Co-reporter:Jun You, Shuyi Xie, Jinfeng Cao, Hao Ge, Min Xu, Lina Zhang, and Jinping Zhou
Macromolecules 2016 Volume 49(Issue 3) pp:1049-1059
Publication Date(Web):January 27, 2016
DOI:10.1021/acs.macromol.5b02231
Quaternized chitosan (QCh) was homogeneously synthesized by reacting chitosan with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) in alkali/urea aqueous solution for the first time. The structure and solution properties of QCh were characterized by using element analysis, FT-IR, 13C NMR, SEC-LLS, rheology, viscometer, and ξ-potential measurements. Subsequently, polyelectrolyte complex (PEC) hydrogels were constructed by in situ polymerization of acrylic acid (AA) monomers in the concentrated QCh solution. The structure and mechanical behavior of the prepared hydrogels were systematic studied. Because of the high charge density and solubility of QCh, strong electrostatic interactions were formed in the hydrogels and endowed them tough with self-recovery properties. The mechanical behavior of the hydrogels was accurately tuned from stiff and viscoelastic to soft and elastic by changing the poly(acrylic acid) (PAA) content. The regulation mechanism relied on the remarkable difference in the chain segmental mobility between QCh and PAA. Moreover, the QCh/PAA PEC hydrogels displayed excellent solvent-induced shape-memory behavior due to the reversible properties of the ionic bonds. In summary, we offered a novel modification method for chitosan and opened up a new avenue to construct chitosan-based hydrogels with outstanding mechanical properties.
Co-reporter:Jun You, Jinfeng Cao, Yanteng Zhao, Lina Zhang, Jinping Zhou, and Yun Chen
Biomacromolecules 2016 Volume 17(Issue 9) pp:2839
Publication Date(Web):August 12, 2016
DOI:10.1021/acs.biomac.6b00646
Polysaccharide-based injectable hydrogels have several advantages in the context of biomedical use. However, the main obstruction associated with the utilization of these hydrogels in clinical application is their poor mechanical properties. Herein, we describe in situ gelling of nanocomposite hydrogels based on quaternized cellulose (QC) and rigid rod-like cationic cellulose nanocrystals (CCNCs), which can overcome this challenge. In all cases, gelation immediately occurred with an increase of temperature, and the CCNCs were evenly distributed throughout the hydrogels. The nanocomposite hydrogels exhibited increasing orders-of-magnitude in the mechanical strength, high extension in degradation and the sustained release time, because of the strong interaction between CCNCs and QC chains mediated by the cross-linking agent (β-glycerophosphate, β-GP). The results of the in vitro toxicity and in vivo biocompatibility tests revealed that the hydrogels did not show obvious cytotoxicity and inflammatory reaction to cells and tissue. Moreover, DOX-encapsulated hydrogels were injected beside the tumors of mice bearing liver cancer xenografts to assess the potential utility as localized and sustained drug delivery depot systems for anticancer therapy. The results suggested that the QC/CCNC/β-GP nanocomposite hydrogels had great potential for application in subcutaneous and sustained delivery of anticancer drug to increase therapeutic efficacy and improve patient compliance.
Co-reporter:Feiya Fu, Lingyan Li, Lianjie Liu, Jun Cai, Yaping Zhang, Jinping Zhou, and Lina Zhang
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 4) pp:2597
Publication Date(Web):January 8, 2015
DOI:10.1021/am507639b
Cellulose based ZnO nanocomposite (RCZ) films were prepared from cellulose carbamate–NaOH/ZnO solutions through one-step coagulation in Na2SO4 aqueous solutions. The structure and properties of RCZ films were characterized using XRD, FTIR, XPS, SEM, TEM, TG, tensile testing, and antibacterial activity tests. The content of ZnO in RCZ films was obtained in the range of 2.7–15.1 wt %. ZnO nanoparticles with a hexagonal wurtzite structure agglomerated into large particles, which firmly embedded in the cellulose matrix. RCZ films displayed good mechanical properties and high thermal stability. Moreover, the films exhibited excellent UV-blocking properties and antibacterial activities against Staphylococcus aureus and Escherichia coli. A dramatic reduction in viable bacteria was observed within 3 h of exposure, while all of the bacteria were killed within 6 h. This work provided a novel and simple pathway for the preparation of regenerated cellulose films with ZnO nanoparticles for application as functional biomaterials.Keywords: antibacterial; cellulose; nanocomposite film; one-step coagulation; ZnO nanoparticles
Co-reporter:Haoze Hu, Jun You, Weiping Gan, Jinping Zhou and Lina Zhang
Polymer Chemistry 2015 vol. 6(Issue 18) pp:3543-3548
Publication Date(Web):17 Mar 2015
DOI:10.1039/C5PY00301F
Allyl celluloses (ACs) were synthesized by the reaction of cellulose with allyl chloride in NaOH/urea aqueous solutions. The reaction started homogeneously and ended heterogeneously. The structure and properties of ACs were characterized with SEC-LLS, NMR and solubility testing. The results demonstrated that organo-soluble AC, with a degree of substitution of 0.98–1.65, could be obtained by adjusting the molar ratio of allyl chloride to the anhydroglucose unit of cellulose. A capability evaluation of the click reaction of AC was performed by selecting four thiol compounds. AC-click products were characterized with FT-IR, NMR and elemental analysis, and the results indicated few impurities or substructures resulting from side reactions. The click reaction displayed a high conversion rate, and all the AC-click products demonstrated high solubility in certain solvents. This work provides a facile method for the synthesis of AC in an aqueous system and shows a novel stage for the mild and diverse derivatization of cellulose.
Co-reporter:Feiya Fu, Min Xu, Haoying Wang, Yang Wang, Hao Ge, and Jinping Zhou
ACS Sustainable Chemistry & Engineering 2015 Volume 3(Issue 7) pp:1510
Publication Date(Web):May 19, 2015
DOI:10.1021/acssuschemeng.5b00219
Cellulose carbamates (CCs) were successfully prepared from cellulose/urea (CU) mixtures based on an easy scale-up method and minimum urea. Urea content and the reaction conditions on the nitrogen content of the reacted CU (RCU) mixtures and CCs were systematically investigated. RCU mixtures and CCs were characterized with elemental analysis, Fourier transform infrared spectroscopy, X-ray diffraction, NMR spectrometry and solubility testing. The result indicated that almost all of urea was involved in the derivatization reaction and cellulose was converted into CC with absence of byproducts. The nitrogen content of CCs increased with an increase of the urea content and the reaction temperature, as well as the reaction time. CCs retained the cellulose I crystalline, and the degree of polymerization hardly changed with the reaction conditions. CCs prepared from CU mixtures with the urea content of 3.4–4.6 wt % displayed good solubility in NaOH/ZnO aqueous solutions. Especially, RCU mixtures without washing could be also well dissolved in NaOH/ZnO solutions and its solubility could reach 97%. This work provided a simple, pollution-free and economic pathway for preparing CCs, which is expected to be useful for the CarbaCell process.Keywords: Cellulose carbamate; Conventional heating; Solubility; Structure; Urea
Co-reporter:Baoquan Jia, Yue Dong, Jinping Zhou and Lina Zhang
Journal of Materials Chemistry A 2014 vol. 2(Issue 3) pp:524-529
Publication Date(Web):23 Oct 2013
DOI:10.1039/C3TC31865F
In this work, regenerated cellulose (RC)–Cu nanocomposite films with interesting single-side conductive properties were prepared using in situ coating. The structure and morphology of the films were investigated with XRD, ATR-FTIR, XPS, TG, SEM, TEM and AFM analysis. The mechanical properties and conductive performance of the films were also examined. The copper of a cellulose–cuprammonium solution was employed as the coating source as opposed to the addition of other conductive substances. The single-side coating of Cu nanocomposite film was achieved by one-step reduction based on the asymmetric surface structure of RC film. A layer of Cu nanoparticles with the thickness of ∼1 μm was coated on the coagulant-contacting surface. The RC–Cu nanocomposite films displayed high single-sided conductivity (105.6 ± 63.9 S cm−1). It was found that the resistance could be tuned by changing the bending curvature. This study provides potential applications in areas such as electronic substrates, wearable electronics and sensors.
