Science China-Materials
·
2021
·Vol. 65
·期 3
·721-731
·
IF 8.273
Xu Hui,Jin Meng,Geng Jing,Zhang Shengbo,Zhang Haimin
The decentralized production of H 2 O 2 via a two-electron oxygen reduction reaction (2e − ORR) has emerged as a promising alternative to the energy-intensive anthraquinone (AQ) process. However, its practical application requires 2e − ORR electrocatalysts with high activity and selectivity. Herein, we report the synthesis of metallic Ni nanoparticles anchored on bacterial cellulose-derived carbon fibers (Ni-NPs/BCCF) via a facile impregnation-pyrolysis method as efficient electrocatalysts for 2e − ORR to H 2 O 2 . By tuning the amount of Ni precursor, the best electrocatalytic performance toward 2e − ORR was achieved for Ni-NPs/BCCF-20.7, affording a high H 2 O 2 selectivity of ∼90% and an onset potential of 0.75 V vs. reversible hydrogen electrode (RHE) in an alkaline electrolyte. Ni-NPs/BCCF-20.7 achieved the largest H 2 O 2 yield rate of 162.7 ± 13.7 mmol g cat −1 h −1 and the highest Faradaic efficiency of 93.9% ± 4.2% at 0.2 and 0.5 V vs. RHE from the bulk ORR system, respectively. Theoretical calculations revealed the more favorable “end-on” adsorption configuration of molecular oxygen on the exposed Ni(111) plane, which can effectively suppress the O-O bond dissociation, resulting in high selectivity for H 2 O 2 generation.
研究领域:
材料化学
·
电化学
·
纳米催化
·
能源科学
·
环境工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 55
·34461-34465
·
IF 3.108
Tingting Zheng,Ang Li,Zhanying Li,Wenbin Hu,Lin Shao,Lingbin Lu,Yang Cao,Yongjun Chen
As an environmentally friendly aerogel with outstanding performances, the improvement of mechanical properties is urgently required for cellulose aerogel development. In this study, a cellulose aerogel with good mechanical properties was successfully fabricated using nanocrystalline cellulose (NCC) as reinforcer. Characterization results demonstrated that NCC was embedded well into the cellulose aerogel. Tests and evaluation showed that the compressive modulus of the NCC reinforced cellulose aerogel was significantly improved, about 6 times higher than that of the pure cellulose aerogel. Furthermore, after modification with trimethylchlorosilane via a cold plasma treatment, the NCC reinforced aerogel became hydrophobic but its oleophilic property remained. This aerogel showed good adsorption capacity, reached saturation rapidly and possessed good reusability. Reinforced mechanical properties with NCC make this cellulose aerogel a very promising material for highly efficient separation and extraction of organic pollutants and oils from water.
研究领域:
材料科学
·
高分子化学
·
环境功能材料
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纳米复合材料
·
绿色材料
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Yuanfeng Pan,Jingchun Wang,Pingxiong Cai,Huining Xiao
In this work, the stepwise synthesis of interpenetrating polymer network (IPN) strategy was developed in an attempt to fabricate novel hydrogels consisting of sugarcane bagasse cellulose (SBC), carboxymethylcellulose (CMC) and poly (N-isopropylacrylamide) (PNIPAm) as a dual-responsive drug carrier. The pretreated and dissolved SBC was pre-crosslinked using epichlorohydrin in the presence of CMC, followed by in-situ free-radical polymerization of NIPAm in the presence of N,N′-Methylene-bis(acrylamide) as a crosslinking agent. The carboxyl groups in CMC and PNIPAm chains rendered the resulting hydrogel pH and thermal responsive. The results from scanning electron microscopy, infrared spectroscopy , thermogravimetric analysis and mechanical property testing demonstrated the successful formation of the IPN with proper structure and mechanical strength . The swelling experiments at different temperatures and pH showed the dual–sensibility of the hydrogels. Moreover, bovine serum albumin (BSA) was used as a model drug and loaded in the hydrogel; and the drug release behavior was revealed in phosphate buffer solution (PBS) and simulated gastric fluid (SGF). The results indicated that the dual-responsive IPN hydrogel is of great potential for the controlled release of drug.
