Co-reporter:Baoxiu Wang;Xiangguo Lv;Shiyan Chen;Zhe Li;Jingjing Yao;Xufeng Peng
Cellulose 2017 Volume 24( Issue 11) pp:5013-5024
Publication Date(Web):30 August 2017
DOI:10.1007/s10570-017-1472-x
Due to its unique properties, bacterial cellulose (BC) has attracted a great deal of interest as an implant material for tissue regeneration. However, one major problem of BC is inadequate vascularization which leads to cell apoptosis due to insufficient nutrients and oxygen supply. Herein, porous BC/gelatin (BC/Gel) scaffolds loaded with vascular endothelial growth factor (VEGF) with silk fibroin nanoparticles (VEGF-NPs) were prepared. An in vitro study indicated that VEGF was sustainably released from the BC/Gel/VEGF-NPs scaffold over 28 days. Cell viability, morphology and proliferation were evaluated using Live/Dead® viability/cytotoxicity assay, field emission scanning electron microscopy and CCK-8 assay by seeding the scaffolds with pig iliac endothelium cells. The presence of VEGF-NPs in the scaffold significantly improved cell proliferation and viability in vitro. Evaluation of in vivo biocompatibility and angiogenesis of the BC/Gel/VEGF-NPs scaffold was conducted using a dog skin defect model. Results indicated that the BC/Gel/VEGF-NPs scaffold significantly promoted vessel blood formation after implantation compared to the BC/Gel and BC/Gel/NPs scaffolds. It is concluded that angiogenesis could be improved through the incorporation of VEGF-NPs into the BC/Gel scaffold, which may enhance clinically desirable functions of BC-based scaffolds in terms of enhanced angiogenesis.
Co-reporter:Peng Ji, Jin Jin, Xianglin Chen, Chaosheng Wang and Huaping Wang
RSC Advances 2016 vol. 6(Issue 14) pp:11492-11500
Publication Date(Web):21 Jan 2016
DOI:10.1039/C5RA21018F
The water state and distribution in PET and cotton fibres were studied by low-field proton nuclear magnetic resonance. The spin–spin relaxation times (T2) were measured with single pulse free induction decay (FID). There are three different states of adsorbed water in the fibre materials. The slowest fraction T22 can be assigned to the bulk water. The intermediate component T21 can be ascribed to microporous structure confined water. The fastest fraction, T2b, can be assigned to the water molecules trapped by hydrogen bond owing to the chemical group. During desorption process of fibre materials, three types of water in the fibre materials work together to present the time-domain spectra, where three peaks are really related each other. Based on the interaction relationship between multi-structure of fibre materials and adsorbed water, PET fibre materials were chosen to investigate the adsorption and desorption behavior designed by copolymerization and morphology design method. The experiments of surface contact angle of fibre and fabric, moisture adsorption, water adsorption, wicking distance and water vapor permeability were carried out. The results show that the designed PET fibre materials have fast adsorption–desorption capacity. LF-NMR provides unique insight into the water state and distribution of multi-structure of fibre materials.
Co-reporter:Na Liu, Baochun Wang, Shiyan Chen, Fuyou Ke, Ye Chen, Qibing Pei and Huaping Wang
RSC Advances 2016 vol. 6(Issue 1) pp:1-7
Publication Date(Web):15 Dec 2015
DOI:10.1039/C5RA21583H
The solutions of cellulose diacetates (CDA) in ionic liquids, 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6) and 1-butyl-3-methylimidazolium formate ([BMIM]COOH), have been investigated to identify the solvent for optimal CDA fiber performance. The CDA/[BMIM]Cl and CDA/[BMIM]BF4 solutions both behave as typical shear-thinning fluids that are beneficial for fiber spinning. The CDA/[BMIM]Cl solution exhibits higher flowability and spinnability than the CDA/[BMIM]BF4 solution. CDA fibers with compact morphology and smooth surface have been fabricated from the [BMIM]Cl solution. The tensile strength of the resulting CDA fibers (3.00 cN per dtex) is significantly improved over that of commercial CDA fibers (1.44 cN per dtex), even when the commercial fibers (3.83 dtex) are thinner than the new CDA fibers (5.20 dtex). The present method to fabricate CDA fibers with improved mechanical properties can be directly used for the production of fabric yarns and garments.
Co-reporter:Zhe Li, Xiangguo Lv, Shiyan Chen, Baoxiu Wang, Chao Feng, Yuemin Xu and Huaping Wang
RSC Advances 2016 vol. 6(Issue 48) pp:42229-42239
Publication Date(Web):22 Apr 2016
DOI:10.1039/C6RA07685H
A significant problem limiting the application of bacterial cellulose (BC) nanofibrous scaffolds for tissue regeneration is the nanoscale pores that inhibit cell infiltration and vascularization in their three-dimensional (3D) structure. In this paper, a facile method was used to fabricate 3D microporous nanofibrous gelatin/BC composite scaffolds (Gel/BC) by stationary cultivation Gluconacetobacter xylinus using microporous gelatin scaffold as a template. The Gel/BC scaffolds with highly interconnected micropore (171 ± 71 μm) and surface decorated on the micropore walls by BC nanofibers (25.2 ± 7.0 nm) were fabricated, which are remarkably similar in structure to the native extracellular matrix (ECM). Cell distribution, viability and morphology were evaluated by seeding adipose-derived stem cells (ADSCs) on the scaffolds, using the 3D laser scanning confocal microscopy (3D-LSCM), LIVE/DEAD® viability/cytotoxicity assay and field emission scanning electron microscopy (FE-SEM). In vivo biocompatibility was evaluated by subcutaneous implantation using a dog model for 2 weeks. These results indicate that the 3D microporous nanofibrous scaffolds exhibit good biocompatibility, promoting cellular attachment, proliferation and maintain cellular phenotype, improving cellular infiltration and vascularization. It is anticipated that this 3D microporous nanofibrous scaffold can be applied in the fields such as medical implants, cell supports, and materials, which can be used as instructive 3D environments for tissue regeneration.
