JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Feiya Fu,Jiayuan Gu,Ruihong Zhang,Xinyi Xu,Xiaodong Yu,Lin Liu,Xiangdong Liu,Jinping Zhou,Juming Yao
Cellulose based Ag-functionalized ZnO nanocomposite (AZC) films were prepared using a green and easy scale-up strategy. Firstly, ZnO embedded cellulose (ZC) nanocomposite was synthesized from a cellulose-NaOH/zincate/urea solution through a biomimetic approach. Secondly, Ag nanoparticles (NPs) with a mean diameter of 53.2 nm were efficiently deposited onto the surface of embedded ZnO in cellulose matrix under UV irradiation (16 w), yielding the multi-hybrid AZC film. Owing to the porous structure of cellulose substrate and its rich hydroxyl group , the NPs in the ACZ films displayed good stability. Because of the formation of Schottky barriers in the Ag-ZnO regions, the catalytic activity of ACZ films increased by 20 times when compared to that of ZC sample. Furthermore, the AZC films could completely inhibit both S. aureus and E. coli growth. This facile and eco-friendly approach is expected to pave the way for constructing multifunctional cellulose material for various niche applications.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2018
·
IF 3.789
Peiqian Zhang,Mimi Chen,Yuhao Duan,Renliang Huang,Rongxin Su,Wei Qi,Wim Thielemans,Zhimin He
Effective regulation of cellulase adsorption is key to improving the efficiencies of the two major bottlenecks of lignocellulose hydrolysis and cellulase recovery. In this work, we investigated the effect of inhibitors, pH, and temperature on the adsorption of exo- and endoglucanases (Cel7A and Cel7B, respectively) on cellulose using quartz crystal microgravimetry with dissipation. The addition of glucose and cellobiose can both inhibit the hydrolysis activity of Cel7A, whereas only cellobiose can inhibit that of Cel7B. Notably, the adsorption was favored by acidic conditions (pH ≤ 4.8) and low temperature, whereas alkaline conditions (pH 9 and 10) facilitated enzyme desorption, which is useful to guide the process of cellulase recovery. The adsorption and hydrolysis activity of Cel7A and Cel7B were both higher at 45 °C than at 25 °C. These findings pave the way to effective regulation of cellulase adsorption and thus improve lignocellulose conversion and cellulase recovery.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2018
·
IF 6.434
Chirag B. Godiya,Xiao Cheng,Dawei Li,Zhan Chen,Xiaolin Lu
A new bio-based bilateral hydrogel containing carboxymethyl cellulose (CMC) and polyacrylamide (PAM) was prepared for the wastewater remediation. The obtained CMC/PAM composite hydrogel reveals a strong single-ion affinity for copper (Cu II ), lead (Pb II ) and cadmium (Cd II ) ions, as well as multi-ion absorbability with its equilibrium data following the Langmuir adsorption model and its adsorption process abiding by a pseudo-second-order kinetics. To demonstrate its recycled use for the metal ions, the adsorbed Cu II ions in the hydrogel were reduced in situ to form homogeneously dispersed Cu nanoparticles (NPs), leading to the Cu NPs-loaded CMC/PAM hydrogel. Reduction of 4-nitrophenol to 4-aminophenol with high efficiency was successfully achieved by this Cu NPs-loaded CMC/PAM hydrogel, verifying the hydrogel’s dual functionalities towards the wastewater treatment and catalytic application.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2018
·
IF 5.807
Jianbin Ye,Shanshan Zheng,Zhan Zhang,Feng Yang,Ke Ma,Yinjie Feng,Jianqiang Zheng,Duobin Mao,Xuepeng Yang
In this study, bacterial cellulose (BC) was synthesized by Acetobacter xylinum ATCC 23767 using tobacco waste extract (TWE) as a carbon source. Nicotine was found to be an inhibitory factor for BC synthesis, but it can be removed at pH 9.0 by steam distillation. After removing nicotine, the BC production was 2.27 g/L in TWE prepared with solid-liquid (S-L) ratio at 1:10. To further enhance the BC production, two fermentation stages were performed over 16 days by re-adjusting the pH to 6.5 at 7 days, after the first fermentation stage was completed. Using this two-stage fermentation, the BC production could reach 5.2 g/L. Structural and thermal analysis by FE-SEM, FT-IR, XRD and TGA showed the properties of BC obtained from TWE were similar to that from Hestrin-Schramm (HS) medium. Considering the huge disposal tobacco waste in China, the present study provides an alternative methodology to synthesize BC.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Qing Zhu,Yuxia Jin,Wen Wang,Gang Sun,Dong Wang