研究领域:
高分子材料
·
药物递送
·
生物医学工程
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智能响应材料
·
药剂学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 29
·16754-16766
·
IF 3.049
Jinhao Xu,Binjie Xin,Zhuoming Chen,Yan Liu,Yuansheng Zheng,Fuli Zhang
Directional water transport in garment materials plays a pivotal role in maintaining human thermal and wet comfort. In the present work, a new type of multilayer fibrous mat with the specific function of directional water transport was prepared via the combination of melt-electrospinning and solution-electrospinning. The polypropylene (PP) fibrous layer prepared by melt-electrospinning technology was located in the inner layer (next to the skin), while the polyacrylonitrile-containing hydrophilic nano-silica particles (PAN-SiO2) layer with remarkable hydrophilicity was located in the outer layer, which could effectively transport water to the outer surface of the composites. Treatment of the as-prepared PAN-SiO2/PP with an alkaline aqueous solution of dopamine not only increased the wettability of the PP layer, but also further improved the hydrophilicity of PAN-SiO2. A layer of cotton woven mesh was added between the TPP layer and TPAN-SiO2 to form a sandwich structure in order to accelerate water transport in the bilayered fibrous mats. The directional water transport, mechanical flexibility, and permeability of the prepared multilayered superfine fibrous mat were characterized systematically. The experimental results exhibited that TPAN-SiO2/cotton mesh/TPP exhibited an excellent accumulative one-way transport index (AOTI, 1071%), remarkable overall moisture management capacity (OMMC, 0.88), and reasonably high water vapor transport rate (WVT, 11.6 kg d−1 m−2), indicating it is a promising candidate for the development of novel textile materials for use in the field of sportswear for fast sweat release applications.
研究领域:
纺织材料科学
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生物医学工程
·
功能材料
·
高分子材料
·
表面改性
·
湿传递性能
·
柔性电子器件基材
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 139
·期 12
·51827
·
IF 3.125
Yuan Li,Lu Zhang,Fayong Li,Ke Wang,Xiaoru Wu,Hailu Liu,Bibo Long,Yang Zhao,Dong Xie,Junjia Chen
The hydrophobic modification of cellulose nanofibers (CNF) was carried out via free radical polymerization using methyl methacrylate (MMA) as the monomer to improve the compatibility between CNF and poly lactic acid (PLA). Followed by the preparation of the novel nanocomposites in combination of the organic montmorillonite and the substrate. The resulting nanocomposites were then coated on paper surface using a cast-coating process in an attempt to improve the barrier properties towards water vapor and oxygen. In addition, the composite films are prepared via a solution casting method. The water vapor transmission rate (WVTR), water vapor permeability (WVP), oxygen transmission rate (OTR), and tensile strength of the as-prepared films were systematically measured. The corresponding results demonstrated that the WVTR, WVP and OTR decreased with the addition of a certain content of MCNF in coatings. 0.2 wt% MCNF is the optimum content, showing the best gas resistance and tensile performance. The lowest value of WVTR and WVP are 10.30 g/(m 2 ⋯24 h) and 3306.58 g⋯μm/(m 2 ⋯24 h) for films with 0.2 wt% MCNF added, which is 88.23% and 26.05% lower than that of PLA composite film without NFC.
研究领域:
高分子材料
·
纳米复合材料
·
包装材料
·
表面涂层
·
生物基材料
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Likai Hou,Zhongjun Liang,Xu Fan,Jian Yu,Fubing Bao
Many soft coiled actuators are mimic the desirable structures of plant tendril. Here, we present a facile microfluidic spinning method to fabricate self-coiling Janus microfiber actuator with tunable morphology, spontaneous coiling performance and reversible traction property. By adjusting the component of hydrogel Janus fiber in a microfluidic spinning device with theta-shaped channels, tens of hundreds of homogeneous coils can be spontaneously and rapidly generated due to asymmetric contraction upon dehydration process, and three different forms of coiled fibers with various screw diameters are presented. Furthermore, the coiled Janus microfiber with hygroscopic properties possesses a reversible coiling/uncoiling performance under humidity gradients, which can serve as a micro-actuator to lift a certain weight with enough tensile strain and long-range tractive displacement. In addition, local reversible coiling/uncoiling morphing is achieved under water contact and near infrared light optothermal stimulations. As a verification of this coiled microfiber actuator, a smart switch is designed to control different colored LED lights for sensing an ambient moisture content.