Co-reporter:Lian Tang;Yi Zheng;Shiyan Chen;Lei Wang
Journal of Applied Polymer Science 2016 Volume 133( Issue 11) pp:
Publication Date(Web):
DOI:10.1002/app.43120
ABSTRACT
Flexible and nonpoisonous X-ray-shielding membranes supported by bacterial cellulose (BC) were prepared, in which X-ray-shielding materials were of microcapsule structure by using polyvinyl alcohol as shell and lead salt as core. The effect of the wall/core interaction and the amount of cross-linking agent were taken into consideration to find the optimal reaction conditions. The morphology, microcapsule size, and lead salt release properties were investigated. After supported by BC, the flexible and potable membranes for X-ray radiation protection were prepared and the shielding properties were evaluated, which indicated a good X-ray-shielding material. We set up a new method to prepare flexible and portable X-ray radiation protection membranes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43120.
Co-reporter:Fangyi Guan, Shiyan Chen, Jingjing Yao, Weili Zheng, Huaping Wang
Journal of Materials Science & Technology 2016 Volume 32(Issue 2) pp:153-157
Publication Date(Web):February 2016
DOI:10.1016/j.jmst.2015.08.014
ZnS/bacterial cellulose/epoxy resin (ZnS/BC/E56) nanocomposites with good transparency and flexibility were prepared and characterized. When the precursor Zn2+ concentrations were not more than 1 wt%, the size of the introduced ZnS nanoparticles was smaller than 50 nm and the distribution was homogeneous within the composites. Under the condition, outstanding transmittance more than 70% in the visible light was obtained. By incorporation of ZnS nanoparticles with excellent thermo-optic stability to the composites, the thermo-optic coefficient was obviously increased from −361 × 10−6 to −310 × 10−6 K−1. The good flexibility, optical and mechanical properties endow the nanocomposites potential applications in the flexible optoelectronic materials.
Co-reporter:XiangGuo Lv, JingXuan Yang, Chao Feng, Zhe Li, ShiYan Chen, MinKai Xie, JianWen Huang, HongBin Li, HuaPing Wang, and YueMin Xu
ACS Biomaterials Science & Engineering 2016 Volume 2(Issue 1) pp:19
Publication Date(Web):November 16, 2015
DOI:10.1021/acsbiomaterials.5b00259
In this study, we built a bilayer nanofibrous material by utilizing the gelatinization properties of potato starch (PS) to interrupt bacterial cellulose (BC) assembly during static culture to create more free spaces within the fibrous network. Then, muscle cells were cultured on the loose surface of the BC/PS scaffolds to build biomaterials for hollow organ reconstruction. Our results showed that the BC/PS scaffolds exhibited similar mechanical characters to those in the traditional BC scaffolds. And the pore sizes and porosities of BC/PS scaffolds could be controlled by adjusting the starch content. The average nanofiber diameters of unmodified BC and BC/PS composites is approximately to that of the urethral acellular matrix. Those scaffolds permit the muscle cells infiltration into the loose layer and the BC/PS membranes with muscle cells could enhance wound healing in vivo and vitro. Our study suggested that the use of bilayer BC/PS nanofibrous scaffolds may lead to improved vessel formation. BC/PS nanofibrous scaffolds with muscle cells enhanced the repair in dog urethral defect models, resulting in patent urethra. Improved organized muscle bundles and epithelial layer were observed in animals treated with BC/PS scaffold seeded by muscle cells compared with those treated with pure BC/PS scaffold. This study suggests that this biomaterial could be suitable for tissue engineered urinary tract reconstruction and this type of composite scaffold could be used for numerous other types of hollow organ tissue engineering grafts, including vascular, bladder, ureter, esophagus, and intestine.Keywords: bacterial cellulose; hollow organ; nanofibrous scaffold; urethral reconstruction
Co-reporter:Lian Tang, Jinlu Han, Zhenlin Jiang, Shiyan Chen, Huaping Wang
Carbohydrate Polymers 2015 Volume 117() pp:230-235
Publication Date(Web):6 March 2015
DOI:10.1016/j.carbpol.2014.09.049
•Flexible conductive PPy/BC memebranes were prepared through in situ chemical synthesis.•The prepared PPy/BC nanocomposites had good amphiphobic properties.•SPPy/BC nanocomposites demonstrated a good electromagnetic shielding effectiveness.Flexible conductive polypyrrole nanocomposite membranes based on bacterial cellulose (BC) with amphiphobicity have been successfully prepared through in situ chemical synthesis and then infiltrated with polysiloxane solution. The results suggested that polypyrrole (PPy) nanoparticles deposited on the surface of BC formed a continuous core–shell structure by taking along the BC template. After modification with polysiloxane, the surface characteristics of the conductive BC membranes changed from highly hydrophilic to hydrophobic. The AFM images revealed that the roughness of samples after polysiloxane treatment increased along with the increase of pyrrole concentration. The contact angles (CAs) data revealed that the highest water contact angle and highest oil contact angle are 160.3° and 136.7°, respectively. The conductivity of the amphiphobic membranes with excellent flexibility reached 0.32 S/cm and demonstrated a good electromagnetic shielding effectiveness with an SE of 15 dB which could be applied in electromagnetic shielding materials with self-cleaning properties. It opened a new field of potential applications of BC materials.
Co-reporter:Shaobo Wang, Chaosheng Wang, Huaping Wang, Xiangling Chen, Saibo Wang
Polymer Degradation and Stability 2015 Volume 114() pp:105-114
Publication Date(Web):April 2015
DOI:10.1016/j.polymdegradstab.2015.02.006
Poly(ethylene terephthalate) (PET) was chemically recycled through glycolysis with ethylene glycol (EG) and repolycondensation of its main depolymerized product bis(2-hydroxyethyl terephthalate) (BHET). In this process, synthesized sodium titanium tris(glycolate) was used as a new catalyst for both reactions. The catalytic efficiency and selectivity of sodium titanium tris(glycolate) in both reactions has been investigated and compared with conventional catalysts used in glycolysis or polycondensation. The results indicate that sodium titanium tris(glycolate) is a desirable catalyst for chemical recycling of PET because it can present high catalytic activity and selectivity not only in glycolysis but also in repolycondensation, which means high cost of the catalysts separation between two reactions during chemical recycling process could be avoided. Meanwhile, a mechanism of the glycolysis of PET catalyzed by sodium titanium tris(glycolate) was proposed based on the results of interactions among BHET, EG and catalysts revealed by infrared spectroscopy.