Co-reporter:Jun You, Chengcheng Zhao, Jinfeng Cao, Jinping Zhou and Lina Zhang
Journal of Materials Chemistry A 2014 vol. 2(Issue 22) pp:8491-8499
Publication Date(Web):24 Mar 2014
DOI:10.1039/C4TA00632A
In this work, we presented an environmentally friendly approach for the immobilization of high-density silver nanoparticles (Ag NPs) on the negatively charged surface of alginate (AL) microspheres. Quaternized cellulose (QC)–Ag nanocomposites are subsequently deposited onto the surface of AL microspheres through the electrostatic interaction between QC and AL. The density of Ag NPs immobilized on the surface of AL microspheres could be altered by varying the Ag content in QC–Ag nanocomposites. Optical microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, transmission electron microscopy and scanning electron microscopy were employed to follow all preparation steps and to characterize the resulting functional surfaces. The catalytic activity of the composite microspheres was evaluated by reduction of p-nitrophenol to p-aminophenol by NaBH4. The results demonstrated that the obtained microspheres exhibited excellent catalytic activity with a high reaction constant of 2.75 min−1. This was a significant enhancement compared to other Ag catalysts reported in the literature.
Co-reporter:Feiya Fu, Quanling Yang, Jinping Zhou, Haoze Hu, Baoquan Jia, and Lina Zhang
ACS Sustainable Chemistry & Engineering 2014 Volume 2(Issue 11) pp:2604
Publication Date(Web):September 17, 2014
DOI:10.1021/sc500559g
In this work, regenerated cellulose (RC) filaments were successfully spun from cellulose carbamate in a NaOH/ZnO aqueous solution on a pilot scale. The structure and properties of the RC filaments were characterized using SEM, FT-IR, elemental analysis, 13C NMR, XRD, 2D WAXD, tensile testing, and dye testing. The nitrogen-free and sulfur-free RC filaments exhibited a bright surface and circular cross section. The filaments demonstrated a typical cellulose II crystal structure and a relatively high degree of orientation. Improved tenacity and structure were obtained in the RC fibers due to improved post-processing spinning steps and an increased drawing ratio. The tenacity of the fibers was determined in the range of 1.69–2.36 cN/dtex, which was comparable with that of commercial viscose rayon. Furthermore, the RC filaments showed improved dye properties compared with viscose rayon. The described carbamate pathway provided a simple and environmentally friendly method, offering an alternate to the environmental drawbacks of the viscose process.Keywords: Cellulose carbamate; Cellulose filaments; Dye properties; Mechanical properties; Orientation
Co-reporter:Feiya Fu, Jinping Zhou, Xuemei Zhou, Lina Zhang, Daoxi Li, and Tetsuo Kondo
ACS Sustainable Chemistry & Engineering 2014 Volume 2(Issue 10) pp:2363
Publication Date(Web):August 18, 2014
DOI:10.1021/sc5003787
In the cellulose industry, the viscose process is still occupying the leading position, although this process generates several environmentally hazardous byproducts. Here we report a novel method for the production of cellulose multifilament from cellulose carbamate (CC) on a pilot scale. In this method, CC was first prepared efficiently by microwave heating; it was then dissolved in NaOH/ZnO aqueous solutions through a freezing–thawing process. Wet spinning of the CC solution was performed on a pilot-scale machine. The cellulose multifilament displayed a dense circular microstructure and excellent physicochemical properties. The tensile strength and elongation at break of the multifilament in dry state were 2.58 cN/dtex and 12.1%, respectively. Moreover, the process could utilize most of the conventional equipment for the viscose method, which could have a great impact on the current cellulose industries.Keywords: Cellulose carbamate; Cellulose multifilament; Fiber-spinning; Microwave-assisted synthesis; NaOH/ZnO aqueous solution;
Co-reporter:Jun You, Lingguo Zhao, Gongwei Wang, Haitao Zhou, Jinping Zhou, Lina Zhang
Journal of Chromatography A 2014 Volume 1343() pp:160-166
Publication Date(Web):23 May 2014
DOI:10.1016/j.chroma.2014.03.079
•Au NPs were synthesized and stabilized by using quaternized cellulose as support matrix.•QC-Au NPs was used as capillary coating for protein separation in capillary electrophoresis.•The separation performance was significantly improved in the capillary coated by QC-Au NPs.•QC-Au NPs provided good resolution for the separation of closely related proteins.Gold nanoparticles (Au NPs) were synthesized and stabilized by using water-soluble quaternized cellulose (QC) as support matrix through a straightforward and environmentally friendly aqueous-phase approach. The structure and morphology of QC-supported Au NPs (QC-Au NPs) were investigated systematically by UV–visible, FT-IR, x-ray diffraction and TEM measurement. The Au NPs with mean diameter of about 7 nm were shown to efficiently redisperse in water due to the strong interaction between QC and Au NPs, and the solutions were quite stable after storage for nearly 4 months at room temperature. QC-Au NPs were subsequently used as novel physically adsorbed coatings for protein separation by CE. The separation performance was significantly improved in the capillary coated by QC-Au NPs compared with that of the uncoated capillary or QC coated capillary. A small quantity of Au NPs (Au content of 4.6%) was adequate for the obvious improvement of coating ability. The theoretical plate number of lysozyme in QC-Au1 NPs coated capillary was 2.9 times as much as that in QC coated capillary. We have demonstrated the separation of six model proteins with RSD of migration time less than 2.79% and RSD of peak area less than 4.81%. Furthermore, QC-Au NPs was applied to the analysis of closely related proteins and biological samples. With simplicity, high resolution and reproducibility, the proposed method shows potential for applications in proteomics and clinical diagnosis.
Co-reporter:Baoquan Jia, Li Yu, Feiya Fu, Lingyan Li, Jinping Zhou and Lina Zhang
RSC Advances 2014 vol. 4(Issue 18) pp:9112-9117
Publication Date(Web):20 Jan 2014
DOI:10.1039/C3RA47031H
A new method for large-scale mimicking of the helical structure of plant tendrils from cellulose solution was proposed based on liquid rope coiling of viscous fluid. In the spinning process, cellulose–cuprammonium solution was extruded from a certain height above a mobile coagulating bath. Helical structure was shown to form spontaneously at the surface of the coagulating bath as a result of buckling instability, and regenerated cellulose helical fiber was obtained after treatment with acid and air-drying. Spinning parameters, such as spinning height, flow rate and moving speed of the coagulating bath were examined in relation to the size and structure of the helical fiber. The microstructure of the helical fiber was further investigated by SEM. The diameters of the fiber and helix were found in the range of 100–400 and 300–700 μm, respectively. The helical fibers demonstrated high elongation at break and elasticity within a certain range of strain, which were attributed to the coiling structure. The microporous feature of the regenerated cellulose helical fiber shows potential as a helical scaffold and template for inorganic materials.
