (DS) and degrees of polymerization (DP) were homogeneously synthesized in 1-allyl-3-methylimidazolium chloride (AmimCl). Then, the CDMPCs were coated on silica gel and used as chiral stationary phases (CSPs), and their chiral recognition abilities for seven racemates were evaluated by high performance liquid chromatography. The results showed that DS and DP of CDMPCs had a great influence on chiral recognition abilities of the CSPs. The CSPs with the DS ≈ 1 gives a low chiral recognition to most racemates. On the contrast, the CSPs with the DS ≥ 2 exhibited high chiral separation abilities. For example, six racemates could be separated on the CSP with CDMPC of DS ≈ 2 (CSP-2). Especially, for the enantioseparation of 1-(2-naphthyl) ethanol and Tröger’s base, CSP-2 gave the highest separation ability in all of CSPs. On the other hand, when the DP of cellulose was in a range from 39 to 220, the chiral separation abilities of CDMPCs increased as the DP increased. This work demonstrates that the structure of cellulose esters such as DS and DP has important effect on their chiral separation ability, and therefore provides a practical method to design and prepare desirable CSPs for different racemates.
Co-reporter:Peng Xiao;Jinming Zhang;Ye Feng;Jin Wu;Jiasong He
Cellulose 2014 Volume 21( Issue 4) pp:2369-2378
Publication Date(Web):2014 August
DOI:10.1007/s10570-014-0256-9
Using ionic liquid 1-allyl-3-methylimidazolium chloride as reaction medium, a series of novel cellulose esters containing phosphorus including cellulose diphenyl phosphate (C-Dp) and cellulose acetate (CA)–diphenyl phosphate mixed esters was synthesized homogeneously. The degree of substitution was well controlled by altering reaction conditions, such as the molar ratio of the acylating reagents/anhydroglucose unit and reaction time. The structure and thermal properties of cellulose esters were characterized by FTIR, NMR, wide-angle X-ray powder diffraction and differential scanning calorimetry. All the products possessed excellent solubility in some common organic solvents, and transparent films of cellulose esters were obtained by solution casting. In contrast to C-Dp, CA–diphenyl phosphate mixed esters showed clear glass transitions. More interestingly, these cellulose mixed esters exhibited thermoplastic behavior and could be processed by traditional melt processing methods.
Co-reporter:Jing Chen;Jin-ming Zhang;Ye Feng;Jia-song He
Chinese Journal of Polymer Science 2014 Volume 32( Issue 1) pp:1-8
Publication Date(Web):2014 January
DOI:10.1007/s10118-014-1384-2
In this work, four kinds of cellulose aliphatate esters, cellulose acetate (CA), cellulose propionate (CP), cellulose butyrate (CB) and cellulose acetate butyrate (CAB) are synthesized by the homogeneous acylation reactions in cellulose/AmimCl solutions. These cellulose aliphatate esters are used to prepare gas separation membranes and the effects of molecular structure, such as substituent type, degree of substitution (DS) and distribution of substituents, on the gas permeability are studied. For CAs, as the DS increases, their gas permeabilities for all five gases (O2, N2, CH4, CO and CO2) increase, and the ideal permselectivity significantly increases first and then slightly decreases. At similar DS value, the homogenously synthesized CA (distribution order of acetate substituent: C6 > C3 > C2) is superior to the heterogeneously synthesized CA (distribution order of acetate substituent: C3 > C2 > C6) in gas separation. With the increase of chain length of aliphatate substituents from acetate to propionate, and to butyrate, the gas permeability of cellulose aliphatate esters gradually increases. The cellulose mixed ester CAB with short acetate groups and relatively long butyrate groups exhibits higher gas permeability or better permselectivity than individual CA or CB via the alteration of the DS of two substituents.
Co-reporter:Jing Chen, Jinming Zhang, Ye Feng, Jin Wu, Jiasong He, Jun Zhang
Journal of Membrane Science 2014 469() pp: 507-514
Publication Date(Web):
DOI:10.1016/j.memsci.2014.06.010
Co-reporter:Yihao Luan, Jinming Zhang, Maosheng Zhan, Jin Wu, Jun Zhang, Jiasong He
Carbohydrate Polymers 2013 Volume 92(Issue 1) pp:307-311
Publication Date(Web):30 January 2013
DOI:10.1016/j.carbpol.2012.08.111
Using 4-dimethylaminopyridine (DMAP) as the catalyst, highly efficient propionylation and butyralation of cellulose were successfully carried out in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) under mild conditions. Cellulose propionate (CP) and cellulose butyrate (CB) with a degree of substitution (DS) in the range from 0.89 to 2.89 were synthesized within only 30 min at 30 °C. The DS values of the products could be well controlled just by molar ratio of acid anhydride/anhydroglucose unit (AGU). More interestingly, the conversions of acid anhydrides in both propionylation and butyralation were as high as above 90%, even 96%. Therefore, this work provides a facile and highly efficient way for the synthesis of cellulose esters CP and CB.Highlights► Finding an effective catalyst for propionylation and butyralation of cellulose in ionic liquid. ► Synthesizing CP and CB under mild reaction conditions. ► Resultant CP and CB with DS from 0.89 to 2.89. ► Controlling DS of products by molar ratio of acid anhydride/AGU. ► Conversions of acid anhydrides in both reactions as high as 90%, even above 96%.