Co-reporter:Zhixing Li, Na Liu, Yongbo Yao, Shiyan Chen, Haifeng Wang and Huaping Wang
RSC Advances 2015 vol. 5(Issue 2) pp:901-907
Publication Date(Web):12 Nov 2014
DOI:10.1039/C4RA10618K
1-Butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) was chosen as a plasticizer for cellulose diacetate (CDA) to investigate the feasibility of CDA melt spinning. [BMIM]BF4/CDA was characterized by Fourier transform infrared (FTIR) spectroscopy, dynamic thermomechanical analysis (TG), the degree of crystallinity (XRD), scanning electron microscopy (SEM) and the thermal stability of CDA. The rheological properties of [BMIM]BF4/CDA were investigated by a rotary rheometer and the zero-shear viscosity was predicted by the three-parameter Carreau viscosity model from apparent viscosity data. The [BMIM]BF4/CDA melt showed a shear-thinning behaviour. The melt with higher CDA concentrations and higher shear rates was found to be sensitive to temperature; thus, we could adjust the processing technology by changing the temperature and shear rate. However, the structural viscosity index of the melt decreased with increase in the [BMIM]BF4 content and went up after a decline with temperature increase.
Co-reporter:H. Saba, Y. Yongbo, W. Jianning, X. Xiaolin, W. Kaijian, Z. Yumei and W. Huaping
RSC Advances 2015 vol. 5(Issue 11) pp:8318-8322
Publication Date(Web):23 Dec 2014
DOI:10.1039/C4RA14911D
Viscoelastic properties of cellulose solutions with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) and dimethylsulfoxide (DMSO) as solvents were studied by rheological experiments. From the results of rheological behaviors, the non-monotonous decrease of viscosity with DMSO content was observed. When the content of DMSO in [BMIM]Cl/DMSO is lower than 5 wt% in [BMIM]Cl/DMSO, the viscosity and gelation temperature (Tgel) decreased with the increase of DMSO. However, the values of viscosity and Tgel showed a nonlinear change with the further increase of DMSO. It could be understood that DMSO acted as the diluent when the content of DMSO is below 5 wt%. The local micro-aggregation or micro-phase separation of cellulose could happen when the content of DMSO further increased due to the weak action between cellulose and DMSO.
Co-reporter:Yan Ge, Shiyan Chen, Jingxuan Yang, Biao Wang and Huaping Wang
RSC Advances 2015 vol. 5(Issue 69) pp:55756-55761
Publication Date(Web):19 Jun 2015
DOI:10.1039/C5RA08361C
Color-tunable luminescent membranes of CdTe QDs on bacterial cellulose (BC) nanofibers were successfully fabricated by in situ synthesis in aqueous solution. No nitrogen protection and expensive reagents are needed during the preparation process. The luminescent color of the CdTe/BC nanocomposite membranes with green, orange and red luminescence can be tuned easily by controlling the reaction time. The prepared CdTe/BC nanocomposites were characterized by X-ray diffraction (XRD), field effect scanning electron microscopy with energy dispersive X-ray analysis (FESEM-EDX) and transmission electron microscopy (TEM). Ultraviolet-visible (UV-vis), photoluminescence (PL) spectra and PL quantum efficiency (PL QE) were used to investigate the optical properties. Moreover, we attempted to make the luminescent membranes into an ion test paper. The green luminescent membranes had a good selectivity for Cu2+ with a detection limit of 0.016 mM and the mechanism of quenching Cu2+ were also explored. This work provides a simple, effective and eco-friendly method for the construction of luminescent CdTe QDs on BC membranes with high detectability for detection of Cu2+.
Co-reporter:Weili Zheng;Shiyan Chen;Siyu Zhao;Yi Zheng
Journal of Applied Polymer Science 2014 Volume 131( Issue 19) pp:
Publication Date(Web):
DOI:10.1002/app.40874
ABSTRACT
Spherical zinc sulfide (ZnS) nanoparticles dispersed on bacterial cellulose (BC) nanofibers homogeneously were successfully fabricated through in situ precipitation method using BC as template and explored the formation mechanism. The structure and properties were characterized by Fourier transform infrared, X-ray diffractometer, FESEM, and so on. The results demonstrated that the nanoparticles were sphalerite structure ZnS and the size increased with the increase of the zinc precursor concentrations. Moreover, a high photocatalytic activity (92%) for degradation of methyl orange was observed and the photoluminescence spectra of the nanocomposites exhibited a blue emission band centered at 468 nm. The flexible BC membrane carried of ZnS nanoparticles might be a promising candidate in the application fields of fluorescence and photo-catalysis. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40874.
Co-reporter:Wei-li Zheng;Wei-li Hu;Shi-yan Chen 陈仕艳;Yi Zheng
Chinese Journal of Polymer Science 2014 Volume 32( Issue 2) pp:169-176
Publication Date(Web):2014/02/01
DOI:10.1007/s10118-014-1386-0
The freshly prepared water-wet amidoximated bacterial cellulose (Am-BC) serves as an effective nanoreactor to synthesis zinc oxide nanoparticles by in situ polyol method. The obtained ZnO/Am-BC nanocomposites have been characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The influence of the zinc acetate concentration on the morphologies and size of ZnO nanoparticles and the possible formation mechanism were discussed. The results indicated that uniform ZnO nanoparticles were homogeneously anchored on the Am-BC nanofibers through strong interaction between the hydroxyl and amino groups of Am-BC and ZnO nanoparticles. The loading content of ZnO nanoparticles is higher using Am-BC as a template than using the unmodified bacterial cellulose. The resultant nanocomposite synthesized at 0.05 wt% shows a high photocatalytic activity (92%) in the degradation of methyl orange.