Co-reporter:Lingzhi Zhang, Chengcheng Zhao, Jinping Zhou and Tetsuo Kondo
Journal of Materials Chemistry A 2013 vol. 1(Issue 36) pp:5756-5764
Publication Date(Web):28 Jun 2013
DOI:10.1039/C3TC30689E
Amphiphilic cationic cellulose derivatives with different long alkyl chains as hydrophobic segments were synthesized. They can self-assemble into cationic micelles in distilled water. The structure and properties of the micelles were characterized by elemental analysis, FT-IR, 1H NMR, ζ-potential measurements, DLS, TEM, and fluorescence spectroscopy. The hydrophobic cores of the micelles were used to load a hydrophobic dye (4,7-bis[4-(1,2,2-triphenylvinyl)phenyl]benzo-2,1,3-thiadiazole, BTPETD) and exhibited a stable photoluminescence. The fluorescence emission can quantitatively and sensitively respond to 2,4-dinitrophenol (DNP) and picric acid (PA) due to the electron transfer between BTPETD and the explosives, and the limit of detection was 200 and 50 nM for DNP and PA, respectively. The novel hydrophobically modified cationic cellulose micelles have the potential to prepare feasible, sensitive and stable sensor systems for detecting explosives in aqueous solutions.
Co-reporter:Lingzhi Zhang, Jinping Zhou, Lina Zhang
Carbohydrate Polymers 2013 Volume 94(Issue 1) pp:386-393
Publication Date(Web):15 April 2013
DOI:10.1016/j.carbpol.2012.12.077
β-Cyclodextrin (β-CD)/cellulose hydrogels were prepared in NaOH/urea aqueous solution by crosslinking with epichlorohydrin. The structure and morphology of the hydrogels were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM). The swelling test, 5-fluorouracil (5-FU) and bovine serum albumin (BSA), and aniline blue (AnB) were used to investigate the swelling capability, drug release behavior and the fluorescent property of the hydrogels. The results indicated that the swelling degree and water uptake of the hydrogels decreased with an increase of the β-CD content. The in vitro release of 5-FU and BSA of the hydrogels showed an inclusion complex formed between 5-FU and β-CD. β-CD/cellulose hydrogels adsorbed AnB lead to a fluorescence enhancement attributing to the formation of the host-guest complex between β-CD and AnB.Highlights► β-CD was crosslinked with cellulose in NaOH/urea aqueous solution. ► The swelling degree and water uptake of β-CD/cellulose hydrogels decreased with increasing β-CD content. ► The in vitro release of 5-FU displayed an inclusion complex formed between 5-FU and β-CD. ► Hydrogels contained β-CD could form complex with AnB, and lead to a fluorescence enhancement.
Co-reporter:Jun You, Mengxiong Xiang, Haoze Hu, Jun Cai, Jinping Zhou and Yaping Zhang
RSC Advances 2013 vol. 3(Issue 42) pp:19319-19329
Publication Date(Web):05 Aug 2013
DOI:10.1039/C3RA42242A
This work studied the synthesis and stabilization of silver nanoparticles (Ag NPs) in a quaternized cellulose (QC) aqueous solution. In addition, the catalytic and antibacterial activities, as well as the cytotoxicity of QC–Ag NPs are also examined. The results suggest that QC is an ideal protective agent due to the “electrosteric stabilization” provided by its cationic polymer chains. The prepared QC–Ag nanocomposites show high Ag content (93%) and stability, in addition to good solubility in water. QC–Ag NPs are catalytically active in the reduction of p-nitrophenol to p-aminophenol, and QC is shown to play an important role in the catalytic process, significantly enhancing the catalyst efficiency. On the other hand, the results also show that QC–Ag NPs are nontoxic at concentrations sufficient enough to show good antimicrobial activity.
Co-reporter:Peng Yang, Jun You, Fangping Li, Junjie Fei, Bo Feng, Xiulan He and Jinping Zhou
Analytical Methods 2013 vol. 5(Issue 13) pp:3168-3171
Publication Date(Web):20 May 2013
DOI:10.1039/C3AY40654G
Novel gold nanoparticles (Au@QC NPs), using quaternized cellulose (QC) as the support matrix, were used to entrap hemocyanin (Hc) with the aid of carbon black. Direct electron transfer between Hc and the electrode was achieved and an electrochemical method for the simultaneous detection of hydroquinone and catechol is developed.
Co-reporter:Jun You, Haoze Hu, Jinping Zhou, Lina Zhang, Yaping Zhang, and Tetsuo Kondo
Langmuir 2013 Volume 29(Issue 16) pp:5085-5092
Publication Date(Web):March 25, 2013
DOI:10.1021/la3050913
We provide a highly sensitive and selective assay to detect cysteine (Cys) and Hg2+ in aqueous solutions using Au nanoparticles (NPs) stabilized by carboxylethyl quaternized cellulose (CEQC). This method is based on the thiophilicity of Hg2+ and Au NPs as well as the unique optical properties of CEQC-stabilized Au NPs. CEQC chains are good stabilizing agents for Au NPs even in a high-salt solution. The addition of Cys results in the aggregation of CEQC-stabilized Au NPs, which induces the visible color change and obvious redshift in UV–visible absorption spectra. On the other hand, Hg2+ is more apt to interact with thiols than Au NPs; thus, it can remove the Cys and trigger Au NP aggregate redispersion again. By taking advantage of this mechanism, a novel off–on colorimetric sensor has been established for Cys and Hg2+ detection. This new assay could selectively detect Cys and Hg2+ with the detection limits as low as 20 and 40 nM in aqueous solutions, respectively.
Co-reporter:Jun You;Haoze Hu
Cellulose 2013 Volume 20( Issue 3) pp:1175-1185
Publication Date(Web):2013 June
DOI:10.1007/s10570-013-9891-9
A novel cellulose-based polyampholyte derivative, carboxylethyl quaternized cellulose (CEQC), was homogeneously synthesized by introducing positively charged quaternary ammonium groups and negatively charged carboxyl groups to the backbone of cellulose. The structure and dilute solution properties of CEQCs were characterized with elemental analysis, FTIR, NMR, viscometer, light scattering and zeta-potential measurement. The nitrogen content and total degree of substituent of acylamino and carboxyl groups increased with an increase of the molar ratio of acrylamide to the anhydroglucose unit of quaternized cellulose (QC). The salt-resistance of CEQC was improved remarkably by introducing opposite charged carboxyl to the QC chains. The intrinsic viscosity of the prepared polyampholytes was found to be very sensitive to the pH of the solutions. CEQC-1, the sample with relative low content of carboxyl groups, behaved as a classical cationic polyelectrolyte. However, CEQC-2 and CEQC-3, the samples with higher content of carboxyl groups, displayed typical polyampholyte behavior, and the isoelectric points (IEP) were determined to be 5.0 and 3.8 respectively. This work provided a facile method for the synthesis of novel cellulose-based polyampholytes with different IEP.
Co-reporter:Lingzhi Zhang;Lina Zhang
Cellulose 2013 Volume 20( Issue 1) pp:105-114
Publication Date(Web):2013 February
DOI:10.1007/s10570-012-9813-2
Fluorescent-labeled polymers, carbazole-substituted methylcelluloses (Cz-MCs) were synthesized through a two-step reaction by firstly introducing epoxy group to carbazole, and then reacting with MC. Structure of Cz-MC was characterized by using FTIR, NMR, elemental analysis and UV–vis spectroscopy. Aggregation behavior of Cz-MCs in dilute aqueous solution was investigated by a thermotropic study performed with dynamic laser light scattering. Cz-MCs displayed concentration self-quenching properties of fluorescence spectra both in H2O and DMSO. The temperature effect on the fluorescent emission in dilute aqueous solution was explored. The results showed that the degree of substitution of carbazole and thermal aggregation of Cz-MC contributed to the formation of network structure between the molecules, consequently leading to the enhancement or quenching in fluorescence intensity.