Co-reporter:Hongzan Song, Yanhua Niu, Jian Yu, Jun Zhang, Zhigang Wang and Jiasong He
Soft Matter 2013 vol. 9(Issue 11) pp:3013-3020
Publication Date(Web):05 Feb 2013
DOI:10.1039/C3SM27320B
Spherulites of microcrystalline cellulose (MCC) have been prepared by using the vapor precipitation procedure with proper humidity at various temperatures from concentrated microcrystalline cellulose/1-allyl-3-methylimidazolium chloride (MCC/AMIMCl) solutions, for which AMIMCl is an ionic liquid, a good solvent for dissolving MCC. Four different types of MCC spherulites have been investigated by using polarizing optical microscopy (POM), scanning electron microscopy (SEM) and wide-angle X-ray diffraction (WAXD) technique. POM observations reveal four types of MCC spherulites, i.e., negative and positive banded spherulites, and negative and positive non-banded spherulites, depending on MCC concentration and crystallization temperature (Tc). For banded spherulites, both the band spacing and sizes of spherulites evidently increase with increasing Tc for each MCC/AMIMCl solution. The sizes of spherulites increase with increasing MCC concentration at a given Tc. The findings imply that MCC concentration plays a key role in MCC chain reorganizations into positive or negative spherulites, while the crystallization temperature mainly affects the MCC crystalline lamellar twisting for the formation of banded spherulites. SEM observation reveals that the formation of negative and positive banded spherulites is due to different lamellar twisting directions and the formation of non-banded spherulites is due to the formed radiating fibrillar textures. WAXD profiles confirm that all the four types of MCC spherulites formed are in the crystalline form of cellulose II family, exhibiting more intense and sharper diffraction peaks than those of cellulose II family obtained by the dissolution/precipitation process.
Co-reporter:Hong Xu, Fangfang Tong, Jian Yu, Lixiong Wen, Jun Zhang, and Jiasong He
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 34) pp:11988-11995
Publication Date(Web):2017-2-22
DOI:10.1021/ie400997k
Poly(methyl methacrylate) (PMMA) and sodium montmorillonite (Na-MMT) were melt-blended with 1-dodecyl-3-methylimidazolium hexafluorophosphate (C12mimPF6) to prepare nanocomposites containing well-dispersed MMT layers in nanoscale and freely existed excess C12mimPF6. A synergistic effect of MMT and C12mimPF6 on the foaming behavior of nanocomposites was revealed in this study. At the mild conditions of 17 MPa and 35 °C, neat PMMA and PMMA/C12mimPF6 and PMMA/Na-MMT samples were not foamed, while cells were induced in nanocomposites containing a certain amount of free C12mimPF6. At 25 MPa/90 °C, foamed nanocomposites exhibited higher nucleation efficiency and cell density, and smaller cell sizes with narrower size distribution than that of neat PMMA and those binary samples. The results indicated that the MMT nanoparticles produced heterogeneous nucleation, and increased the modulus of polymer matrix to depress cell coalescence. The presence of free C12mimPF6 decreased the energy barrier for cell nucleation and facilitated the dispersion of MMT nanoparticles via in situ organic modification.
Co-reporter:Nan Luo, Yuxia Lv, Dexiu Wang, Jinming Zhang, Jin Wu, Jiasong He and Jun Zhang
Chemical Communications 2012 vol. 48(Issue 50) pp:6283-6285
Publication Date(Web):30 Apr 2012
DOI:10.1039/C2CC31483E
Taking advantage of the negligible vapor pressure and dissolving features of ionic liquids (ILs), the solution morphology and dissolution process of cellulose in ILs have been visualized directly by conventional transmission electron microscopy (TEM) at room temperature for the first time.
Co-reporter:Nan Luo, K. Varaprasad, G. Venkata Subba Reddy, A. Varada Rajulu and Jun Zhang
RSC Advances 2012 vol. 2(Issue 22) pp:8483-8488
Publication Date(Web):17 Jul 2012
DOI:10.1039/C2RA21465B
Water-insoluble curcumin was found to be well dissolved in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl), which is also an effective solvent for cellulose. Using AmimCl as the solvent, cellulose/curcumin composite films with various curcumin contents ranging from 0 to 5 wt% were prepared by solution-mixing and casting. The obtained films containing curcumin were highly transparent with a bright yellow color. These composite films possessed good mechanical properties and thermal stability, both of which are comparable to the pure cellulose films. The SEM observation of the fracture surface of the cellulose/curcumin composite films indicated the uniform distribution of curcumin in the matrix. The antibacterial activity of the composite films was examined by a zone method against E. coli. The results showed that the cellulose/curcumin composite films exhibited obvious antibacterial activity, and the inhibition zone diameter against the bacterium was proportional to the curcumin content in the composite films. Hence, these cellulose/curcumin composite films prepared entirely from natural resources can be considered as novel kinds of functional films and could find applications in food packaging and medical fields.
Co-reporter:Yuxia Lv, Jin Wu, Jinming Zhang, Yanhua Niu, Chen-Yang Liu, Jiasong He, Jun Zhang
Polymer 2012 Volume 53(Issue 12) pp:2524-2531
Publication Date(Web):25 May 2012
DOI:10.1016/j.polymer.2012.03.037
Rheological properties of cellulose dissolved in two ionic liquids (ILs), 1-allyl-3-methylimidazolium chloride (AmimCl) and 1-butyl-3-methylimidazolium chloride (BmimCl), with co-solvent dimethylsulfoxide (DMSO), are studied in the concentration range of cellulose from 0.070 to 6.0 wt%. The viscosities of ILs are exponentially decreased by adding DMSO in the concentration range of 0–100 wt%. The co-solvent DMSO decreases the monomer friction coefficient in cellulose solutions and has no significant change for the entanglement state of cellulose, thus results in the reduced solution viscosity, shortened relaxation time and unchanged moduli of the cross-over point. For cellulose solutions, dilute regime, semidilute unentangled regime and semidilute entangled regime were determined by steady shear experiments. In semidilute entangled regime, the specific viscosities ηsp, relaxation time τ, and plateau modulus GN, exhibit concentration dependences as ηsp ∼ C4.4, τ ∼ C2.2, andGN ∼ C1.9, respectively, in AmimCl-DMSO (80/20 w/w); and ηsp ∼ C4.3, τ ∼ C2.0, and GN ∼ C2.1, respectively, in BmimCl–DMSO (80/20 w/w). Therefore, the rheological properties of cellulose/IL/DMSO solutions are approximately of IL-independence in this study. The dependence of ηsp upon cellulose concentration shows that the IL–DMSO mixture is more like a θ solvent for cellulose, and the thermodynamic properties of IL–DMSO mixtures are similar with those of ILs for cellulose at 25 °C. The conformation of cellulose in ILs would not be changed with the addition of DMSO not only in the dilute regime but also in the entanglement regime.Graphical abstract
Co-reporter:Yan Cao, Huiquan Li, and Jun Zhang
Industrial & Engineering Chemistry Research 2011 Volume 50(Issue 13) pp:7808-7814
Publication Date(Web):May 14, 2011
DOI:10.1021/ie2004362
Cellulose acetate butyrate (CAB) with butyryl content of 6–47 wt % was homogeneously synthesized in 1-allyl-3-methylimidazolium chloride (AmimCl) in a single step without using any catalysts. The effects of different acylating agents (acetic anhydride and butyric anhydride) addition methods and reaction conditions on the acyl content of CABs were investigated. Synthesized CABs were characterized by FTIR, NMR, solubility, and thermal analysis. The acylating agents addition method influences the butyryl content, substituent distribution within the anhydroglucose units (AGU), and the properties of CAB. The CAB obtained with butyryl content greater than 38% is completely soluble in 2-methyl–ethyl ketone, 1,2-dichloromethane, ethyl acetate, and butyl acetate. After the mix-acylation, AmimCl can be easily recycled and reused. This study provides a novel way for the clean production of CAB under mild conditions for future industrial applications.