Biomimetic actuators with rapid response speed, high sensitivity, and selectivity to external stimulus have found potential applications in smart switches, artificial muscles, and soft robots. The nanoscale structures of actuators enhance the exposed area to stimulus as well as enable versatile control of the actuation behaviors. Freestanding, flexible, and porous water-driven actuators with poly(vinyl alcohol-co-ethylene) (EVOH) nanofibers as the substrate and super hydrophilic nanoscale cellulose materials (cellulose nanofibers, cellulose nanocrystals, bacterial cellulose) as the active substance via uniform mixing or surface depositing were fabricated. The effects of the EVOH nanofiber substrate, the structures and concentrations of nanoscale cellulose materials, as well as the different environmental stimuli like humidity and temperature on the performance of actuators were studied. The water-driven actuation mechanism was proposed from the macroscopic and molecular aspects and the analysis of Gibbs free energy and mechanical energy. The actuator could bend to an angle of 180° and recovered less than 1 s for more than 100 circles without compromising properties when the environmental moisture changed. Furthermore, the multidimensional deformation behaviors of the water-stimulated actuators could also be well tuned by varying the orientations of the nanoscale materials. Additionally, the applications of the prepared actuator were demonstrated.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 48
·27045-27053
·
IF 2.936
Dan Cheng,Pingdong Wei,Lina Zhang,Jie Cai
Here, we present the preparation of hydrophobic nanoporous cellulose gel-g-poly(glycidyl methacrylate) (NCG-g-PGMA) nanocomposites by surface-initiated atom transfer radical polymerization (SI-ATRP) of glycidyl methacrylate (GMA) monomers and hydrophobic modification with pentadecafluorooctanoyl chloride (C7F15COCl) on the cellulose nanofibrils of the NCG. The successful grafting of PGMA and hydrophobic modification of C7F15CO– groups on the NCG was evaluated by Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed that the SI-ATRP and hydrophobic modification did not change the microscopic morphology and structure of the NCG-g-PGMA nanocomposites. Dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) showed remarkable thermomechanical properties and moderate thermal stability. The method has tremendous promise to use NCG as a platform for SI-ATRP and produce new functional NCG-based nanomaterials.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Qilin Lu,Songhua Zhang,Mingcheng Xiong,Fengcai Lin,Lirong Tang,Biao Huang,Yandan Chen
Inspired by the supramolecular structure of cellulose, cellulose-gelatin supramolecular hydrogels with high strength and pH-sensitivity were constructed in a basic-based solvent system, ethylene diamine/potassium thiocyanate (EDA/KSCN) with the aid of cyclic freezing-thawing. The investigation on the characteristics of supramolecular hydrogels revealed that repeated freezing-thawing cycles played an important role in the formation of the physical cross-linked supramolecular network structure between cellulose and gelatin. The mechanical properties of supramolecular hydrogels were much higher than pure cellulose and gelatin hydrogel, and the compressive strength was 9.6 times higher than that of pure gelatin hydrogel. The synergistic effect between hydrogen-bonding interaction and the reinforcement of regenerated cellulose nanofibrils (CNF) contributed to the superior mechanical performance. Furthermore, the swelling kinetics tests showed that the supramolecular hydrogels exhibited excellent pH-responsibility, indicating potential applications in biomedical fields. Thus, a straightforward route to construct natural polymer-based hydrogels with supramolecular structure through physical crosslinking strategy without employing hazardous crosslinking agents was developed, paving the way for the design of new types of hydrogels.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2018
·
IF 6.945
Xianlin Xu,Guodong Zhao,Hang Wang,Xiaojie Li,Xi Feng,Bowen Cheng,Lei Shi,Weimin Kang,Xupin Zhuang,Yan Yin
Proton exchange membranes with remarkable performance are important for the development of direct methanol fuel cells. Inspired by the proton-conducting mechanism of transmembrane proteins, amino-acid-functionalized cellulose whiskers, are developed as a novel proton-conducting pathway for hybrid proton exchange membranes. Fmoc-amino acids are immobilized onto the surface of cellulose whiskers to obtain amino acids (Glycine, 5-amino-Valeric acid, l -Serine, l -Asparagine, and l -Leucine) functionalized cellulose whiskers with primary amino groups after Fmoc-deprotection. Proton-conducting mixed-matrix membranes are obtained by incorporating amino-acid-functionalized cellulose whiskers into sulfonated polysulfone . The performance of hybrid proton exchange membranes is evaluated to study the effects of the structure and content of amino acids. Results shows that the introduction of amino acids considerably enhances the proton conductivity . Proton exchange membranes with 4 wt.% and 10 wt.% content of l -Serine-functionalized cellulose whiskers have high proton conductivity of 0.209 S/cm and 0.234 S/cm at 80 °C, respectively. In addition, water uptake, resistance to methanol permeability and single-cell performance are also enhanced. These results indicates that the composition of filler and mixed matrix exhibit remarkable properties, and proton-conducting mixed-matrix membranes are promising materials in direct methanol fuel cells.