Co-reporter:Yi Zheng, Jingxuan Yang, Weili Zheng, Xiao Wang, Cao Xiang, Lian Tang, Wen Zhang, Shiyan Chen, Huaping Wang
Materials Science and Engineering: C 2013 Volume 33(Issue 4) pp:2407-2412
Publication Date(Web):1 May 2013
DOI:10.1016/j.msec.2013.02.007
Flexible magnetic membrane based on bacterial cellulose (BC) was successfully prepared by in-situ synthesis of the Fe3O4 nanoparticles under different conditions and its properties were characterized. The results demonstrated that the Fe3O4 nanoparticles coated with PEG were well homogeneously dispersed in the BC matrix under ultrasonic irradiation with the saturation magnetization of 40.58 emu/g. Besides that, the membranes exhibited the striking flexibility and mechanical properties. This study provided a green and facile method to inhibit magnetic nanoparticle aggregation without compromising the mechanical properties of the nanocomposites. Magnetically responsive BC membrane would have potential applications in electronic actuators, information storage, electromagnetic shielding coating and anti-counterfeit.Highlights► Flexible magnetic film is prepared by in situ synthesis on bacterial cellulose. ► Ultrasound and PEG are used together to inhibit the nanoparticle aggregation. ► The magnetic membrane demonstrates the great superparamagnetic behavior.
Co-reporter:Zhenhua Yang, Shiyan Chen, Weili Hu, Na Yin, Wen Zhang, Cao Xiang, Huaping Wang
Carbohydrate Polymers 2012 Volume 88(Issue 1) pp:173-178
Publication Date(Web):17 March 2012
DOI:10.1016/j.carbpol.2011.11.080
Flexible luminescent membranes based on bacterial cellulose (BC) were successfully fabricated by the in situ synthesis of the CdSe nanoparticles on the BC nanofibers. X-ray diffraction (XRD) patterns and field emission scanning electron microscopy (FE-SEM) revealed that CdSe nanoparticles were homogeneously dispersed on the BC nanofibers. The thermal stability of BC was greatly increased with the inclusion of CdSe nanoparticles. The CdSe/BC nanocomposite exhibited good photoluminescence properties and excellent mechanical properties. This work provides an effective method for the construction of flexible BC membranes with photoluminescence properties, which are promising for applications in the fields of security papers, sensors and flexible luminescent membranes.Highlights► Flexible luminescent nanocomposite membrane is prepared by in situ method. ► Thermal stability of bacterial cellulose is improved by embedding CdSe nanoparticles. ► The nanocomposite shows good mechanical properties and photoluminescence properties.
Co-reporter:Guansen Jiang, Weifeng Huang, Lin Li, Xiao Wang, Fengjian Pang, Yumei Zhang, Huaping Wang
Carbohydrate Polymers 2012 Volume 87(Issue 3) pp:2012-2018
Publication Date(Web):14 February 2012
DOI:10.1016/j.carbpol.2011.10.022
The crystalline and microstructure of the regenerated cellulose fibers prepared from different solvents and technology processes were investigated by synchrotron wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS). WAXD results indicated that the crystal orientation, crystallinity of Lyocell and IL-cell fibers were higher than those of Viscose and Newdal fibers. The size of micro-voids located in the cross-section of regenerated cellulose fibers was analyzed based on the results of SAXS. And the technology process had little effect on the radius of the micro-voids. The micro-voids in Viscose and Newdal fibers have longer length (L) and greater misorientation (BΦ) than that in Lyocell and IL-cell fibers. This reveals that the average void volumes of Viscose and Newdal fibers were larger. Furthermore, the regenerated cellulose fibers from dry-jet-wet-spinning process exhibited completely a higher E-modulus, tenacity than the fibers spun by wet-spinning method did.Highlights► We comparatively discussed four kinds of regenerated cellulose fibers which from the traditional and modified Viscose process, NMMO and ionic liquids process, respectively. ► The crystal orientation, crystallinity, micro-morphology as well as mechanical properties of both Lyocell and ILs–cell fibers were better than that of Viscose and Newdal fibers.
Co-reporter:Na Yin, Shiyan Chen, Zhe Li, Yang Ouyang, Weili Hu, Lian Tang, Wen Zhang, Bihui Zhou, Jingxuan Yang, Qiushu Xu, Huaping Wang
Materials Letters 2012 Volume 81() pp:131-134
Publication Date(Web):15 August 2012
DOI:10.1016/j.matlet.2012.04.133
Bacterial cellulose (BC) with a porous structure was prepared via a facile surfactant-assisted foaming method in azodicarbonamide (AC)-NaOH aqueous solution under mild condition. The time-saving and flexible procedure comprises immersing and foaming of BC membranes in AC solution, washing and subsequent freeze drying. The results showed that BC with the surfactant Tween 80 assisted foaming treatment had the homogeneous and interconnected spherical macroporous structure with the pore size up to 20 μm. Compared to native BC, its mesoporous surface area was increased from 56.87 m2/g to 169.86 m2/g, the porosity was increased from 28.3% to 90.8% and the maximum water adsorption was increased from 997% to 7611%.Highlights► BC with porous structure was prepared by surfactant-assisted foaming. ► Porous structure consisted of uniformly spherical macropores and enlarged mesopores. ► The maximum water adsorption of hierarchically porous BC reached up to 7611%. ► The promising porous BC can be used in adsorption, separation and other applications.
Co-reporter:Weili Hu, Shiyan Chen, Qiushu Xu, Huaping Wang
Carbohydrate Polymers 2011 Volume 83(Issue 4) pp:1575-1581
Publication Date(Web):1 February 2011
DOI:10.1016/j.carbpol.2010.10.016
Bacterial cellulose preserving the microfibrillar morphology was partially acetylated by the solvent-free acetylation method using acetic anhydride in the presence of iodine as a catalyst. The results showed that within the range of catalyst amounts studied, the overall degree of substitution increased as the amount of iodine used increased. We also found that the reaction time and temperature had an active influence on the extent of acetylation. X-ray diffraction profiles indicated that acetylation proceeded from the surface to the interior of BC nanofibers, and scanning electron microscopy images revealed that even low levels of acetylation were effective to make the nanofibers separated from each other. NMR analysis indicated the regio-nonselective reactivity of the OH groups in the glucose units in the acetylation process. The obtained acetylated BC membrane shows more hydrophobic surface and good mechanical properties which is in favor of enhancing the hydrophobic non-polar polymeric matrix.