Co-reporter:Qiaofeng Lan, Jian Yu, Jun Zhang, and Jiasong He
Macromolecules 2011 Volume 44(Issue 14) pp:5743-5749
Publication Date(Web):June 22, 2011
DOI:10.1021/ma102797r
The crystallization behavior of thin bisphenol A polycarbonate (PC) films after treatment in supercritical CO2 (ScCO2) was investigated by using polarized optical microscopy (POM) and atomic force microscopy (AFM). Experimental results indicated that the crystallization ability in thin PC film of 259 nm thick was higher than that in the bulk in a much wider temperature range, and the crystallization window was further broadened when the thickness of samples decreased. The 15 nm film crystallized under 20 MPa CO2 at 60 °C, i.e., more than 90 K below the glass transition temperature of the bulk at ambient pressure, while the 259 nm film remained amorphous under the same treatment condition. The results further revealed that crystalline morphology was affected by the CO2 treatment condition and film thickness. And the 7 nm film dewetted the substrate in the treatment at 20 MPa/60 °C instead of crystallization. It was indicated that chain mobility of the polymer was strongly increased in ScCO2 when the film thickness was decreased to the scale of radius of gyration (ca. 6 nm) of the polymer. A modified three-layer model was proposed to explain these findings by introducing the effect of CO2 adsorption. The excess CO2 adsorbed at the free surface and polymer/substrate interface enlarged portions of these two layers and enhanced the polymer mobility therein, which took effect in thin films with thickness from hundreds down to several nanometers.
Co-reporter:Hongzan Song, Yanhua Niu, Zhigang Wang, and Jun Zhang
Biomacromolecules 2011 Volume 12(Issue 4) pp:
Publication Date(Web):March 1, 2011
DOI:10.1021/bm101426p
Liquid crystalline (LC) phase transition and gel−sol transition in the solutions of microcrystalline cellulose (MCC) and ionic liquid (1-ethyl-3-methylimidazolium acetate, EMIMAc) have been investigated through a combination of polarized optical microscope (POM) observation and rheological measurements. Molecular LC phase forms at the 10 wt % cellulose concentration, as observed by POM, whereas the critical gel point is 12.5 wt % by rheological measurements according to the Winter and Chambon theory, for which the loss tangent, tan δ, shows frequency independence. Dramatic decreases of G′ and G′′ in the phase transition temperature range during temperature sweep are observed due to disassembling of the LC domain junctions. The phase diagram describing the LC phase and gel−sol transitions is obtained and the associated mechanisms are elucidated. A significant feature shown in the phase diagram is the presence of a narrow lyotropic LC solution region, which potentially has a great importance for the cellulose fiber wet spinning.
Co-reporter:Jinming Zhang, Hao Zhang, Jin Wu, Jun Zhang, Jiasong He and Junfeng Xiang
Physical Chemistry Chemical Physics 2010 vol. 12(Issue 8) pp:1941-1947
Publication Date(Web):19 Jan 2010
DOI:10.1039/B920446F
The dissolution mechanism of cellulose in ionic liquids has been investigated by using cellobiose and 1-ethyl-3-methylimidazolium acetate (EmimAc) as a model system under various conditions with conventional and variable-temperature NMR spectroscopy. In DMSO-d6 solution, NMR data of the model system clearly suggest that hydrogen bonding is formed between hydroxyls of cellobiose and both anion and cation of EmimAc. The CH3COO− anion favors the formation of hydrogen bonds with hydrogen atoms of hydroxyls, and the aromatic protons in bulky cation [Emim]+, especially the most acidic H2, prefer to associate with the oxygen atoms of hydroxyls with less steric hindrance, while after acetylation of all hydroxyls in cellobiose the interactions between cellobiose octaacetate and EmimAc become very weak, implying that hydrogen bonding is the major reason of cellobiose solvation in EmimAc. Meanwhile the stoichiometric ratio of EmimAc/hydroxyl is estimated to be between 3:4 and 1:1 in the primary solvation shell, suggesting that there should be one anion or cation to form hydrogen bonds with two hydroxyl groups simultaneously. In situ and variable-temperature NMR spectra suggest the above mechanism also works in the real system.