Co-reporter:Baoquan Jia, Yan Mei, Li Cheng, Jinping Zhou, and Lina Zhang
ACS Applied Materials & Interfaces 2012 Volume 4(Issue 6) pp:2897
Publication Date(Web):June 8, 2012
DOI:10.1021/am3007609
Regenerated cellulose (RC) films coated with copper (Cu) nanoparticles were prepared from cellulose-cuprammonium solution through coagulation in aq. NaOH and subsequent reduction in aq. NaBH4. Structure and morphology of the nanocomposite films were characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The results established the migration of Cu2+ from the inner to the surface of the RC films during the coagulation of cellulose-cuprammonium solution and the reduction from Cu2+ to Cu0. Cu nanoparticles were found to be firmly embedded on the surface of the RC films. The RC films coated with Cu nanoparticles showed efficient antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The dramatic reduction of viable bacteria could be observed within 0.5 h of exposure, and all of the bacteria were killed within 1 h.Keywords: antibacterial; cellulose; copper nanoparticles; nanocomposite film; one-step reduction;
Co-reporter:Lingzhi Zhang;Qian Li;Lina Zhang
Macromolecular Chemistry and Physics 2012 Volume 213( Issue 15) pp:1612-1617
Publication Date(Web):
DOI:10.1002/macp.201200233
Abstract
Cellulose nanocrystals are converted into fluorescent labeling nanoparticles (Py-CNC) by a three-step procedure. The fluorescence emission of pyrene is enhanced after the modification to cellulose nanocrystals. Py-CNC is evaluated for its sensing ability towards metal ions and exhibits high selectivity towards Fe3+ among other screened metal ions with good discrimination between Fe2+ and Fe3+. The excellent selectivity for Fe3+ over a wide linear concentration range is observed through changes in the emission spectra. Spectroscopic analyses prove that the coordination interaction between Fe3+ and pyrene-modified cellulose nanocrystals leads to the recognition process. This sensing nanomaterial can be employed as a chemosensor for Fe3+ and promoted for many applications in chemical, environmental, and biological systems.
Co-reporter:Fei Ding;Jun You;Xiaocheng Weng;Xiaolian Zhang;Xiang Zhou;Lina Zhang
Chinese Journal of Chemistry 2012 Volume 30( Issue 9) pp:2212-2218
Publication Date(Web):
DOI:10.1002/cjoc.201200659
Abstract
Cationic polysaccharides have been receiving more attentions and used as nonviral gene delivery vectors. In this paper, quaternized hydroxyethylcellulose (QHEC) derivatives were studied as gene carriers for their efficient DNA binding abilities. All QHECs could form stable QHEC/DNA complexes and resist the degradation of DNase I. And the dynamic light scatter (DLS) results showed that all QHEC/DNA complexes could form compact particles. These QHEC/DNA complexes exhibited effective transfection abilities in comparison to the naked DNA. The cytotoxicities of QHEC and QHEC/DNA complexes were also evaluated in four cell lines which were relatively low compared with 25 kDa bPEI. All results indicated that these quaternized hydroxyethylcelluloses could be used as potential gene delivery vectors.
Co-reporter:Lingzhi Zhang;Lina Zhang
Macromolecular Chemistry and Physics 2012 Volume 213( Issue 1) pp:57-63
Publication Date(Web):
DOI:10.1002/macp.201100484
Abstract
Carbazole-substituted hydroxyethylcelluloses (Cz-HECs) are homogeneously synthesized by reacting hydroxyethylcellulose (HEC) with N-3′-bromopropyl carbazole (Br-Cz). The structure of Cz-HECs is characterized with elemental analysis and NMR, and the DS of the carbazole is in the range 0.11–0.43, determined from nitrogen content. The fluorescent properties of Cz-HECs are measured using a spectrofluorimeter. The results show that the fluorescence lifetime increases as the DS increases, and the fluorescent intensity of Cz-HECs is stronger than that of Br-Cz. All samples exhibit concentration self-quenching properties. The addition of acrylonitrile, as an electron acceptor, quenches the emission spectra of Cz-HECs, and the fluorescence quenching is found to be a dynamic quenching by analyzing with the Stern–Volmer equation.
Co-reporter:Qian Li;Pingjian Wu;Lina Zhang
Cellulose 2012 Volume 19( Issue 1) pp:161-169
Publication Date(Web):2012 February
DOI:10.1007/s10570-011-9609-9
Cyanoethyl celluloses (CECs) with different degree of substitution (DS) were synthesized by homogeneous reaction of cellulose (cotton linter pulp and absorbent cotton) with acrylonitrile (AN) in LiOH/urea aqueous solutions. The reaction showed quick reactivity and high transfer efficiency of etherification agent. The DS values of CECs were controlled by varying the molar ratio of AN to anhydroglucose unit (AGU) and the cellulose concentration. The DS values of the CEC-1–CEC-10 increased from 0.27 to 1.78 with increasing molar ratio of AN to AGU from 0.5:1 to 9:1. While the CEC-11–CEC-21 with DS values of 0.26–1.81 could be obtained by adjusting the molar ratio from 1:1 to 27:1. The relative reactivity of hydroxyl groups is in the order of C-6 > C-2 > C-3. The DS values of the water-soluble derivatives are in the range of 0.47–1.01. As the DS values increase to 1.37, CEC samples can not be dissolved in water or dilute alkali solution, but have good solubility in organic solvents, such as DMSO, DMF and pyridine. The dilute solution properties and molecular parameters of the CEC samples were studied by static light scattering and dynamic light scattering. The results indicated that the water-soluble samples could form a small number of aggregates spontaneously in 0.9 wt% NaCl aqueous solution, while the water-insoluble samples showed extended stiff chains in 0.5% LiCl–DMAc.
Co-reporter:Zhiwei Jiang;Ang Lu;Lina Zhang
Cellulose 2012 Volume 19( Issue 3) pp:671-678
Publication Date(Web):2012 June
DOI:10.1007/s10570-012-9669-5
To clarify the interaction between the –OH groups of cellulose and NaOH/urea in aqueous solutions, methylcellulose (MC) was used as solute to study its solution properties at low temperature. Dynamic light scattering, 13C NMR spectroscopy, differential scanning calorimetry, and transmission electron microscopy (TEM) were used to characterize the MC macromolecular size and intermolecular interactions between MC and solvent molecules. The results revealed that MC existed mainly as individual molecules in the NaOH/urea aqueous solution prepared by freeze-thawing process, whereas aggregates occurred in the MC solution prepared at room temperature. DLS further confirmed that MC existed mainly as individual flexible chains in the solution treated at low temperature. TEM images showed the sphere-like coil appearance of the MC macromolecules in the solution prepared at low temperature. Therefore, the strong interaction between –OH groups of MC and solvent occurred at low temperature, leading to the formation of the imperfect inclusion complex through hydrogen bonding network between MC, NaOH, urea and water.
Co-reporter:Qian Li;Lina Zhang
Cellulose 2012 Volume 19( Issue 5) pp:1547-1555
Publication Date(Web):2012 October
DOI:10.1007/s10570-012-9739-8
Water-soluble cyanoethyl cellulose (CEC) samples were synthesized by homogeneous reaction of cellulose with acrylonitrile in LiOH/urea aqueous solutions. The dynamic viscoelastic property of CEC with different degree of substitution (DS) in water at different temperatures and concentrations were investigated. At low concentrations, the CEC solutions displayed liquid-like behavior with G′ smaller than G′′ at low frequencies; while the curves of G′ and G′′ intersected at the middle of the frequency range at higher concentration, indicating an existence of chain aggregation and entanglement network. The gelation temperature (Tgel) was determined from the point of intersection in tan δ versus temperature (T) at different frequencies, indicating the validity of Winter–Chambon criteria. It was found that Tgel increased with increasing DS, and that the exponent (n) values at the gel point decreased with increasing DS. The heating–cooling process proved that the sol–gel transition for CECs in water was thermally irreversible. The AFM images revealed that the particles packed loosely together to form gel aggregates. Moreover, the Maxwell model with four elements was used to describe the frequency dependencies of G′ and G′′ for CEC in aqueous solution.