Co-reporter:Ye Chen, Yumei Zhang, Fuyou Ke, Jihan Zhou, Huaping Wang, Dehai Liang
Polymer 2011 Volume 52(Issue 2) pp:481-488
Publication Date(Web):21 January 2011
DOI:10.1016/j.polymer.2010.11.034
The solubility and chain conformation of different types of homopolymers in low viscosity ionic liquids (ILs), 1-allyl-3-methylimidazolium chloride ([AMIM][Cl]) at 50 °C and 1-butyl-3-methylimidazolium formate ([BMIM][COOH]) at 25 °C, were studied by laser light scattering (LLS). For neutral polymers, such as polyvinyl alcohol and polysulfonamide, aggregation occurred in all the cases except for polyvinyl alcohol in [BMIM][COOH]. For negative polyelectrolytes, such as DNA and polystyrene sulfonate, single chain conformation was observed. However, the hydrodynamic radius of both polymers was much smaller than that in good solvents, suggesting that the chains were condensed. Cellulose was soluble in [AMIM][Cl], and non-diffusive mode was observed by dynamic light scattering. Zeta potential analysis indicated that cellulose exhibited the feature of polyelectrolyte. The solubility of homopolymers could be qualitatively explained by treating polymer/IL as a ternary system: polymer, cation, and anion. It was the mutual interactions determined the solubility and conformation of polymers in ILs.
Co-reporter:Wen Zhang, Shiyan Chen, Weili Hu, Bihui Zhou, Zhenhua Yang, Na Yin, Huaping Wang
Carbohydrate Polymers 2011 86(4) pp: 1760-1767
Publication Date(Web):
DOI:10.1016/j.carbpol.2011.07.015
Co-reporter:Na YIN, Shi-yan CHEN, Yang OUYANG, Lian TANG, Jing-xuan YANG, Hua-ping WANG
Progress in Natural Science: Materials International 2011 Volume 21(Issue 6) pp:472-477
Publication Date(Web):December 2011
DOI:10.1016/S1002-0071(12)60085-9
AbstractHydroxyapatite (HAp)/bacterial cellulose (BC) nanocomposites were prepared by an optimal biomimetic mineralization synthesis approach for bone tissue engineering application. BC with ultrafine three dimensional network was negatively charged by the adsorption of polyvinylpyrrolidone (PVP) to initiate the nucleation of HAp. The HAp was grown in vitro along the nanofiber network of BC via dynamic simulated body fluid (SBF) treatment. It was found that rod-like HAp particles in the nano-scale (100–200 nm) homogeneously deposited on the surface of PVP-BC. ATR-Fourier Transform Infrared Spectroscopy (ATR-FTIR) results showed that carbonate-containing HAp crystals resembling natural bones were formed by biomimetic mineralization method. Moreover, the amount of HAp observed increased with increasing mineralization time. And the Ca/P overall ratio ranged from 1.37 to 1.59. The results from Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) indicated that PVP treatment enhanced the apatite nucleation ability of BC with higher HAp deposit amount.
Co-reporter:Weili Hu;Shuiping Liu;Shiyan Chen
Cellulose 2011 Volume 18( Issue 3) pp:655-661
Publication Date(Web):2011 June
DOI:10.1007/s10570-011-9520-4
The photochromic bacterial cellulose (BC) nanofibrous membranes containing 1′,3′,3′-trimethyl-6-nitrospiro(2H-1-benzopyran-2,2′-indoline) (NO2SP) were successfully prepared by surface modification of BC nanofibers with spiropyran photochromes, and their physical and photochromic properties were characterized. The FTIR spectra indicated the interaction between BC and NO2SP which leads to the uniform dispersion of NO2SP in the nanofibrous membrane. SEM results demonstrated that the introduction of NO2SP maintains the nanofibrous network structure of BC. UV/vis spectrometry of the resulting BC-NO2SP revealed that the membranes show reversible photochromic property by changing their color from colorless to pink forming a merocyanine structure upon UV irradiation, and returning back again to colorless spiropyran structure by visible light. The contact angle of the BC-NO2SP with water was found to be reversibly regulated due to the reversible isomerization of the spiropyran moieties in BC-NO2SP. The result indicates that the surface modification with spiropyran photochromes expands new applications of BC nanofibers and such photochromic nanofibers with excellent photosensitivity have great potentials for sensitive displays, biosensors and other optical devices.
Co-reporter:Weili Hu, Shiyan Chen, Luting Liu, Bin Ding, Huaping Wang
Sensors and Actuators B: Chemical 2011 Volume 157(Issue 2) pp:554-559
Publication Date(Web):20 October 2011
DOI:10.1016/j.snb.2011.05.021
A novel formaldehyde sensor based on nanofibrous polyethyleneimine (PEI)/bacterial cellulose (BC) membranes coated quartz crystal microbalance (QCM) has been successfully fabricated. The nanoporous three-dimensional PEI/BC membranes are composed of nanofibers with diameter of 30–60 nm. The sensor showed high sensitivity with good linearity and exhibited a good reversibility and repeatability towards formaldehyde in the concentration range of 1–100 ppm at room temperature. Moreover, the results showed that the sensing properties were mainly affected by the content of PEI component in nanofibrous membranes, concentration of formaldehyde and relative humidity. Additionally, the nanofibrous PEI/BC membrane coated QCM sensors exhibited a good selectivity to formaldehyde when tested with competing vapors. The simple and feasible method to prepare and coat the PEI/BC sensing membranes on QCM makes it promising for mass production at a low cost.
Co-reporter:Weili Hu, Shiyan Chen, Bihui Zhou, Luting Liu, Bin Ding, Huaping Wang
Sensors and Actuators B: Chemical 2011 Volume 159(Issue 1) pp:301-306
Publication Date(Web):28 November 2011
DOI:10.1016/j.snb.2011.07.014
A novel highly stable and sensitive humidity sensor based on bacterial cellulose (BC) coated quartz crystal microbalance (QCM) has been successfully fabricated. The results showed that the sensors possessed good sensing characteristics by increasing more than two orders of magnitude with increasing relative humidity (RH) from 5 to 97%, and the Log(Δf) showed good linearity (20–97% RH). The sensitivity of sensors coated with BC membranes was four times higher than that of the corresponding cellulose membranes at 97% RH. In addition, the sensor sensitivity is greatly enhanced by increasing the coating load of the BC membranes with more absorption sites in the sensing membranes. Moreover, the experimental results prove that the resultant sensors exhibited a good reversible behavior and good long term stability. Herein, not only a novel and low-cost humidity sensor material was exploited, but also a new application area for BC nanofibrous membranes was opened up.