Co-reporter:Jinming Zhang, Hao Zhang, Jin Wu, Jun Zhang, Jiasong He and Junfeng Xiang
Physical Chemistry Chemical Physics 2010 vol. 12(Issue 44) pp:14829-14830
Publication Date(Web):19 Oct 2010
DOI:10.1039/C005453B
A graphical abstract is available for this content
Co-reporter:Tao Meng, Xia Gao, Jun Zhang, Jinying Yuan, Yuzhu Zhang, Jiasong He
Polymer 2009 50(2) pp: 447-454
Publication Date(Web):
DOI:10.1016/j.polymer.2008.11.011
Co-reporter:Jinming Zhang;Jin Wu;Yan Cao;Shengmei Sang;Jiasong He
Cellulose 2009 Volume 16( Issue 2) pp:299-308
Publication Date(Web):2009/04/01
DOI:10.1007/s10570-008-9260-2
The ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as a reaction medium was studied for the synthesis of cellulose benzoates by homogeneous acylation of dissolved cellulose with benzoyl chlorides in the absence of any catalysts. Cellulose benzoates with a degree of substitution (DS) in the range from about 1 to 3.0 were accessible under mild conditions. The DS of cellulose derivatives increased with the increase of the molar ratio of benzoyl chloride/anhydroglucose unit (AGU) in cellulose, reaction time, and reaction temperature. Benzoylation of cellulose with some 4-substituted benzoyl chlorides including 4-toluoyl chloride, 4-chlorobenzoyl chloride and 4-nitrobenzoyl chloride was also readily carried out under mild conditions. Furthermore, regioselectively substituted mixed cellulose esters were synthesized in this work. All products were characterized by means of FT-IR, 1H-NMR, and 13C-NMR spectroscopy. In addition, at the end of benzoylation of cellulose, the ionic liquid AmimCl was easily recycled. When the recycled AmimCl was used as the reaction media, the cellulose benzoate with a similar DS was obtained under comparable reaction conditions.
Co-reporter:Chenghu Yan, Jinming Zhang, Yuxia Lv, Jian Yu, Jin Wu, Jun Zhang and Jiasong He
Biomacromolecules 2009 Volume 10(Issue 8) pp:
Publication Date(Web):July 10, 2009
DOI:10.1021/bm900447u
An effective method for grafting l-lactide (LA) from unmodified cellulose by ring-opening polymerization (ROP) in homogeneous mild conditions is presented. By using 4-dimethylaminopyridine (DMAP) as an organic catalyst, cellulose-graft-poly(l-lactide) (cellulose-g-PLLA) copolymers with a molar substitution (MSPLLA) of PLLA in a range of 0.99−12.28 were successfully synthesized in ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) at 80 °C. The amount and length of grafted PLLA in cellulose-g-PLLA copolymers were controlled by adjusting the molar ratios of LA monomer to cellulose. The structure and thermal properties of cellulose-g-PLLA copolymers were characterized by 1H NMR, 13C NMR, wide-angle X-ray powder diffraction (WAXD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and optical microscopy. The DSC results revealed that the copolymers exhibited a single glass transition temperature, Tg, which sharply decreased with the increase of MSPLLA up to MSPLLA = 8.28 (DSPLLA = 2.19) and increased a little with a further increase of the lactyl content. When MSPLLA was above 4.40, the graft copolymers exhibited thermoplastic behavior, indicating the intermolecular and intramolecular hydrogen bonds in cellulose molecules had been effectively destroyed. By using a conventional thermal processing method, fibers and disks of cellulose-g-PLLA copolymers were prepared.
Co-reporter:Ling Xiang, Zhinan Zhang, Ping Yu, Jun Zhang, Lei Su, Takeo Ohsaka and Lanqun Mao
Analytical Chemistry 2008 Volume 80(Issue 17) pp:6587
Publication Date(Web):August 1, 2008
DOI:10.1021/ac800733t
This study demonstrates a new and relatively general route to the development of multiwalled carbon nanotube (MWNT)-based integrative electrochemical biosensors by confining ferricyanide redox mediator onto MWNTs. The ferricyanide-confined MWNTs are synthesized first through grafting of epoxy chloropropane onto MWNTs with in situ cationic ring-opening polymerization and then introducing the positively charged methylimidazolium moieties into the grafted polymer with a quaternization reaction. The grafted polymers with positively charged methylimidazolium moieties tethered onto MWNTs can essentially be used to confine redox-active ferricyanide onto MWNTs to form a redox mediator-confined nanocomposite with a good stability and excellent electrochemical property. The synthetic nanocomposite with surface-confined ferricyanide is demonstrated to be well-competent as the efficient electronic transducers for the general development of electrochemical biosensors upon combination with biorecognition units, which is illustrated by using glucose oxidase and laccase as two model biorecognition units. This study essentially paves a facile and general approach to the development of integrative nanostructured electrochemical biosensors.
Co-reporter:Xiaofeng Sui, Jinying Yuan, Mi Zhou, Jun Zhang, Haijun Yang, Weizhong Yuan, Yen Wei and Caiyuan Pan
Biomacromolecules 2008 Volume 9(Issue 10) pp:
Publication Date(Web):September 6, 2008
DOI:10.1021/bm800538d
Cellulose-graft-poly(N,N-dimethylamino-2-ethyl methacrylate) (cellulose-g-PDMAEMA) copolymers were prepared by homogeneous atom transfer radical polymerization (ATRP) under mild conditions. Cellulose macroinitiator was successfully synthesized by direct acylation of cellulose with 2-bromopropionyl bromide in a room temperature ionic liquid (RTIL), 1-allyl-3-methylimidazolium chloride. Copolymers were obtained via ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA) with CuBr/ pentamethyldiethylenetriamine (PMDETA) as catalyst and N,N-dimethylformamide (DMF) as solvent without homopolymer byproduct. The grafting copolymers were characterized by 1H NMR, FT-IR, and TGA measurements. The results confirmed that PDMAEMA had been covalently bonded to cellulose backbone. Furthermore, the assemblies or aggregates formed by cellulose-g-PDMAEMA copolymers in water were studied at various concentrations, temperatures, and pH values by means of UV, DLS, TEM, and AFM. The results indicate that the copolymers had the pH- and temperature-responsive properties similar to the expected stimuli-responses by PDMAEMA. The synthetic strategy presented here could be employed in the preparation of other novel biomaterials from a variety of polysaccharides.