Co-reporter:Ming Li, Ying Qi, Yonglan Ding, Qinglan Zhao, Junjie Fei, Jinping Zhou
Sensors and Actuators B: Chemical 2012 Volume 168() pp:329-335
Publication Date(Web):20 June 2012
DOI:10.1016/j.snb.2012.04.030
Quaternized cellulose nanoparticles (QCs)/acetylene black (AB)/enzymes composite electrodes, constructed by simple physical inclusion of the enzyme into the bulk of the electrode matrix, have been used for the amperometric detection of hydrogen peroxide (H2O2) and glucose. The new composite material combines the unique and attractive electrocatalytic behaviors of QCs and acetylene black, with excellent biocompatible, electric conductivity and large specific surface area. The modified electrodes were electrochemically characterized, and bioelectrocatalytic reactions were followed. The resulting composite film promotes the direct electron transfer of GOD and Hb immobilized in the films effectively with fast electron transfer rates. The prepared enzyme/QCs-AB composite film exhibited high electrocatalytic performance to hydrogen peroxide (H2O2) and glucose, with fast response, wide linear range, good sensitivity and excellent stability. The successful practice of using the QCs-AB modified electrode for the direct electrochemistry and bioelectrocatalytic activity of enzymes offers an efficient strategy and a new promising platform for the construction of unmediated enzyme biosensors.
Co-reporter:Jun You, Jinping Zhou, Qian Li, and Lina Zhang
Langmuir 2012 Volume 28(Issue 11) pp:4965-4973
Publication Date(Web):February 23, 2012
DOI:10.1021/la2046417
As a weak base, β-glycerophosphate (β-GP) was used to spontaneously initiate gelation of quaternized cellulose (QC) solutions at body temperature. The QC/β-GP solutions are flowable below or at room temperature but gel rapidly under physiological conditions. In order to clarify the sol–gel transition process of the QC/β-GP systems, the complex was investigated by dynamic viscoelastic measurements. The shear storage modulus (G′) and loss modulus (G″) as a function of (1) concentration of β-GP (cβ-GP), (2) concentration of QC (cQC), (3) degree of substitution (DS; i.e., the average number of substituted hydroxyl groups in the anhydroglucose unit) of QC, (4) viscosity-average molecular weight (Mη) of QC, and (5) solvent medium were studied by the oscillatory rheology. The sol–gel transition temperature of QC/β-GP solutions decreased with an increase of cQC and cβ-GP, the Mη of QC, and a decrease of the DS of QC and pH of the solvent. The sol–gel transition temperature and time could be easily controlled by adjusting the concentrations of QC and β-GP, Mη and DS of QC, and the solvent medium. Gels formed after heating were irreversible; i.e., after cooling to lower temperature they could not be dissolved to become liquid again. The aggregation and entanglement of QC chains, electrostatic interaction, and hydrogen bonding between QC and β-GP were the main factors responsible for the irreversible sol–gel transition behavior of QC/β-GP systems.
Co-reporter:Yongbo Song, Weiping Gan, Qian Li, Yi Guo, Jinping Zhou, Lina Zhang
Carbohydrate Polymers 2011 Volume 86(Issue 1) pp:171-176
Publication Date(Web):1 August 2011
DOI:10.1016/j.carbpol.2011.04.025
By controlling the saponification hydrolysis of acylamino groups to carboxyl groups in alkaline medium, a series of acrylamide-modified cellulose polyelectrolyte (AMC) samples with various degree of hydrolysis (DH) were successfully obtained. The structure and solution properties of AMC were characterized by using elemental analysis, FT-IR, 13C NMR, viscometer, and zeta potential measurement. The results revealed that DH value of AMC samples could be controlled by adjusting the hydrolysis reaction time. The carboxyl group content and intrinsic viscosity ([η]) value increased with increasing DH value. Moreover, ferric hydroxide (Fe(OH)3) colloid was selected as a model to evaluate the flocculation properties of AMC. The results showed that AMC was an effective flocculant to Fe(OH)3 colloid, and the Fe(OH)3 colloid was almost removed (up to nearly 100%). Therefore, acrylamide-modified celluloses are applicable as novel flocculants with high flocculation efficiency, non-toxicity as well as biodegradability.
Co-reporter:Baoquan Jia, Jinping Zhou, Lina Zhang
Carbohydrate Research 2011 Volume 346(Issue 11) pp:1337-1341
Publication Date(Web):16 August 2011
DOI:10.1016/j.carres.2011.04.040
Nano-fibrous mats have been successfully prepared by electrospinning of the blend solutions of cationic cellulose derivatives (PQ-4) and polyvinyl alcohol (PVA). Effects of the blending ratio and applied voltage on the morphology and diameter of the electrospun nano-fibers were investigated. The average diameter of the PQ-4/PVA blend fibers was in the range of 150–250 nm. The electrospinning process became instable and the fiber diameter distribution broadened with increasing PQ-4 content and applied voltage. The antibacterial activity of electrospun PQ-4/PVA blend mats against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus indicated potential for biomedical use.
Co-reporter:Shilin Liu;Haoze Hu;Lina Zhang
Cellulose 2011 Volume 18( Issue 5) pp:1273-1283
Publication Date(Web):2011 October
DOI:10.1007/s10570-011-9566-3
Magnetic Co3O4 nanoparticles were prepared by using microporous regenerated cellulose films as sacrificial scaffolds. The cellulose macromolecules and the porous structure of the films made them used as spatially confined reacting sites where Co(OH)2 nanoparticles could be synthesized in situ. When the cellulose matrix was removed by sintering at 500 °C, Co3O4 nanoparticles were obtained. XRD and XPS indicated that the prepared nanoparticles were pure Co3O4 without any impurity. TEM and SEM images revealed that the particle size of the nanoparticles was smaller than 100 nm. The nanoparticles had weak ferromagnetic properties at 25 °C. Furthermore, the pronounced quantum confinement effects of the synthesized nanoparticles have been observed, the optical bandgap energies determined were about 1.92 ~ 2.12 and 2.74 ~ 2.76 eV for O2− → Co3+ and O2− → Co2+ charge-transfer processes, respectively. Furthermore, the resulted Co3O4 nanoparticles behaved stable electrochemical performance with promising applications in the electrode for lithium ion battery.
Co-reporter:Yi Guo, Jinping Zhou, and Lina Zhang
Biomacromolecules 2011 Volume 12(Issue 5) pp:
Publication Date(Web):April 8, 2011
DOI:10.1021/bm200331g
Dynamic viscoelastic properties of cellulose carbamate (CC) dissolved in NaOH aqueous solution were systematically studied for the first time. CC was microwave-assisted synthesized from the mixture of cellulose and urea and then dissolved in 7 wt % NaOH aqueous solution precooled to −7 °C. The obtained CC solution is transparent and has good liquidity. To clarify the rheological behavior of the solution, the CC solutions were investigated by dynamic viscoelastic measurements. The shear storage modulus (G′) and loss modulus (G′′) as a function of the angular frequency (ω), concentration (c), nitrogen content (N %), viscosity-average molecular weight (Mη), temperature (T), and time (t) were analyzed and discussed in detail. The sol–gel transition temperature of CC (Mη = 7.78 × 104) solution decreased from 36.5 to 31.3 °C with an increase of the concentration from 3.0 to 4.3 wt % and decreased from 35.7 to 27.5 °C with an increase of the nitrogen content from 1.718 to 5.878%. The gelation temperature of a 3.8 wt % CC solution dropped from 38.2 to 34.4 °C with the Mη of CC increased from 6.35 × 104 to 9.56 × 104. The gelation time of the CC solution was relatively short at 30 °C, but the solution was stable for a long time at about 15 °C. Moreover, the gels already formed at elevated temperature were irreversible; that is, after cooling to a lower temperature including the dissolution temperature (−7 °C), they could not be dissolved to become liquid.
