CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Lihua Zhang,Wentao Shi,Junqin Wang,Longming Jin,Gang Hu,Qiang Zheng,Haibo Xie,Peng Chen
Gelation and rheological behaviors of cellulose/CO 2 -based reversible ionic liquid (RIL)/DMSO solutions were investigated. The exponents of specific viscosity η sp versus concentration c were determined for wood pulp (WP) and microcrystalline cellulose (MCC) solutions. The complex viscosity acquired using oscillatory shear closely follows the steady shear viscosity, thus revealing the applicability of Cox-Merz rule. The influence of RIL content in the solvent on apparent viscosities, activation energy, intrinsic viscosities, specific viscosity-c[η] master curve, and relaxation time were also investigated. Gelation occurred in this cellulose solution system due to thermal-induced CO 2 release from the decomposition of the CO 2 -based reversible ionic liquid. The formed gel was stable in air, but re-dissolved when exposed to CO 2 , indicating the switch-on and switch-off effects of CO 2 in cellulose dissolution and gelation.
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DOI
PubMed
高影响因子
Advanced Composites and Hybrid Materials
·
2019
·Vol. 2
·期 3
·462-470
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IF 0
Dai Lin,Lu Jinshun,Kong Fangong,Liu Kefeng,Wei Huige,Si Chuanling
Development of biomass-based and some other sustainable biomedical materials is a key subject and effective approach to biomass high-value utilization. In this work, we used cellulose resources to develop a photoresponse hydrogel (PR-gel) by integrating 4arm-PEG and azobenzene into cellulose nanofibrils (CNFs). This novel PR-gel exhibited good mechanical strength (storage modulus over 10 3 Pa), structure stability, reversible recoverability between sustained step strain of 1% and 1000%, and excellent biocompatibility. Under UV irradiation ( λ = 365 nm, 10 mW/cm 2 , 10 min), the azobenzene cross-linker in PR-gel as photoswitch can cause the trans-cis isomerism and a softening effect of the hydrogel, thus realized the photo-controlled release of bovine serum albumin (BSA) (5-fold higher release rate under UV light irradiation). This work provided a new approach to design cellulose-based photoresponsive hydrogels. It is also can expand the application of cellulose-based hydrogels and some other sustainable materials in the biomedical field.
Cellulose nanofibrils-4arm-polyethylene glycol-azobenzene (PR-gel) exhibited good mechanical strength, reversible recoverability, excellent biocompatibility, and reversible photoresponse for protein release.
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DOI
Journal of Energy Chemistry
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2019
·
IF 5.162
Bin Hu,Qiang Lu,Yu-ting Wu,Wen-luan Xie,Min-shu Cui,Ji Liu,Chang-qing Dong,Yong-ping Yang
The catalytic fast pyrolysis of cellulose impregnated with phosphoric acid (H 3 PO 4 ) offers a promising method for the selective production of levoglucosenone (LGO), a valuable anhydrosugar product. However, the fundamental mechanism for selective LGO formation is unclear. Herein, quantum chemistry calculations and catalytic fast pyrolysis experiments were performed to reveal the formation mechanism of LGO in H 3 PO 4 -catalyzed cellulose pyrolysis. H 3 PO 4 significantly decreased the energy barriers of the pyrolytic reactions and altered the competitiveness of the LGO formation pathways, promoting LGO formation. Through different pathways in the non-catalytic and H 3 PO 4 -catalyzed conditions, LGO is mainly produced from the primary decomposition of glucose units of cellulose and secondary conversion of levoglucosan. The major catalytic formation pathways of LGO comprise similar reactions, with dehydration at the 3-OH + 2-H site as the rate-determining step. Importantly, secondary conversion of 1,4;3,6-dianhydro-α- d -glucopyranose is not feasible for LGO formation, in contrast to previous reports. In addition, a high degree of polymerization is beneficial for the selectivity of LGO formation in the catalytic process, because the glycosidic bond is important for the formation of the bicyclic structure (1,5- and 1,6-acetal rings).