Co-reporter:H. Zhang;Z. G. Wang;Z. N. Zhang;J. Wu;J. Zhang;J. S. He
Advanced Materials 2007 Volume 19(Issue 5) pp:698-704
Publication Date(Web):7 FEB 2007
DOI:10.1002/adma.200600442
Good dispersion and alignment of multiwalled carbon nanotubes (MWCNTs) in cellulose is achieved by dissolution in an ionic liquid and subsequent grinding and spinning. This simple method of preparing regenerated-cellulose/MWCNT composite fibers could lead to the production of carbon fibers from a renewable resource (cellulose). The figure shows regenerated cellulose (white) and cellulose/MWCNT composite (black) fibers.
Co-reporter:Yan Cao, Jin Wu, Tao Meng, Jun Zhang, Jiasong He, Huiquan Li, Yi Zhang
Carbohydrate Polymers 2007 Volume 69(Issue 4) pp:665-672
Publication Date(Web):2 July 2007
DOI:10.1016/j.carbpol.2007.02.001
Cellulose samples extracted from cornhusk have been successfully acetylated in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). Without using any catalyst, cornhusk cellulose acetates (CCAs) with the degree of substitution (DS) in a range from 2.16 to 2.63 were prepared in one-step. Under the homogeneous state, the DS value of CCAs was easily controlled by the acetylation time. The obtained CCAs were characterized by means of FT-IR, 13C NMR, DSC, TGA, and a mechanical test. The NMR results showed that the distribution of the acetyl moiety among the three OH groups of the anhydroglucose unit shows a preference at the C6 position. The CCAs exhibited good solubility in some organic solvents, such as acetone and DMSO. The cast CCA films from their acetone solutions had good mechanical properties. At the end of each acetylation of cornhusk cellulose, the ionic liquid AmimCl could be effectively recovered. Therefore, this study presents a promising approach and “green process” to make use of crop by-products.
Co-reporter:Zhinan Zhang, Jun Zhang, Peng Chen, Baoqing Zhang, Jiasong He, Guo-Hua Hu
Carbon 2006 Volume 44(Issue 4) pp:692-698
Publication Date(Web):April 2006
DOI:10.1016/j.carbon.2005.09.027
The effect of melt mixing on the interaction between multi-walled carbon nanotubes (MWNTs) and polystyrene (PS) matrix has been investigated. The interaction between pristine MWNTs and PS in solution was found to exist but not strong enough to allow MWNTs to be soluble in solvent. In contrast, this interaction between MWNTs and PS was significantly enhanced by melt mixing, which led to increased amount of PS-functionalized MWNT exhibiting good solubility in some solvents. The mechanism of melt mixing on this enhanced interaction was attributed to both chemical bonding and physical interaction during the melt mixing.
Co-reporter:Yan CAO, Jun ZHANG, Jiasong HE, Huiquan LI, Yi ZHANG
Chinese Journal of Chemical Engineering (2010) Volume 18(Issue 3) pp:515-522
Publication Date(Web):1 January 2010
DOI:10.1016/S1004-9541(10)60252-2
At relatively high cellulose mass concentrations (8%, 10%, and 12%), homogeneous acetylation of cellulose was carried out in an ionic liquid, 1-allyl-3-methylimidazolium chloride (AmimCl). Without using any catalyst, cellulose acetates (CAs) with the degree of substitution (DS) in a range from 0.4 to 3.0 were synthesized in one-step. The effects of reaction time, temperature and molar ratio of acetic anhydride/anhydroglucose unit (AGU) in cellulose on DS value of CAs were investigated. The synthesized CAs were characterized by means of FT-IR, NMR, and solubility, mechanical and thermal tests. After the acetylation, the used ionic liquid AmimCl was easily recycled and reused. This study shows the potential of the homogeneous acetylation of cellulose at relatively high concentrations in ionic liquids in future industrial applications.
Co-reporter:Nan Luo, Yuxia Lv, Dexiu Wang, Jinming Zhang, Jin Wu, Jiasong He and Jun Zhang
Chemical Communications 2012 - vol. 48(Issue 50) pp:NaN6285-6285
Publication Date(Web):2012/04/30
DOI:10.1039/C2CC31483E
Taking advantage of the negligible vapor pressure and dissolving features of ionic liquids (ILs), the solution morphology and dissolution process of cellulose in ILs have been visualized directly by conventional transmission electron microscopy (TEM) at room temperature for the first time.
Co-reporter:Jinming Zhang, Hao Zhang, Jin Wu, Jun Zhang, Jiasong He and Junfeng Xiang
Physical Chemistry Chemical Physics 2010 - vol. 12(Issue 44) pp:NaN14830-14830
Publication Date(Web):2010/10/19
DOI:10.1039/C005453B
A graphical abstract is available for this content
Co-reporter:Jinming Zhang, Jin Wu, Jian Yu, Xiaoyu Zhang, Jiasong He and Jun Zhang
Inorganic Chemistry Frontiers 2017 - vol. 1(Issue 7) pp:NaN1290-1290
Publication Date(Web):2017/01/16
DOI:10.1039/C6QM00348F
Cellulose, a well-known fascinating biopolymer, has been considered to be a sustainable feedstock of energy sources and chemical engineering in the future. However, due to its highly ordered structure and strong hydrogen bonding network, cellulose is neither meltable nor soluble in conventional solvents, which limits the extent of its application. Therefore, the search for powerful and eco-friendly solvents for cellulose processing has been a key issue in this field for decades. More recently, certain ionic liquids (ILs) have been found to be able to efficiently dissolve cellulose, providing a new and versatile platform for cellulose processing and functionalization. A series of cellulose-based materials, such as films, fibers, gels and composites, have been produced readily with the aid of ILs. This review article highlights recent advances in the field of dissolution and processing of cellulose with ILs. It is hoped that this review work will stimulate a wide range of research studies and collaborations, leading to significant progress in this area.