Co-reporter:Weili Hu, Shiyan Chen, Zhenhua Yang, Luting Liu, and Huaping Wang
The Journal of Physical Chemistry B 2011 Volume 115(Issue 26) pp:8453-8457
Publication Date(Web):June 14, 2011
DOI:10.1021/jp204422v
The novel conductive polyaniline/bacterial cellulose (PANI/BC) nanocomposite membranes have been synthesized in situ by oxidative polymerization of aniline with ammonium persulfate as an oxidant and BC as a template. The resulting PANI-coated BC nanofibrils formed a uniform and flexible membrane. It was found that the PANI nanoparticles deposited on the surface of BC connected to form a continuous nanosheath by taking along the BC template, which greatly increases the thermal stability of BC. The content of PANI and the electrical conductivity of composites increased with increasing reaction time from 30 to 90 min, while the conductivity decreased because of the aggregation of PANI particles by further prolonging the reaction time. In addition, the acids remarkably improve the accessibility and reactivity of the hydroxyl groups of BC. The results indicate that the composites exhibit excellent electrical conductivity (the highest value was 5.0 × 10–2 S/cm) and good mechanical properties (Young’s modulus was 5.6 GPa and tensile strength was 95.7 MPa). Moreover, the electrical conductivity of the membrane is sensitive to the strain. This work provides a straightforward method to prepare flexible films with high conductivity and good mechanical properties, which could be applied in sensors, flexible electrodes, and flexible displays. It also opens a new field of potential applications of BC materials.
Co-reporter:Weili Hu, Shiyan Chen, Bihui Zhou, Huaping Wang
Materials Science and Engineering: B 2010 170(1–3) pp: 88-92
Publication Date(Web):15 June 2010
DOI:10.1016/j.mseb.2010.02.034
ZnO nanoparticles with a pure wurtzite structure have been successfully synthesized through decomposing bacterial cellulose infiltrated with zinc acetate aqueous solution at high temperature. The effects of the concentration of zinc acetate aqueous solution, the calcination temperature, and the templates on the average particle size and morphology of the ZnO nanoparticles were investigated. The prepared ZnO nanoparticles were characterized by FESEM, XRD, FTIR and TG–DTA. The results suggest that bacterial cellulose plays an important role in preventing the ZnO nanoparticles from aggregating under optimized conditions. The calcination temperature has great effects on the morphologies of ZnO nanoparticles. When calcinating at 600 °C and using BC as the template with 1 wt.% zinc acetate aqueous solution, well-dispersed and regular ZnO nanoparticles with a narrow size distribution of 20–50 nm and high photocatalytic activity were obtained.
Co-reporter:Xin Li, Shiyan Chen, Weili Hu, Shuaike Shi, Wei Shen, Xiang Zhang, Huaping Wang
Carbohydrate Polymers 2009 Volume 76(Issue 4) pp:509-512
Publication Date(Web):16 May 2009
DOI:10.1016/j.carbpol.2008.11.014
CdS nanoparticles have been synthesized and stabilized on unique bacterial cellulose (BC) nanofibers in situ. The obtained nanocomposite material have been characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transformed infrared (FTIR), thermogravimetric analysis (TGA), ultraviolet–visible (UV–Vis) and photoluminescence (PL) spectroscopy. The results indicated that CdS nanoparticles of about 30 nm diameter deposited on BC nanofibres are well-dispersed in the BC nanofibre-network and the uniform spherical CdS nanoparticles are comprised of nano-sized CdS crystal. Moreover, the crystallite sizes of CdS crystals are about 8 nm. The nanocomposites would have potential application as photocatalyst, novel luminescence and photoelectron transfer devices.
Co-reporter:Wei Shen, Shiyan Chen, Shuaike Shi, Xin Li, Xiang Zhang, Weili Hu, Huaping Wang
Carbohydrate Polymers 2009 Volume 75(Issue 1) pp:110-114
Publication Date(Web):5 January 2009
DOI:10.1016/j.carbpol.2008.07.006
Diethylenetriamine-bacterial cellulose (EABC) was synthesized by amination with diethylenetriamine on bacterial cellulose (BC). Its adsorption properties for Cu(II) and Pb(II) were investigated. The parameters affecting the metal ions adsorption, such as contact time, solution pH, and initial metal ions concentration have been investigated. The adsorption kinetics and adsorption isotherms were further studied. The results show that the adsorption rate could be well fitted by pseudo-second-order rate model, and adsorption isotherm could be described by the Langmuir model. The regeneration of EABC was also studied. This study provides the relatively comprehensive data for the EABC application to the removal of metal ion in the wastewater.
Co-reporter:Shuaike Shi;Shiyan Chen;Xiang Zhang;Wei Shen;Xin Li;Weili Hu
Journal of Chemical Technology and Biotechnology 2009 Volume 84( Issue 2) pp:285-290
Publication Date(Web):
DOI:10.1002/jctb.2037
Abstract
BACKGROUND: Both hydroxyapatites (HAp) and bacterial cellulose (BC) are excellent biomaterials. The former has outstanding osteoconductivity and bioactivity, while the latter has been proven to be a remarkably versatile biomaterial. By alkaline treatment, Ca2+ activation, and biomimetic mineralization, the nanocomposites (CaDHCAp/BC) consisting of calcium-deficient carbonate-containing hydroxyapatite (CaDHCAp) in the three-dimensional (3D) network of BC nanofibers were synthesized.
RESULTS: The CaDHCAp/BC nanocomposites obtained were characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD). The results indicated that alkaline treatment improved the apatite nucleation ability of BC, and the apatite crystals deposited along BC nanofibers were partially substituted with calcium carbonate and the uniform spherical apatite particles were composed of squama-shaped nano-sized apatite crystals. The crystallite sizes of apatite crystals are below 10 nm and the crystallinities are below 1%. The formation mechanism of CaDHCAp crystals along the BC fibers was described.