Co-reporter:Yongbo Song, Lingzhi Zhang, Weiping Gan, Jinping Zhou, Lina Zhang
Colloids and Surfaces B: Biointerfaces 2011 Volume 83(Issue 2) pp:313-320
Publication Date(Web):1 April 2011
DOI:10.1016/j.colsurfb.2010.11.039
Novel amphiphilic cationic cellulose (HMQC) derivatives carrying long chain alkyl groups as hydrophobic moieties and quaternary ammonium groups as hydrophilic moieties were synthesized. Structure and properties of the amphiphilic cellulose derivatives were characterized by elemental analysis, FT-IR, 1H NMR, ζ-potential measurement, dynamic light scattering (DLS), fluorescence spectroscopy and transmission electron microscopy (TEM). The results revealed that HMQCs can be self-assembled into cationic micelles in distilled water with the average hydrodynamic radius of 320–430 nm. The cytotoxicity study showed that the HMQC exhibited low cytotoxicity. Prednisone acetate, a water insoluble anti-inflammation drug, was chosen as a model drug to investigate the utilization of self-assembled HMQC micelles as a delivery carrier for poorly water-soluble drugs. The study indicated that the prednisone acetate could be incorporated effectively in the self-assembled HMQC micelles and be controlled released.Graphical abstractHydrophobically modified quaternized cellulose (HMQC) can self-assemble into cationic polymeric micelles in aqueous medium, and prednisone acetate can be incorporated effectively in the self-assembled HMQC micelles and be controlled released.Research highlights▶ Novel amphiphilic cationic cellulose derivatives (HMQC) were synthesized. ▶ Chemical structure and physicochemical properties of HMQC have been studied. ▶ HMQC can self-assemble into micelles in aqueous medium. ▶ Prednisone acetate can be incorporated in the micelles and be controlled released.
Co-reporter:Shilin Liu ; Jinping Zhou ;Lina Zhang
The Journal of Physical Chemistry C 2011 Volume 115(Issue 9) pp:3602-3611
Publication Date(Web):February 16, 2011
DOI:10.1021/jp111263p
Plate-like Fe2O3 nanoparticles were prepared in microporous regenerated cellulose films and then completely removed from the cellulose matrix by calcination. Crystallite size and properties variations of the nanosized Fe2O3 during γ- to α-phase transformation were investigated. The γ-Fe2O3 nanoparticles with an initial particle size of 24 nm increased from 26 to 83 nm with an increase of the calcination temperature from 350 to 800 °C, and the phase transformation temperature was about 500 °C. The nanoparticles made at 350 and 450 °C exhibited superparamagnetic properties with the corresponding blocking temperature (TB) of about 83 and 80 K. The nanoparticles made at 500, 600, and 700 °C not only exhibited Curie transitions with TB's of about 77, 54, and 15 K but also had Morin transitions from a pure antiferromagnet to a ferromagnet occurring at about 238, 240, and 246 K, respectively. However, the nanoparticles made at 800 °C only gave a clear Morin transition from a pure antiferromagnet to a ferromagnet at about 250 K. Furthermore, the nanoparticles also displayed different electrochemical properties.
Co-reporter:Jinping Zhou, Qian Li, Yongbo Song, Lina Zhang and Xiaoyan Lin
Polymer Chemistry 2010 vol. 1(Issue 10) pp:1662-1668
Publication Date(Web):06 Sep 2010
DOI:10.1039/C0PY00163E
A series of cyanoethyl cellulose (CEC) samples were synthesized from cellulose in NaOH/urea aqueous solutions by a homogeneous method. Structure and properties of CECs were characterized with FT-IR, 1H and 13C NMR, DSC, SEC-LLS, polarized light microscopy and solubility measurements. The total DS values of the obtained CECs were in the range of 0.26 to 1.93, and the relative reactivity of hydroxyl groups is in the order C-6 > C-2 > C-3. As the molar ratio of acrylonitrile to anhydroglucose unit (AGU) of cellulose increased to 5:1, the C-6 hydroxyl groups of AGU were fully substituted. The total DS value for water-soluble CEC is as low as 0.54. CEC could be dissolved in many organic solvents when its total DS value reached 1.37. Organic-soluble CEC samples displayed thermotropic liquid crystalline behavior in the temperature range of 180 to 280 °C. Moreover, NaOH/urea aqueous solution was proved to be a stable medium for cyanoethylation of cellulose, the reaction products could be easy isolated and purified, and the solvents could be recycled by a simple filtration. Therefore, this work provides a facile method for the homogeneous synthesis of CEC in an aqueous system.
Co-reporter:Yongbo Song, Huiyuan Wang, Xuan Zeng, Yunxia Sun, Xianzheng Zhang, Jinping Zhou and Lina Zhang
Bioconjugate Chemistry 2010 Volume 21(Issue 7) pp:1271
Publication Date(Web):June 3, 2010
DOI:10.1021/bc100068f
Quaternized celluloses (QCs) with different molecular weight (Mw) and degree of cationic substitution (DS) were homogeneously synthesized in NaOH/urea aqueous solutions and were studied as gene carriers. QCs were evaluated for efficacy of nanoparticle formation, DNA binding efficiency, morphology, and in vitro gene transfection efficiency. The factors affecting the transfection efficiency, e.g., Mw, DS, and N/P ratios, have been evaluated. The cytotoxicity of QCs and QC/DNA complexes were evaluated in 293T cells and were found to be relatively low compared with 25 kDa PEI and PEI/DNA complex, which increased slightly with increasing of Mw and DS. All QCs obtained could bind DNA efficiently, and QC/DNA complexes exhibited effective transfection in comparison to the naked DNA. More importantly, the QC/DNA complexes, were stable and the transfection efficiency was not inhibited in the presence of serum. The results revealed an important combined effect between Mw and DS of QCs in determining transgene expression, and QCs with Mw of about 8 × 104 g/mol and DS of about 0.6 displayed relatively higher transfection efficiencies attributed to the intermediate stability.
Co-reporter:Chunyu Chang, Lingzhi Zhang, Jinping Zhou, Lina Zhang, John F. Kennedy
Carbohydrate Polymers 2010 Volume 82(Issue 1) pp:122-127
Publication Date(Web):2 August 2010
DOI:10.1016/j.carbpol.2010.04.033
Hydrogels have been successfully prepared from cellulose in NaOH/urea aqueous solution by using epichlorohydrin (ECH) as a cross-linker, and via heating and freezing methods. Structure and properties of the hydrogels were measured with UV–vis spectroscopy, SEM, XRD, solid-state 13C NMR, rheometry and water absorption testing. The results indicated that hydrogels prepared by heating displayed macroporous inner structure, while fiber-like structure could be observed in the hydrogels prepared by freezing. The light transparency and equilibrium swelling ratio of the hydrogels decreased, while the reswelling water uptake and the storage modulus increased, with an increase of the cellulose content. Compared with the hydrogels post-treated by freezing, the hydrogels prepared by heating displayed better light transmittance, higher equilibrium swelling ratios and reswelling water uptakes, and relatively weaker mechanical strength. Therefore, the structure and properties of the hydrogels could be adjusted by changing the cellulose content and the post-treatment methods.