Co-reporter:Jinming Zhang, Hao Zhang, Jin Wu, Jun Zhang, Jiasong He and Junfeng Xiang
Physical Chemistry Chemical Physics 2010 - vol. 12(Issue 8) pp:NaN1947-1947
Publication Date(Web):2010/01/19
DOI:10.1039/B920446F
The dissolution mechanism of cellulose in ionic liquids has been investigated by using cellobiose and 1-ethyl-3-methylimidazolium acetate (EmimAc) as a model system under various conditions with conventional and variable-temperature NMR spectroscopy. In DMSO-d6 solution, NMR data of the model system clearly suggest that hydrogen bonding is formed between hydroxyls of cellobiose and both anion and cation of EmimAc. The CH3COO− anion favors the formation of hydrogen bonds with hydrogen atoms of hydroxyls, and the aromatic protons in bulky cation [Emim]+, especially the most acidic H2, prefer to associate with the oxygen atoms of hydroxyls with less steric hindrance, while after acetylation of all hydroxyls in cellobiose the interactions between cellobiose octaacetate and EmimAc become very weak, implying that hydrogen bonding is the major reason of cellobiose solvation in EmimAc. Meanwhile the stoichiometric ratio of EmimAc/hydroxyl is estimated to be between 3:4 and 1:1 in the primary solvation shell, suggesting that there should be one anion or cation to form hydrogen bonds with two hydroxyl groups simultaneously. In situ and variable-temperature NMR spectra suggest the above mechanism also works in the real system.
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![1,2,3,4-Butanetetrol,1-[5-[(2S,3R)-2,3,4-trihydroxybutyl]-2-pyrazinyl]-, (1R,2S,3R)-](http://img.cochemist.com/ccimg/17500/17460-13-8.png)
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![2-[(o-nitrophenyl)azo]-p-cresol](http://img.cochemist.com/ccimg/1500/1435-71-8.png)
![2-[(o-nitrophenyl)azo]-p-cresol](http://img.cochemist.com/ccimg/1500/1435-71-8_b.png)
![[1,3]dioxolo[4,5-j]phenanthridine](http://img.cochemist.com/ccimg/300/224-11-3.png)
![[1,3]dioxolo[4,5-j]phenanthridine](http://img.cochemist.com/ccimg/300/224-11-3_b.png)
![Methanimidamide, N-[2,6-bis(1-methylethyl)phenyl]-N'-(2,4,6-trimethylphenyl)-](/data/chemimg/154200/1118917-00-2.png)
![Methanimidamide, N-[2,6-bis(1-methylethyl)phenyl]-N'-(2,4,6-trimethylphenyl)-](/data/chemimg/154200/1118917-00-2_b.png)
![Formamide, N-(2,4,6-trimethylphenyl)-N-[2-[(2,4,6-trimethylphenyl)amino]ethyl]-](/data/chemimg/154200/1060651-06-0.png)
![Formamide, N-(2,4,6-trimethylphenyl)-N-[2-[(2,4,6-trimethylphenyl)amino]ethyl]-](/data/chemimg/154200/1060651-06-0_b.png)
![Methanimidamide, N-[2,6-bis(1-methylethyl)phenyl]-N'-(2-methylphenyl)-](/data/chemimg/154200/1025068-43-2.png)
![Methanimidamide, N-[2,6-bis(1-methylethyl)phenyl]-N'-(2-methylphenyl)-](/data/chemimg/154200/1025068-43-2_b.png)
![Bicyclo[4.1.0]heptan-2-one, 7-nitro-, (1S,6R,7S)-](http://img.cochemist.com/ccimg/919600/919530-30-6.png)
![Bicyclo[4.1.0]heptan-2-one, 7-nitro-, (1S,6R,7S)-](http://img.cochemist.com/ccimg/919600/919530-30-6_b.png)
![1,3-Propanediol, 2,2-bis[(4S)-4-(1,1-dimethylethyl)-4,5-dihydro-2-oxazolyl]-](/data/chemimg/106800/871576-28-2.png)
![1,3-Propanediol, 2,2-bis[(4S)-4-(1,1-dimethylethyl)-4,5-dihydro-2-oxazolyl]-](/data/chemimg/106800/871576-28-2_b.png)
![Anthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetrone, 5,12-dibromo-2,9-dibutyl-](/data/chemimg/106800/861853-30-7.png)
![Anthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetrone, 5,12-dibromo-2,9-dibutyl-](/data/chemimg/106800/861853-30-7_b.png)
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![N-[3,5-Bis(trifluoromethyl)phenyl]-N-[(8a,9S)-6-methoxy-9-cinchonanyl]thiourea](/data/chemimg/103500/852913-16-7.png)
![N-[3,5-Bis(trifluoromethyl)phenyl]-N-[(8a,9S)-6-methoxy-9-cinchonanyl]thiourea](/data/chemimg/103500/852913-16-7_b.png)
![1,3-Propanediol, 2,2-bis[(3aR,8aS)-3a,8a-dihydro-8H-indeno[1,2-d]oxazol-2-yl]-](/data/chemimg/106800/361503-29-9.png)
![1,3-Propanediol, 2,2-bis[(3aR,8aS)-3a,8a-dihydro-8H-indeno[1,2-d]oxazol-2-yl]-](/data/chemimg/106800/361503-29-9_b.png)
![Benzaldehyde, 2-[(2,4,6-trimethylphenyl)amino]-](/data/chemimg/106700/330666-00-7.png)
![Benzaldehyde, 2-[(2,4,6-trimethylphenyl)amino]-](/data/chemimg/106700/330666-00-7_b.png)