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高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2020
·
IF 7.094
Yunxiao Liu,Lijuan Zhou,Li Wang,Xiaolong Pan,Kuntao Wang,Jie Shu,Lehuan Liu,Hui Zhang,Leyu Lin,Xinyan Shi,Alois K. Schlarb,Jianming Zhang
Owing to the advantages in storage, transportation and melt-processing, the powder form of cellulose nanocrystals (CNCs) as an attractive biomass filler is highly desired for the industrial application. Herein, by systematically tailoring the reaction conditions, we prepared the air-dried porous powder of CNCs modified with PMMA (CNCs-g-PMMA) via a green synthesis route, that is, using ceric ammonium nitrate (CAN) as an initiator in aqueous medium . Our results show that the porous powder of air-dried CNCs-g-PMMA can be easily obtained when the grafting ratio of PMMA was higher than 70 wt%. CNCs-g-PMMA porous powder demonstrates high specific surface area (47.8 m 2 /g), excellent hydrophobicity and oleophilicity properties. It therefore can be used as a filter for oil/water separation or as a highly efficient absorbing material. Moreover, benefiting from the improved thermal stability of CNCs and melt-processing character of PMMA, the porous powder of CNCs-g-PMMA has been converted to a transparent film by a simple compression molding . The as-prepared film demonstrates extraordinary UV shielding and mechanical stability upon heating. Particularly, there is an extraordinary increase in glass transition temperature of PMMA from 112.6 to 138.6 °C. This research provides a facile and green strategy to fabricate CNCs-g-PMMA porous powder, which shows industrial applications from different perspectives.
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高影响因子
Polymers
·
2020
·Vol. 12
·期 1
·158
·
IF 3.426
Yao Dou,Liguang Zhang,Buning Zhang,Ming He,Weimei Shi,Shiqing Yang,Yingde Cui,Guoqiang Yin
The development of edible films based on the natural biopolymer feather keratin (FK) from poultry feathers is of great interest to food packaging. Edible dialdehyde carboxymethyl cellulose (DCMC) crosslinked FK films plasticized with glycerol were prepared by a casting method. The effect of DCMC crosslinking on the microstructure, light transmission, aggregate structure, tensile properties, water resistance and water vapor barrier were investigated. The results indicated the formation of both covalent and hydrogen bonding between FK and DCMC to form amorphous FK/DCMC films with good UV-barrier properties and transmittance. However, with increasing DCMC content, a decrease in tensile strength of the FK films indicated that plasticization, induced by hydrophilic properties of the DCMC, partly offset the crosslinking effect. Reduction in the moisture content, solubility and water vapor permeability indicated that DCMC crosslinking slightly reduced the moisture sensitivity of the FK films. Thus, DCMC crosslinking increased the potential viability of the FK films for food packaging applications, offering a value-added product.Keywords:feather keratin;dialdehyde carboxymethyl cellulose;crosslinking;edible film
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PubMed
高影响因子
CELLULOSE
·
2019
·Vol. 27
·期 4
·2161-2172
·
IF 3.917
Song Wenqi,Zhu Min,Zhu Yanfang,Zhao Yuzhen,Yang Miaoxiu,Miao Zongcheng,Ren Huaping,Ma Qiang,Qian Liwei
An eco-friendly, low-cost, and highly efficient adsorbent based on biomass material, cellulose matrix-supported metal-organic-framework (MOF) hybrid aerogel (ZIF-67@CA), was designed and prepared by in situ growth of ZIF-67 nanoparticles on pre-synthesized chemically crosslinked cellulose aerogel. The chemical structure and surface morphology of as-prepared ZIF-67@CA were characterized by various methods. Analysis results confirmed the successful formation of a densely coated layer of ZIF-67 on the surface of the cellulosic aerogel. Owing to its large specific surface area and electrostatic attraction of ZIF-67 with methyl orange (MO), ZIF-67@CA exhibited high adsorption capacity of up to 617 mg g −1 for MO, which was more than four times higher than that of the pristine cellulose aerogel. Additionally, ZIF-67@CA could selectively separate anionic dye from the dye mixture and maintain 90% adsorptivity even after five cycles of repeated usage. Hence, this work provided a feasible solution and scalable platform for the functional design and rational manufacture of MOF-based cellulose aerogel. Moreover, the versatility of its structural design makes it a promising adsorbent material for wide application range of wastewater treatment.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Na Li,Jing Ming,Ruchao Yuan,Shuo Fan,Liu Liu,Faxue Li,Xueli Wang,Jianyong Yu,Dequn Wu
A novel schiff base (BD) containing nitrogen and silicone was prepared, and a phosphorus–nitrogen silicone flame retardant (BDD) was synthesized based on BD and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). It was found that the structure of BD changed continuously during the heating process and formed a self-cross-linking network structure at about 400 °C, while the porous fluffy shape was formed by BDD as an intumescent flame retardant. The char yields of BD and BDD at 700 °C were 62% and 38% in nitrogen, respectively. The obtained BD and BDD were blended to enhance the flame retardancy of cellulose membranes via a cooperative effect, and the properties were significantly achieved, which can be proved by the limit oxygen index (LOI), cone calorimeter test, and thermogravimetric results. The results showed that the incorporation of 25 wt % BD brought a 29% LOI, and the peak heat release rate (PHRR) was reduced to 732.2 kW/m2, in contrast with an LOI of 18% and PHRR of 1050.1 kW/m2 for pure cellulose. The addition of 25% BDD increased the LOI to 27% and decreased the PHRR to 644.9 kW/m2. The improved flame-retardant performance for cellulose membranes was primarily assigned to the synergistic effect from the physical barriers of self-cross-linking properties in the condensed phase and capturing or dilution of combustible gases by free radicals. This suggested that wielding BD as a self-crossing monomer and applying BDD as an intumescent flame retardant to achieve effective results on fire suppression had great potential for fire-safe cellulose.