研究领域:
生物医学工程
·
软体机器人
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功能高分子材料
·
微纳制造
·
生物传感器
·
刺激响应材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 1
·377-388
·
IF 3.049
Tianyu Wu,Wenqing Zhang,Xin Jin,Xiangyi Liang,Gang Sui,Xiaoping Yang
Carbon fiber-reinforced polymer composites have been widely used in various fields and have inevitably produced large amounts of composite waste. The recycling of carbon fibers with high value has become an active research topic at related institutions and production enterprises. In this paper, the catalytic pyrolysis of T700 carbon fiber/epoxy composites in molten salt was studied. Due to the efficient solubility of molten ZnCl2 for the epoxy matrix and catalytic fracture of the C–N bonds by the action of Zn2+ ions, the epoxy composites can be completely degraded at 360 °C in 80 min under standard pressure, and the reclamation efficiency was significantly enhanced compared with conventional pyrolysis reclamation without a catalyst. The types and contents of the main oxygen-containing functional groups on the surfaces of the fibers reclaimed with ZnCl2 were similar to those of the virgin fibers, and the graphitization structure of the carbon fibers was not destroyed in the pyrolysis process. The tensile strength of a monofilament of the fibers reclaimed with ZnCl2 was obviously higher than that of fibers reclaimed in air; it reached a high retention rate that was about 95% that of the virgin fibers. The fibers reclaimed with ZnCl2 after sizing exhibited a desirable reinforcing effect on the flexure performance and interlaminar shear strength of unidirectional carbon fiber/epoxy composites which was close to the performance levels of composite samples containing commercial T700 carbon fibers. Therefore, efficient technology to reclaim high-quality carbon fibers from epoxy matrices has been devised.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2019
·
IF 2.121
Hui Yu,Xiaojing Chen,Jie Cai,Dongdong Ye,Yuxiao Wu,Peifeng Liu
Long-term antibacterial medical dressings can prevent infection as skin wounds heal. In this study, we used the hydrophobic antibacterial drug amoxicillin as a model to prepare drug-loaded nanomicelles using a film dispersion–hydration method, and drug-loaded nanomicelles were coaxially electrospun into nanofiber to create a novel nanomicelle-in-nanofiber (NM-in-NF) drug delivery system. Scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of nanomicelles and nanofibers. Thermal property of as-prepared samples was tested using differential scanning calorimetry. The drug release behavior, cytotoxicity, and antibacterial properties of NM-in-NFs were examined in vitro to evaluate the system’s potential to be used in the treatment of skin wounds. Experimental results indicated that the novel NM-in-NF system had dual controlled release effect, which greatly reduced burst release and prolonged effective drug duration. Moreover, NM-in-NFs was also found to be safe and non-toxic, with a broad-spectrum antibacterial activity. It thus could potentially be used in long-term antibacterial medical dressings to treat skin wounds.
研究领域:
药学
·
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Dawang Chu,Chen Zhao
The effective and selective conversion of cellulose to valuable fuels and chemicals is highly attractive. In this paper, we prepared a catalyst with the adjacent surface Cu° and oxygen-deficient WO x (2 < x < 3) species by reduction of CuWO 4 precursor, and such catalyst coupled with Ni/activated carbon (AC) attained high yield (71 wt%) and good cycling performances in catalyzing one-step hydrothermal conversion of cellulose to ethylene glycol (EG), highly superior to the performances on physically mixed Ni/C, Cu/C and WO 3 . The increased Cu doping amounts led to a higher ratio of the lower valence state W (V or IV) to the high valence W(VI) as indicated by XPS, XRD, and TPR-H 2 analyses. The oxygen vacancies on the hydrogen-reduced CuWO 4 sample dramatically increased, probably due to the benefits from the substantial dissociated H• on the neighboring Cu° center. The EG yields from cellulose are shown to be proportional to the concentrations of oxygen vacancies on WO x , which catalyzes the important elementary retro-aldol step reaction via adsorbing C 6 sugar intermediates in a specific way. It is inferred that Cu introduction is mainly used to create more oxygen vacancies on the WO x surface that helps adsorbing oxygenates, while Ni fast hydrogenates of hydroxyacetaldehyde to EG and avoids coking, constructing a multi-functional synergistic catalytic process from converting of cellulose to EG in the high-temperature water
研究领域:
催化化学
·
生物质转化
·
绿色化学
·
材料化学
·
能源化学