![1H-Imidazole,1-[(2R)-2-(2,4-dichlorophenyl)-2-[(2,6-dichlorophenyl)methoxy]ethyl]-](http://img.cochemist.com/ccimg/322800/322764-97-6.png)
![1H-Imidazole,1-[(2R)-2-(2,4-dichlorophenyl)-2-[(2,6-dichlorophenyl)methoxy]ethyl]-](http://img.cochemist.com/ccimg/322800/322764-97-6_b.png)
![1H-Imidazole,1-[(2S)-2-(2,4-dichlorophenyl)-2-[(2,6-dichlorophenyl)methoxy]ethyl]-](http://img.cochemist.com/ccimg/322800/322764-96-5.png)
![1H-Imidazole,1-[(2S)-2-(2,4-dichlorophenyl)-2-[(2,6-dichlorophenyl)methoxy]ethyl]-](http://img.cochemist.com/ccimg/322800/322764-96-5_b.png)
![Ruthenate(4-), carbonyl[[4,4',4'',4'''-(21H,23H-porphine-5,10,15,20-tetrayl-κN21,κN22,κN23,κN24)tetrakis[benzoato]](6-)]-, hydrogen (1:4), (SP-5-31)-](/data/chemimg/106700/148651-63-2.png)
![Ruthenate(4-), carbonyl[[4,4',4'',4'''-(21H,23H-porphine-5,10,15,20-tetrayl-κN21,κN22,κN23,κN24)tetrakis[benzoato]](6-)]-, hydrogen (1:4), (SP-5-31)-](/data/chemimg/106700/148651-63-2_b.png)
![Benzaldehyde, 2-[(phenylmethyl)amino]-](/data/chemimg/106700/147611-22-1.png)
![Benzaldehyde, 2-[(phenylmethyl)amino]-](/data/chemimg/106700/147611-22-1_b.png)
![Benzenemethanol, 4-nitro-α-[(1R)-1-nitroethyl]-, (αS)-rel-](/data/chemimg/106700/142839-99-4.png)
![Benzenemethanol, 4-nitro-α-[(1R)-1-nitroethyl]-, (αS)-rel-](/data/chemimg/106700/142839-99-4_b.png)
![2,2′-Methylenebis[(4S)-4-tert-butyl-2-oxazoline]](/data/chemimg/106700/132098-54-5.png)
![2,2′-Methylenebis[(4S)-4-tert-butyl-2-oxazoline]](/data/chemimg/106700/132098-54-5_b.png)
![5-Isobenzofurancarbonitrile,1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-, (1R)-](http://img.cochemist.com/ccimg/128200/128196-02-1.png)
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![Methanimidamide, N,N'-bis[1,1'-biphenyl]-2-yl-](/data/chemimg/106700/115293-11-3.png)
![Methanimidamide, N,N'-bis[1,1'-biphenyl]-2-yl-](/data/chemimg/106700/115293-11-3_b.png)
![2H-Pyrano[2,3-d]pyrimidine-6-carbonitrile,7-amino-1,3,4,5-tetrahydro-5-(4-methoxyphenyl)-2,4-dioxo-](http://img.cochemist.com/ccimg/112500/112434-52-3.png)
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![(3R)-N-methyl-3-phenyl-3-[4-(trifluoromethyl)phenoxy]propan-1-amine](http://img.cochemist.com/ccimg/100600/100568-03-4_b.png)
![(S)-N-Methyl-gamma-[4-(trifluoromethyl)phenoxy]benzenepropanamine](http://img.cochemist.com/ccimg/100600/100568-02-3.png)
![(S)-N-Methyl-gamma-[4-(trifluoromethyl)phenoxy]benzenepropanamine](http://img.cochemist.com/ccimg/100600/100568-02-3_b.png)
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![2H-Pyrano[2,3-d]pyrimidine-6-carbonitrile, 7-amino-5-(4-chlorophenyl)-1,3,4,5-tetrahydro-2,4-dioxo-](/data/chemimg/2072700/94988-87-1.png)
![2H-Pyrano[2,3-d]pyrimidine-6-carbonitrile, 7-amino-5-(4-chlorophenyl)-1,3,4,5-tetrahydro-2,4-dioxo-](/data/chemimg/2072700/94988-87-1_b.png)
![2H-Pyrano[2,3-d]pyrimidine-6-carbonitrile, 7-amino-1,3,4,5-tetrahydro-2,4-dioxo-5-phenyl-](/data/chemimg/2074500/94988-86-0.png)
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![2H-Pyrano[2,3-d]pyrimidine-6-carbonitrile, 7-amino-1,3,4,5-tetrahydro-5-(3-nitrophenyl)-2,4-dioxo-](/data/chemimg/2074500/94988-66-6.png)
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![2-(2-hydroxyethyl)-6-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione](/data/chemimg/1410200/92060-89-4.png)
![2-(2-hydroxyethyl)-6-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione](/data/chemimg/1410200/92060-89-4_b.png)
![3-Oxabicyclo[3.1.0]hexan-2-one, 6-phenyl-](http://img.cochemist.com/ccimg/88600/88539-24-6.png)
![3-Oxabicyclo[3.1.0]hexan-2-one, 6-phenyl-](http://img.cochemist.com/ccimg/88600/88539-24-6_b.png)
![2H-Pyrano[2,3-d]pyrimidine-6-carbonitrile,7-amino-5-(4-bromophenyl)-1,3,4,5-tetrahydro-2,4-dioxo-](http://img.cochemist.com/ccimg/86000/85992-61-6.png)
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![2H-Pyrano[2,3-d]pyrimidine-6-carbonitrile,7-amino-5-(4-fluorophenyl)-1,3,4,5-tetrahydro-2,4-dioxo-](http://img.cochemist.com/ccimg/86000/85992-60-5.png)
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![BENZAMIDE, N-[1-(4-METHOXYPHENYL)ETHYL]-3,5-DINITRO-](http://img.cochemist.com/ccimg/75000/74927-87-0_b.png)