Co-reporter:Yongbo Song, Jie Zhang, Weiping Gan, Jinping Zhou and Lina Zhang
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 3) pp:1242-1246
Publication Date(Web):December 28, 2009
DOI:10.1021/ie9015057
Three water-soluble quaternized cellulose derivatives (QCs) with degree of substitution (DS) values of 0.38, 0.50, and 0.74 were synthesized in NaOH/urea aqueous solutions. The flocculation characteristics of QCs have been evaluated in montmorillonite (MMT) suspensions and simulated dye (Reactive Red) aqueous solutions by spectrophotometry. The results showed that QCs were effective flocculating agents for MMT over a wide range of pH values, and the flocculation efficiency of MMT was up to nearly 100%. Decolorization efficiency of Reactive Red dye reached 93% under optimum conditions. In vitro antimicrobial activity of QC was evaluated by determining minimum inhibition concentration (MIC) values against Gram-positive bacteria (S. aureus) and Gram-negative bacteria (E. coli), respectively. The results showed that QC could strongly inhibit the growth of E. coli and S. aureus. Therefore, quaternized cellulose is applicable as a novel wastewater treatment agent with high flocculation efficiency as well as effective antimicrobial activity.
Co-reporter:Yi Guo;Yuchen Wang;Lina Zhang;Xiaoyan Lin
Cellulose 2010 Volume 17( Issue 6) pp:1115-1125
Publication Date(Web):2010 December
DOI:10.1007/s10570-010-9446-2
Cellulose carbamates (CCs) were microwave-assisted synthesized from the native cellulose and urea under solvent-free and catalyst-free conditions. Types of raw materials, the effects of the reaction condition on the nitrogen content of CCs were investigated. CCs were characterized with infrared spectroscopy (FT-IR), 13C NMR spectrometry, X-ray diffraction, scanning electron microscopy and thermogravimetry. The results indicated that various source of native celluloses such as cotton linter, reed, bagasse and wood pulps with different degree of polymerization could be successfully converted to CCs by the efficient and environmentally friendly procedure. The nitrogen content of CCs increased with an increase of the urea content and the mass of the mixtures, as well as the pulsed times of microwave irradiation. CCs retained the cellulose I crystalline form of the native cellulose and the degree of crystallinity decreased with the incorporation of carbamates. This work provided a novel pathway for the preparation of cellulose carbamate, which is expected to be useful for the CarbaCell process.
Co-reporter:Yi Guo;Yongbo Song ;Lina Zhang
Macromolecular Rapid Communications 2009 Volume 30( Issue 17) pp:1504-1508
Publication Date(Web):
DOI:10.1002/marc.200900238
Co-reporter:Yongbo Song;Qian Li;Yi Guo ;Lina Zhang
Macromolecular Bioscience 2009 Volume 9( Issue 9) pp:857-863
Publication Date(Web):
DOI:10.1002/mabi.200800371
Co-reporter:Jinping Zhou;Ran Li;Shilin Liu;Qian Li;Linzhi Zhang;Lina Zhang;Jianguo Guan
Journal of Applied Polymer Science 2009 Volume 111( Issue 5) pp:2477-2484
Publication Date(Web):
DOI:10.1002/app.29236
Abstract
Cellulose nanocomposites containing high contents of Fe3O4 nanoparticles were successfully prepared with regenerated cellulose films as a matrix and mixture solutions of Fe2+/Fe3+ as precursors. The structure and properties of the magnetic nanocomposite films were investigated with X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and vibrating sample magnetometry. Fe3O4 nanoparticles as prepared were irregular spheres and were homogeneously dispersed in the cellulose matrix. With an increase in the concentration of precursors from 0.2 to 1.0 mol/L, the content of Fe3O4 nanoparticles in the dried nanocomposites increased from 12 to 39 wt %, and the particle diameter increased from 32 to 64 nm. The cellulose nanocomposite films demonstrated superparamagnetic behavior, and their saturation magnetizations were in the range 4.2–21.2 emu/g, which were related to the increase in Fe3O4 nanoparticle content. With increasing nanophase content, the nanocomposite films displayed significantly anisotropic magnetic properties in the parallel and perpendicular directions. This study provided a green and facile method for the preparation of biobased nanocomposite films with high nanophase content and excellent magnetic properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Co-reporter:Yongbo Song, Jinping Zhou, Qian Li, Ang Lue, Lina Zhang
Carbohydrate Research 2009 Volume 344(Issue 11) pp:1332-1339
Publication Date(Web):27 July 2009
DOI:10.1016/j.carres.2009.04.023
A novel cellulose-based polyelectrolyte (AM-C) containing acylamino (DS = 0.625) and carboxyl (DS = 0.148) groups was homogeneously synthesized from cellulose with acrylamide in NaOH/urea aqueous solutions. Solution properties of AM-C in aqueous solutions were investigated by laser light scattering, rheometry, and viscometry. The results indicated that AM-C could form large aggregates spontaneously in water with or without the addition of salts by the strong hydrogen bonds and electrostatic interaction between acylamino and carboxyl groups. Steady-shear flow study showed a Newtonian behavior of the solutions in the dilute regime while a shear-thinning behavior as the concentration increases. The critical concentration (ce) for transition from dilute to concentrated solution was determined to be 0.7 wt %. Aqueous solutions of AM-C displayed good thermo-stability, reversible liquid-like characters attributing to the chemical modification. The derivation from Cox–Merz rule at relatively low concentration was related to the co-existence of single chain and large aggregates of AM-C in dilute regime. As the polymer concentration increased, the AM-C system was transformed into a homogeneous entanglement structure, resulting in the disappearance of deviations from the Cox–Merz rule.
Co-reporter:Shanshan Jia, Junjie Fei, Jinping Zhou, Xiaoming Chen, Jianqiang Meng
Biosensors and Bioelectronics 2009 Volume 24(Issue 10) pp:3049-3054
Publication Date(Web):15 June 2009
DOI:10.1016/j.bios.2009.03.022
A water-soluble cyanoethyl cellulose (CEC), homogeneously synthesized in NaOH/urea aqueous solution, was used as an immobilization matrix to entrap proteins and enzymes. Then hemoglobin (Hb) was used as a template to fabricate CEC–Hb biomimetic membranes in which the Hb showed direct electrochemistry on a glass carbon electrode (GCE). The characterizations of CEC–Hb film were demonstrated by ultraviolet–visible (UV–vis) spectra, scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of Hb in CEC film have been investigated and a pair of well-defined and quasi-reversible cyclic voltammetric peaks for the protein heme Fe(III)/Fe(II) redox couples was observed at about −0.369 V (vs. SCE). The CEC–Hb film exhibited a good electrocatalytic activity for the reduction of nitric oxide (NO). The amperometric response of the biosensor varied linearly with the NO concentration ranging from 1.1 × 10−6 to 1.3 × 10−4 mol L−1. Moreover, the studied biosensor exhibited high sensibility, good reproducibility, and long-term stability. Finally, this method has applied to monitoring the NO release from biologic samples.