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 3
·1577-1593
·
IF 3.917
Jiang Yan,Liu Xiuyu,Yang Qiang,Song Xueping,Qin Chengrong,Wang Shuangfei,Li Kecheng
Abstract This study investigated effects of residual lignin on composition, structure and properties of cellulose fibrils and cellulose fibril-based films by comparing two groups of cellulose fibrils which contained different amounts of lignin (15% and 2%, respectively) but were similar in cellulose to hemicellulose ratio. The results showed that lignin affected the size and content of nanofibril in cellulose fibrils through initially delaying but ultimately facilitating the mechanical defibrillation. Due to higher thermal stability and strong UV absorption capability, lignin enhanced the thermal stability and UV blocking properties of cellulose fibril-based film. Hydrophobic lignin also improved the dewatering of cellulose fibrils and the hydrophobicity of cellulose fibril-based film. Lignin interfered with the interfibrillar hydrogen bonding and therefore increased the mesopore diameter of cellulose fibril network. Lignin acting as a cement in cellulose fibril-based film made the film with a more densely packed structure, a higher density and a smoother surface. However, lignin decreased the transparency of cellulose fibril-based film due to its chromophore groups and impaired the mechanical strength of cellulose fibril-based film through interfering with the interfibrillar hydrogen bonding. Graphical abstract
研究领域:
材料科学
·
植物学
✓ 已验证
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Nan Li,Sufeng Zhang,Yali Liu,Valentin Nica,Sergiu Coseri
Cellulose-based materials are currently considered prime candidates for replacing petrochemical plastics because they are biodegradable and cost-effective, while the insufficient hydrophobicity makes them fail to meet application demands, which is a primary issue to be addressed. This work developed a green, catalyst-free approach to prepare high-hydrophobicity amidated cellulose (ADC) by anchoring the COOH-containing oleic acid (OLA) onto NH 2 -containing aminated cellulose (AMC) via amide bonds. The unsaturated fatty acid tail provides a hydrophobic barrier in ADC films . The surface water contact angle of the ADC film reached 133° and remained above 110° for at least one hour. Subsequently, the ADC suspension was applied on the surface of paper from old corrugated container (P-OCC) by an impregnation approach to investigate the improvement of hydrophobic properties. The results showed that the hydrophobicity of P-OCC was increased by ADC, with the water contact angle reached to 132° from 0°. Noticeably, the tensile strength of the ADC impregnated P-OCC (A-POCC) also increased by 2 times. This indicates that with excellent hydrophobicity and mechanical strength , the ADC has great potential application in green functional coating materials.
研究领域:
高分子材料科学
·
表面与界面化学
·
生物质功能材料
·
绿色化学
·
包装材料工程
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 3
·1961-1976
·
IF 3.917
Sun Lijian,Ding Chunyue,Qian Xueren,An Xianhui
Abstract An efficient and simple way to generate “clickable” cellulose modules called alkyne-functionalized cellulose fibers (ACFs) for click reaction was presented. This method is only based on one step reaction: propargyl methacrylate (PMA) with pendant alkynyl groups was grafted onto the surface of cellulose fibers (CFs) using ceric ammonium nitrate as the initiator in aqueous medium. This has been providing a new and versatile platform for the wide utilization of cellulose resources and creation of novel functional materials. The effect of process variables on grafting copolymerization of PMA was investigated and suitable preparation conditions were identified. The clickability of ACFs was evaluated by reacting with two azides. The antibacterial cellulose functional material was achieved through incorporation of a “clickable” handle (alkynyl groups) to cellulose fibers followed by rapid attachment of β-cyclodextrin with an azide tag using copper-catalyzed click reaction and loading with ciprofloxacin hydrochloride (CipHCl). Pure CFs and ACFs showed a little affinity to CipHCl, whereas click products (ACFs@Azide-β-CD) increased the loading amount dramatically because the equilibrium amount was higher than pure CFs and ACFs. Meanwhile, the release process of CipHCl from ACFs@Azide-β-CD was prolonged to reaches the equilibrium. The ACFs@Azide-β-CD loaded with CipHCl showed excellent antibacterial activity against Escherichia coli . The ACFs@Azide-β-CD loading CipHCl have considerably longer bacterial activity against E. coli compared to CFs and ACFs. Graphical abstract
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）