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![Propanoic acid, 2-[[(4-methylphenyl)sulfonyl]oxy]-, methyl ester, (S)-](http://img.cochemist.com/ccimg/71300/71283-66-4_b.png)
![Propanoic acid, 2-[[(4-methylphenyl)sulfonyl]oxy]-, methyl ester](http://img.cochemist.com/ccimg/66700/66648-29-1.png)
![Propanoic acid, 2-[[(4-methylphenyl)sulfonyl]oxy]-, methyl ester](http://img.cochemist.com/ccimg/66700/66648-29-1_b.png)
![1H-BENZ[DE]ISOQUINOLINE-1,3(2H)-DIONE, 6-AMINO-2-(2-HYDROXYETHYL)-](/data/chemimg/2344800/58232-18-1.png)
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![2-(4-CHLOROPHENYL)BENZO[DE]ISOQUINOLINE-1,3-DIONE](/data/chemimg/80800/53270-74-9.png)
![2-(4-CHLOROPHENYL)BENZO[DE]ISOQUINOLINE-1,3-DIONE](/data/chemimg/80800/53270-74-9_b.png)
![1H-Imidazole,1-[(2S)-2-(2,4-dichlorophenyl)-2-[(2,4-dichlorophenyl)methoxy]ethyl]-](http://img.cochemist.com/ccimg/47500/47447-52-9.png)
![1H-Imidazole,1-[(2S)-2-(2,4-dichlorophenyl)-2-[(2,4-dichlorophenyl)methoxy]ethyl]-](http://img.cochemist.com/ccimg/47500/47447-52-9_b.png)
![N-(2,2-DINITROETHYL)-N-[2-[2,2-DINITROETHYL(NITRO)AMINO]ETHYL]NITRAMIDE](/data/chemimg/61900/41792-58-9.png)
![N-(2,2-DINITROETHYL)-N-[2-[2,2-DINITROETHYL(NITRO)AMINO]ETHYL]NITRAMIDE](/data/chemimg/61900/41792-58-9_b.png)
![Benzenemethanol, α-[(1R)-1-nitroethyl]-, (αR)-rel-](/data/chemimg/3769800/38316-08-4.png)
![Benzenemethanol, α-[(1R)-1-nitroethyl]-, (αR)-rel-](/data/chemimg/3769800/38316-08-4_b.png)
![Poly[oxycarbonyloxy(methyl-1,2-ethanediyl)]](http://img.cochemist.com/ccimg/37300/37248-85-4.png)
![Poly[oxycarbonyloxy(methyl-1,2-ethanediyl)]](http://img.cochemist.com/ccimg/37300/37248-85-4_b.png)
![1H-Furo[3,4-d]imidazole-2,4-dione,tetrahydro-1,3-bis(phenylmethyl)-, (3aS,6aR)-](http://img.cochemist.com/ccimg/28100/28092-62-8.png)
![1H-Furo[3,4-d]imidazole-2,4-dione,tetrahydro-1,3-bis(phenylmethyl)-, (3aS,6aR)-](http://img.cochemist.com/ccimg/28100/28092-62-8_b.png)
![1H-Thieno[3,4-d]imidazole-2,4-dione,tetrahydro-1,3-bis(phenylmethyl)-, (3aS,6aR)-](http://img.cochemist.com/ccimg/28100/28092-52-6.png)
![1H-Thieno[3,4-d]imidazole-2,4-dione,tetrahydro-1,3-bis(phenylmethyl)-, (3aS,6aR)-](http://img.cochemist.com/ccimg/28100/28092-52-6_b.png)
![Poly[oxy[(1S)-1-methyl-2-oxo-1,2-ethanediyl]]](http://img.cochemist.com/ccimg/26200/26161-42-2.png)
![Poly[oxy[(1S)-1-methyl-2-oxo-1,2-ethanediyl]]](http://img.cochemist.com/ccimg/26200/26161-42-2_b.png)
![Ethyl [(4-methylphenyl)amino]acetate](http://img.cochemist.com/ccimg/22000/21911-68-2.png)
![Ethyl [(4-methylphenyl)amino]acetate](http://img.cochemist.com/ccimg/22000/21911-68-2_b.png)
![Benzamide,N-[(1R)-1-phenylethyl]-](http://img.cochemist.com/ccimg/20900/20826-48-6.png)
![Benzamide,N-[(1R)-1-phenylethyl]-](http://img.cochemist.com/ccimg/20900/20826-48-6_b.png)
![Benzene, 1,1'-[(1S)-1-methyl-1,2-ethanediyl]bis-](http://img.cochemist.com/ccimg/19700/19643-68-6.png)
![Benzene, 1,1'-[(1S)-1-methyl-1,2-ethanediyl]bis-](http://img.cochemist.com/ccimg/19700/19643-68-6_b.png)
![3-Oxabicyclo[3.1.0]hexan-2-one, 6,6-dimethyl-](http://img.cochemist.com/ccimg/16900/16860-52-9.png)
![3-Oxabicyclo[3.1.0]hexan-2-one, 6,6-dimethyl-](http://img.cochemist.com/ccimg/16900/16860-52-9_b.png)
![3-OXABICYCLO[3.1.0]HEXAN-2-ONE](http://img.cochemist.com/ccimg/5700/5617-63-0.png)
![3-OXABICYCLO[3.1.0]HEXAN-2-ONE](http://img.cochemist.com/ccimg/5700/5617-63-0_b.png)
![N-[(1S)-1-phenylethyl]benzamide](http://img.cochemist.com/ccimg/4200/4108-58-1.png)
![N-[(1S)-1-phenylethyl]benzamide](http://img.cochemist.com/ccimg/4200/4108-58-1_b.png)
![ethyl N-[4-(trifluoromethyl)phenyl]glycinate](http://img.cochemist.com/ccimg/2500/2445-85-4.png)
![ethyl N-[4-(trifluoromethyl)phenyl]glycinate](http://img.cochemist.com/ccimg/2500/2445-85-4_b.png)
![3',6'-Dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one](http://img.cochemist.com/ccimg/2400/2321-07-5.png)
![3',6'-Dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one](http://img.cochemist.com/ccimg/2400/2321-07-5_b.png)
![(1R,2R,4S,5R)-9-Methyl-3-oxa-9-azatricyclo[3.3.1.02,4]nonan-7-yl 3-hydroxy-2-phenylpropanoate](http://img.cochemist.com/ccimg/200/138-12-5.png)
![(1R,2R,4S,5R)-9-Methyl-3-oxa-9-azatricyclo[3.3.1.02,4]nonan-7-yl 3-hydroxy-2-phenylpropanoate](http://img.cochemist.com/ccimg/200/138-12-5_b.png)