CONCLUSION: Alkaline treatment was introduced before the biomimetic mineralization process. Compared with the results without alkaline treatment, the mineralization efficiency was obviously improved. The nanocomposites obtained may have potential application as an orthopedic biomaterial. Copyright © 2008 Society of Chemical Industry
Co-reporter:Shiyan Chen;Wei Shen;Feng Yu
Polymer Bulletin 2009 Volume 63( Issue 2) pp:283-297
Publication Date(Web):2009 August
DOI:10.1007/s00289-009-0088-1
Removal of Cu2+ and Pb2+ from aqueous solutions by adsorption onto amidoximated bacterial cellulose (Am-BC) was investigated. The effects of pH, initial concentration, contact time and temperature were studied in batch experiments. The pseudo-first and pseudo-second orders and intraparticle diffusion equation were used to evaluate the kinetic data and the constants were determined. The experimental data fits well to the pseudo-second order kinetic model, which indicates that the chemical adsorption is the rate-determining step, instead of mass transfer. The equilibrium adsorption data were described by the Langmuir, Freundlich, and Temkin isotherms. The Am-BC showed a better fit to the Langmuir isotherm. The separation factor (RL) revealed the favorable nature of the isotherm. The thermodynamic parameters (ΔHads0, ΔSads0, ΔGads0) for Cu2+ and Pb2+ adsorption onto Am-BC were also determined from the temperature dependence. The values of enthalpy and entropy indicated that this process was spontaneous and exothermic. The experimental studies indicate that Am-BC would be a potential effective adsorbent to remove the metal ions from wastewater.
Co-reporter:Bo Wu, Yu M. Zhang and Hua P. Wang
Journal of Chemical & Engineering Data 2009 Volume 54(Issue 5) pp:1430-1434
Publication Date(Web):October 28, 2008
DOI:10.1021/je800622e
Densities, limiting molar conductivities (Λ0), and Walden products (Λ0η) for 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4])−sucrose−water solutions were determined at 298.15 K. The measured densities were used to calculate the apparent molar volumes of sucrose (VΦ,S) and [Bmim][BF4] (VΦ,IL) in the studied solutions. Infinite dilution apparent molar volumes, VΦ,S∞ and VΦ,IL∞, have been evaluated, together with the standard transfer volumes of the sucrose (ΔtVS∞) from water to aqueous solutions of [Bmim][BF4] and those of [Bmim][BF4] (ΔtVIL∞) from water to aqueous sucrose solution. It was shown that the ΔtVS∞ and ΔtVIL∞ values are positive and increase with increasing molalities of [Bmim][BF4] and sucrose, respectively. The volumetric interaction parameters for [Bmim][BF4]−sucrose pairs in water were also obtained and interpreted by the structural interactions model. Additionally, the Λ0 values for [Bmim][BF4] decrease with the molality of sucrose (mS), as well as Walden products (Λ0η), due to the preferential solvation of ions by sucrose molecules.
Co-reporter:Weili Hu, Shiyan Chen, Xin Li, Shuaike Shi, Wei Shen, Xiang Zhang, Huaping Wang
Materials Science and Engineering: C 2009 29(4) pp: 1216-1219
Publication Date(Web):
DOI:10.1016/j.msec.2008.09.017
Co-reporter:Bo Wu, Yumei Zhang and Huaping Wang
The Journal of Physical Chemistry B 2009 Volume 113(Issue 36) pp:12332-12336
Publication Date(Web):August 17, 2009
DOI:10.1021/jp905252j
In this contribution, we examined the effect of ethanol on the structural organization of aqueous solution of ionic liquids (ILs) using the near-infrared (NIR) technique and two-dimensional (2D) correlation spectra. The ILs used here are 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) and 1-allyl-3-methylimidazolium chloride ([Amim]Cl). It was easily found, from the distinct change tendency of NIR spectra for their aqueous solution, that the added ethanol exerted a different effect on the solution structure of [Bmim]BF4 and [Amim]Cl. For [Amim]Cl/H2O, it was deduced that ethanol molecules prefer to compete with water by interacting with imidazolium C2−H rather than C4,5−H groups, accompanied by the formation of C2−H···O interactions with ethanol molecules, while ethanol molecules do not interact specifically with any imidazolium C−H groups for [Bmim]BF4. Furthermore, it was shown that the nonpolar tail of [Amim]Cl is more sensitive to the decrease of polarity or dielectric constant of solvents than its polar head, whereas the converse is true for [Bmim]BF4. However, for both ILs, ethanol molecules were capable of changing the interaction between cations and water, anions and water by introduction of C−H···O interactions with cations, as well as the strong hydrogen-bond interactions between the anions and the hydroxyls of the ethanol. This information is suggestive for recycling the hydrophilic ILs by distillation from their aqueous diluted solutions, as well as for purifying hygroscopic ILs.
Co-reporter:Bo Wu Dr.;Yang Liu Dr.;Yumei Zhang
Chemistry - A European Journal 2009 Volume 15( Issue 28) pp:6889-6893
Publication Date(Web):
DOI:10.1002/chem.200802742
Abstract
In this contribution, an insight into the interactions between ionic liquids (ILs), 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim]BF4, and 1-allyl-3-methylimidazolium chloride, [Amim]Cl, and water is presented using near-infrared (NIR) spectroscopic measurements. Distinct differences were found in the NIR spectra of pure [Amim]Cl and [Bmim]BF4, whereby we propose optimized conformations. It was found that the relative position of the anion with respect to imidazolium cation is different in these two ILs. The geometry difference determined their different interaction modes with water, for example, the NIR spectra in alkyl group region were different for these two ILs/H2O mixtures, irrespective of being in a water-rich region or IL-rich region. However, their NIR spectra for aromatic group were similar, whereby we deduced that for both ILs, the water molecules were favorable to form hydrogen bonds with the proton H2 on imidazolium ring, rather than H4 and H5. Furthermore, it was shown that water molecules preferred to interact with BF4−, but Cl− interacted more specifically with aromatic C-H groups compared with BF4−. This was confirmed by the fact that the supramolecular structure of aqueous [Bmim]BF4 solution was destroyed as mole fraction of water surpasses 0.3979, which was lower than the value of 0.5822 for [Amim]Cl/H2O. These results would have important directive significance for the study of the aggregation behavior and recovery of hydrophilic ILs in water.
Co-reporter:Bo Wu;WeiWei Liu;YuMei Zhang Dr.