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2018
·
IF 5.807
Ibrahim Nasser Ahmed,Xiu-Li Yang,Amare Aregahegn Dubale,Ruo-Fei Li,Yi-Ming Ma,Lu-Ming Wang,Gui-Hua Hou,Rong-Feng Guan,Ming-Hua Xie
Developing a new cellulase-MOF composite system with enhanced stability and reusability for cellulose hydrolysis was aimed. Physical adsorption strategy was employed to fabricate two cellulase composites, and the activity of composite was characterized by hydrolysis of carboxymethyl cellulose. The NH 2 functionalized UiO-66-NH 2 MOF exhibited higher protein loading than the precursor UiO-66, due to the extra anchor sites of NH 2 groups. The immobilized cellulase showed enhanced thermostability, pH tolerance and lifetime. The maximum activity attained at 55 °C could be kept 85% when used at 80 °C, and the residual activities were 72% after ten cycles and 65% after 30 days storage. The abundant NH 2 and COOH groups of MOF adsorb cellulase and enhance its stability, and the resulted heterogeneity offered the opportunity of recovering composite via mild centrifuge. The findings suggest the promising future of developing cellulase-MOF composite with ultrahigh activities and stabilities for practical application.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Sustainable Energy & Fuels
·
2018
·Vol. 2
·期 8
·1855-1862
·
IF 0
Jiajin Liang,Jiao Chen,Shubin Wu,Chao Liu,Ming Lei
Comprehensive understanding of cellulose pyrolysis is critical to valuable chemical and liquid fuel generation in biomass-based biorefining processes. Herein, a specific tubular reactor was designed to observe the cellulose appearance alteration corresponding to the chemical structure evolution in various pyrolysis stages. The appearance of cellulose changed from white powder to light brown powder below 300 °C as its crystal lattice thermal expansion and the degree of crystallinity decrease. Cellulose began to depolymerize at 300 °C accompanied with the dehydration of pinacol and primary product levoglucosan generation. 325–350 °C was the critical pyrolysis stage for cellulose. The intermediate state was formed accompanied with a series of thermochemical reactions. All the typical signals from FTIR, 13C CP/MAS NMR disappeared when the temperature was up to 350 °C. The percentages of C, H, and O conversion to the volatile products were up to 35%, 55% and 60%, respectively, along with β-1,4-glycosidic bond cleavage, decarboxylation, and decarbonylation reactions. Meanwhile, CO2, CO, and CH4 were measured using a thermogravimetric analyzer coupled with a Fourier transform infrared spectrometer (TG-FTIR) in the slow pyrolysis process. The increasing C/H and C/O ratios in the carbonation stage enhanced the aromaticity of biochar. Furthermore, electron paramagnetic resonance (EPR) analysis indicated that it tended to form carbon-centered radicals.
✓ 已验证
产品关联
DOI
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Jiangbin Zhao,Lei Ding,Xiaofeng Sui,Zhiping Mao,Hong Xu,Yi Zhong,Linping Zhang,Zhize Chen,Bijia Wang
A general way to prepare bio-based polymer colorant by reactive dyeing of regenerated cellulose (RC) in dimethyl sulfoxide (DMSO) was established. Up to 40% higher dye utilization was achieved compared with aqueous reactive dyeing of RC for two reasons. 1. Lower liquor ratio of 1:9 could be applied for the concentrated RC suspensions in DMSO was less viscous. 2. Dye loss from solvolysis was turned off in DMSO. The method was generally applicable to RCs made from wood pulp, waste cotton, and bamboo pulp. The dyeing process has minimum influence on the morphological, rheological, and thermal properties of RC. The colored RCs thus prepared were used to prepare colored polymer composites via a Pickering emulsion approach, and to color cotton, cotton blend, and viscose fabrics via a printing approach. Therefore, it holds great potential as renewable and biodegradable pigments for making colorful composites, ink, textile dyeing and finishing.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2018
·Vol. 10
·期 10
·1049
·
IF 2.935
Yufeng Ma,Xuanang Gong,Chuhao Liao,Xiang Geng,Chunpeng Wang,Fuxiang Chu
In order to improve the performance of phenolic foam, an additive compound of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and Itaconic acid (ITA) were attached on the backbone of ethyl cellulose (EC) and obtained DOPO-ITA modified EC (DIMEC), which was used to modify phenolic resin and composite phenolic foams (CPFs). The structures of DOPO-ITA were verified by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H NMR). The molecular structure and microstructure were characterized by FT-IR spectra and SEM, respectively. Compared with EC, the crystallinity of DIMEC was dramatically decreased, and the diffraction peak positions were basically unchanged. Additionally, thermal stability was decreased andTidecreased by 24 °C. The residual carbon (600 °C) was increased by 25.7%. With the dosage of DIMEC/P increased, theEavalues of DIMEC composite phenolic resins were increased gradually. The reaction orders were all non-integers. Compared with PF, the mechanical properties, flame retardancy, and the residual carbon (800 °C) of CPFs were increased. The cell size of CPFs was less and the cell distribution was relatively regular. By comprehensive analysis, the suitable dosage of DIMEC/P was no more than 15%.Keywords:DOPO;itaconic acid;ethyl cellulose;phenolic foams;composites
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）