Co-reporter:Qian Li;Lina Zhang
Journal of Polymer Science Part B: Polymer Physics 2009 Volume 47( Issue 11) pp:1069-1077
Publication Date(Web):
DOI:10.1002/polb.21711
Abstract
Bio-based nanocomposite films were successfully developed using cellulose whiskers as the reinforcing phase and chitosan as the matrix. Cellulose whiskers, with the lengths of 400 ± 92 nm and diameters of 24 ± 7.5 nm on average, were prepared by hydrolyzing cotton linter with sulfuric acid solution. The effects of whisker content on the structure, morphology and properties of the nanocomposite films were characterized by SEM, XRD, FTIR, UV-vis spectroscopy, DMA, TG, tensile testing, and swelling experiment. The results indicated that the nanocomposites exhibited good miscibility, and strong interactions occurred between the whiskers and the matrix. With increasing whisker content from 0 to 15–20 wt %, the tensile strength of the composite films in dry and wet states increased from 85 to 120 MPa and 9.9 to 17.3 MPa, respectively. Furthermore, the nanocomposite films displayed excellent thermal stability and water resistance with the incorporation of cellulose whiskers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1069–1077, 2009
Co-reporter:Yongbo Song, Yunxia Sun, Xianzheng Zhang, Jinping Zhou and Lina Zhang
Biomacromolecules 2008 Volume 9(Issue 8) pp:
Publication Date(Web):July 19, 2008
DOI:10.1021/bm800429a
Quaternized celluloses (QCs) were homogeneously synthesized by reacting cellulose with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) in NaOH/urea aqueous solutions. The structure and solution properties of the QCs were characterized by using elemental analysis, FTIR, 13C NMR, SEC-LLS, viscometer, and ζ-potential measurement. The results revealed that water-soluble QCs, with a degree of substitution (DS) value of 0.20−0.63, could be obtained by adjusting the molar ratio of CHPTAC to anhydroglucose unit (AGU) of cellulose and the reaction time. The QC solutions in water displayed a typical polyelectrolyte behavior, and the intrinsic viscosity ([η]) value determined from the Fuoss−Strauss method increased with increasing DS value. Moreover, two QC samples (DS = 0.46 and 0.63) were selected and studied as gene carriers. The results of gel retardation assay suggested that QCs could condense DNA efficiently. QCs displayed relatively lower cytotoxicity as compared with PEI, and QC/DNA complexes exhibited effective transfection compared to the naked DNA in 293T cells. The quaternized cellulose derivatives prepared in NaOH/urea aqueous solutions could be considered as promising nonviral gene carriers.
Co-reporter:Jinping Zhou;Chunyu Chang;Ruping Zhang;Lina Zhang
Macromolecular Bioscience 2007 Volume 7(Issue 6) pp:804-809
Publication Date(Web):31 MAY 2007
DOI:10.1002/mabi.200700007
Novel cellulose hydrogels were synthesized through a “one-step” method from cellulose, which was dissolved directly in NaOH/urea aqueous solution, by using epichlorohydrin as crosslinker. Structure and properties of the hydrogels were characterized by using SEM, NMR, and water absorption testing. The hydrogels are fully transparent and display macroporous inner structure. The equilibrium swelling ratios of the hydrogels in distilled water at 25 °C are in the range from 30 to 60 g H2O/g dry hydrogel. Moreover, the reswelling water uptake of the hydrogels could be achieved to more than 70% compared with their initial swelling states. This work provided a simple and fast method for preparing eco-friendly hydrogels from unsubstituted cellulose.
Co-reporter:Lina Zhang;Jianbo Wang;Jianguo Guan;Shilin Liu
Macromolecular Rapid Communications 2006 Volume 27(Issue 24) pp:2084-2089
Publication Date(Web):1 DEC 2006
DOI:10.1002/marc.200600543
Summary: A polymer-iron oxide nanocomposite film has been successfully synthesized by using a microporous regenerated cellulose film as template and aqueous ferrous chloride as precursor. The nanocomposite film was investigated with XRD, XPS, SEM, TEM, and VSM. The nanoparticles synthesized in situ were disk-shaped with a mean diameter of ≈24 and thicknesses of 2.5–3.5 nm. For the first time, the nanodisks were well aligned in the cellulose matrix to form an ordered multibilayer structure by the shrinkage of the hybrid film while drying. The nanocomposite film displayed anisotropic magnetic properties as a result of the alignment of magnetic nanodisks. This work provides a novel and facile method for template synthesis of nanoparticles and aligned nanocomposites.
Co-reporter:Jun You, Chengcheng Zhao, Jinfeng Cao, Jinping Zhou and Lina Zhang
Journal of Materials Chemistry A 2014 - vol. 2(Issue 22) pp:NaN8499-8499
Publication Date(Web):2014/03/24
DOI:10.1039/C4TA00632A
In this work, we presented an environmentally friendly approach for the immobilization of high-density silver nanoparticles (Ag NPs) on the negatively charged surface of alginate (AL) microspheres. Quaternized cellulose (QC)–Ag nanocomposites are subsequently deposited onto the surface of AL microspheres through the electrostatic interaction between QC and AL. The density of Ag NPs immobilized on the surface of AL microspheres could be altered by varying the Ag content in QC–Ag nanocomposites. Optical microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, transmission electron microscopy and scanning electron microscopy were employed to follow all preparation steps and to characterize the resulting functional surfaces. The catalytic activity of the composite microspheres was evaluated by reduction of p-nitrophenol to p-aminophenol by NaBH4. The results demonstrated that the obtained microspheres exhibited excellent catalytic activity with a high reaction constant of 2.75 min−1. This was a significant enhancement compared to other Ag catalysts reported in the literature.
Co-reporter:Peng Yang, Jun You, Fangping Li, Junjie Fei, Bo Feng, Xiulan He and Jinping Zhou
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 13) pp:NaN3171-3171
Publication Date(Web):2013/05/20
DOI:10.1039/C3AY40654G
Novel gold nanoparticles (Au@QC NPs), using quaternized cellulose (QC) as the support matrix, were used to entrap hemocyanin (Hc) with the aid of carbon black. Direct electron transfer between Hc and the electrode was achieved and an electrochemical method for the simultaneous detection of hydroquinone and catechol is developed.
Co-reporter:Baoquan Jia, Yue Dong, Jinping Zhou and Lina Zhang
Journal of Materials Chemistry A 2014 - vol. 2(Issue 3) pp:NaN529-529
Publication Date(Web):2013/10/23
DOI:10.1039/C3TC31865F
In this work, regenerated cellulose (RC)–Cu nanocomposite films with interesting single-side conductive properties were prepared using in situ coating. The structure and morphology of the films were investigated with XRD, ATR-FTIR, XPS, TG, SEM, TEM and AFM analysis. The mechanical properties and conductive performance of the films were also examined. The copper of a cellulose–cuprammonium solution was employed as the coating source as opposed to the addition of other conductive substances. The single-side coating of Cu nanocomposite film was achieved by one-step reduction based on the asymmetric surface structure of RC film. A layer of Cu nanoparticles with the thickness of ∼1 μm was coated on the coagulant-contacting surface. The RC–Cu nanocomposite films displayed high single-sided conductivity (105.6 ± 63.9 S cm−1). It was found that the resistance could be tuned by changing the bending curvature. This study provides potential applications in areas such as electronic substrates, wearable electronics and sensors.
Co-reporter:Lingzhi Zhang, Chengcheng Zhao, Jinping Zhou and Tetsuo Kondo
Journal of Materials Chemistry A 2013 - vol. 1(Issue 36) pp:NaN5764-5764
Publication Date(Web):2013/06/28
DOI:10.1039/C3TC30689E
Amphiphilic cationic cellulose derivatives with different long alkyl chains as hydrophobic segments were synthesized. They can self-assemble into cationic micelles in distilled water. The structure and properties of the micelles were characterized by elemental analysis, FT-IR, 1H NMR, ζ-potential measurements, DLS, TEM, and fluorescence spectroscopy. The hydrophobic cores of the micelles were used to load a hydrophobic dye (4,7-bis[4-(1,2,2-triphenylvinyl)phenyl]benzo-2,1,3-thiadiazole, BTPETD) and exhibited a stable photoluminescence. The fluorescence emission can quantitatively and sensitively respond to 2,4-dinitrophenol (DNP) and picric acid (PA) due to the electron transfer between BTPETD and the explosives, and the limit of detection was 200 and 50 nM for DNP and PA, respectively. The novel hydrophobically modified cationic cellulose micelles have the potential to prepare feasible, sensitive and stable sensor systems for detecting explosives in aqueous solutions.
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