Chemistry - A European Journal 2009 Volume 15( Issue 8) pp:1804-1810
Publication Date(Web):
DOI:10.1002/chem.200801509
Co-reporter:Hongyan Zhang;Yumei Zhang;Weiwei Liu
Journal of Applied Polymer Science 2008 Volume 110( Issue 1) pp:244-252
Publication Date(Web):
DOI:10.1002/app.28643
Abstract
The kinetics of methyl methacrylate (MMA) homopolymerization performed by atom transfer radical polymerization (ATRP) is investigated in detail using ethyl-2-bromopropionate (EPN-Br) as initiator, CuBr as catalyst, and pentamethyldiethylenetriamine (PMDETA) as ligand in ionic liquids (ILs) and acetonitrile. ILs in this research covered two different substitutional imidazolium cations and anions including halogen and halogen-free ones. The typical cations include 1-butyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium and the typical anions include bromide, tetrafluoroborate. The effects of solvents, temperature, and reaction ingredients ratios on the polymerization kinetics are all investigated in this article and the apparent energy of activation (ΔE) calculated for the ATRP of MMA in 1-butyl-3-methyl-imidazolium tetrafluoroborate is 6.95 KJ/mol. The number-average molecular weights (Mn) increase linearly with conversion but are much higher than the theoretical values. It is probably due to the low concentration of deactivator at the early stage of polymerization and the lower bond energy of C-Br in PMMA-Br than that in EPN-Br. Moreover, the catalyst is easily separated from the polymer and the regenerated catalyst is reused for more than three times. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Co-reporter:Bo Wu, Yumei Zhang, Huaping Wang and Lingling Yang
The Journal of Physical Chemistry B 2008 Volume 112(Issue 41) pp:13163-13165
Publication Date(Web):September 20, 2008
DOI:10.1021/jp805483k
In this work, temperature dependence of phase behaviors for the [Bmim]BF4 + sucrose + water system was investigated. It was found that interaction of [Bmim]BF4 with sucrose is exothermic, and lowering temperature is favorable for phase separation. In addition, a “[Bmim]+-induced structural changes” model was developed and used to interpret the temperature effect, whereby the salting-out effect was thought to be an entropy driving process through analysis of the structural interaction and the electrostatic interaction.
Co-reporter:Yan Zhang;Chuanxiong Zhang;Yuehua Chen
Journal of Materials Science 2007 Volume 42( Issue 19) pp:8035-8039
Publication Date(Web):2007 October
DOI:10.1007/s10853-006-1308-9
Moisture transporting in fiber assembly is one of the critical factors affecting physiological comfort. In this study, we investigated at the capillary flow in complex geometries representative of the void spaces formed between fibers in shaped polymer fiber bundles. Dynamic process of liquid creeping in capillary is analyzed based on Reed and Wilson vertical wicking model. Critical equivalent radius values of capillary tubes in polymer fiber assembly are discussed here. In the cases of round, criss-cross and triangle shape fiber, Reed and Wilson model is integrated with shaped fiber bundle mathematical simulation model (MFB) to calculate the dynamic curve of liquid arising. Instantaneous wicking velocity, wicking height, wicking flux, and characters are compared to figure out that the wicking effect of shaped polymer fiber is quite better than normal round one.
Co-reporter:Y. Zhang;H. P. Wang;Y. H. Chen
Journal of Applied Polymer Science 2006 Volume 102(Issue 2) pp:1405-1412
Publication Date(Web):28 JUL 2006
DOI:10.1002/app.24261
Moisture transport in fiber assembly is one of the critical factors affecting physiological comfort. It is useful to model bundle structure for understanding capillary flow in complex geometries representative of the void spaces formed between fibers. A new mathematical model MFB has been used to simulate alignment representative of void spaces formed between fibers in noncircular cross section fiber bundles. Fiber morphological character and their random packing pattern are emphasized to discuss the mechanism of capillary flow in fiber assembly in this work. Capillary equivalent radius distribution, flux of saturated fiber bundle, capillary generating ability, and wicking velocity are computed to predict which kind of shape is predominant for hydrophobic polyester fiber wicking. Vertical wicking model of polyester filaments bundle predicts that as the nonroundness of filaments increase, the maximum liquid height, flux of saturated bundle, and capillary forming ability will increase, while instantaneous wicking velocity increases not stably. Concave polygon shape of fiber bundle has much more small capillary tubes than convex shape of fiber bundle. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1405–1412 2006
Co-reporter:Liang Cheng;Tingting Zhao;Yumei Zhang
Macromolecular Symposia 2004 Volume 216(Issue 1) pp:9-16
Publication Date(Web):5 OCT 2004
DOI:10.1002/masy.200451202
Free radical polymerization of acrylonitrile (AN) in ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), 2,2;m1-azobisisobutyronitrile (AIBN) as initiator was investigated. Early investigations on polymerizations using ionic liquids indicate that they serve as especially good solvents to achieve high molecular weight polymers. Free radical polymerizations result in higher molecular weight polymers, for ionic liquids have low chain transfer constants and act to stabilize the active radical during the process of polymerization. The thermal stability of polymers synthesized in ionic liquids have be improved obviously than that in traditional solvents.
Co-reporter:Yan Chen, Shiyan Chen, Baoxiu Wang, Jingjing Yao, Huaping Wang
Carbohydrate Polymers (15 March 2017) Volume 160() pp:
Publication Date(Web):15 March 2017
DOI:10.1016/j.carbpol.2016.12.020
•A novel nanohybrid was successfully fabricated by deposition of AuNPs onto TOBCNs.•The size and amount of AuNPs can be affected by TOBCNs concentration and pH value.•AuNPs/TOBCNs nanohybrids exhibited superior catalytic properties.A novel nanohybrid was successfully fabricated by deposition of gold nanoparticles (AuNPs) onto the surface of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized bacterial cellulose nanofibers (TOBCNs). The prepared AuNPs/TOBCNs nanohybrids were characterized by UV–vis spectral analysis, XRD, TEM and HRTEM. Their catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) was estimated by UV–vis spectrometry. The results showed that the AuNPs/TOBCNs nanohybrids possessed AuNPs with an average diameter of 4.30 ± 0.97 nm exhibited superior catalytic properties for the reduction of 4-NP to 4-AP. The influences of the content of reducing agent and system temperature on the catalytic property were studied. Moreover, the turnover frequency of AuNPs/TOBCNs was 750 h−1, which is higher than most recently reported AuNPs-based catalysts. This work reported a heterogeneous catalyst based on TOBCNs supported AuNPs with superior catalytic properties.
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