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高影响因子
POLYMER JOURNAL
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2019
·Vol. 51
·期 11
·1211-1222
·
IF 2.639
Liu Guanghua,Lin Guanquan,Tan Mingyi,Zhou Hongjun,Chen Huayao,Xu Hua,Zhou Xinhua
To improve the utilization of pesticides and reduce the amount of pesticides used, sustained-release nanoparticles were prepared. Soybean protein isolate (SPI) and carboxymethyl cellulose (CMC) were modified to obtain hydrazine-modified SPI and aldehyde-modified CMC, respectively, and SPI-CMC was prepared by the condensation of hydrazine and aldehyde groups, forming a hydrazone bond. SPI-CMC was heated and loaded with avermectin (AVM) to obtain AVM/SPI-CMC. The encapsulation efficiency property, anti-ultraviolet property, sustained-release characteristics, pH responsiveness, and toxicological profiles were studied. The particles in the formulation were spherical-like, with sizes ranging between 150 and 250 nm. The encapsulation efficiency increased with the addition of SPI, which reached 44.49% when SPI was added in a mass ratio of m SPI-HYD : m CMC-ALD = 2:1. The percentage of remaining AVM in AVM/SPI-CMC was 31.47% higher than that in the AVM solution after UV irradiation for 43 h. Moreover, the nanoparticles were responsive to pH. SPI-CMC had no significant effect on the insecticidal toxicity of AVM. Environmental friendly SPI-CMC could protect and release pesticides continuously, which could improve the efficiency of pesticides.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
·
IF 3.375
Zhe Wen,Linhao Yu,Fuhang Mai,Zewei Ma,Hong Chen,Yongdan Li
The catalytic conversion of microcrystalline cellulose is examined over a niobic acid catalyst (NBO) prepared by an alkali fusion method. The catalytic activity of NBO is significantly affected by the reaction conditions and further acid treatment. The highest 5-hydroxymethylfurfural (HMF) yield of 7.0 mol % and a glucose yield of 17.7 mol % at a cellulose conversion of 54.2% are achieved at 230 °C for 2 h. The H2SO4-treated (NBS) and H3PO4-treated (NBP) samples both show greatly improved performance over NBO due to the introduction of strong acid sites and the increase in specific surface area. NBS gives a glucose yield of 26.0 mol % and an HMF yield of 14.1 mol %, while NBP exhibits a glucose yield of 21.4 mol % and an HMF yield of 15.5 mol %. NBO shows excellent recyclability for the catalytic hydrolysis of cellulose. The recovered NBS and NBP samples can be regenerated by calcination and subsequent acid treatment.
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高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 36
·20871-20877
·
IF 10.733
Wei Jia,Peiyi Wu
Solid electrolytes which could transport cations are widely used in energy-related and environmental applications. Herein, functionalized graphene oxide–cellulose nanofiber solid proton electrolytes (NPGOM-CNF) are successfully prepared. Based on 1D CNF and 2D dopamine-functionalized GO (NPGO), long-range 1D and 2D ionic nanochannels are constructed in the membranes with perfluorinated sulfonic acid resin (PFSA). The proton conductivity of NPGOM-10-CNF is as high as 0.4 S cm−1 at 80 °C and 95% RH, two times higher than that of commercialized Nafion117. The single-cell performance of the NPGOM-10-CNF-based MEA is 31% higher than that of the Nafion117-based MEA at 60 °C and 100% RH on account of higher proton conductivities and better H2 impedance ability. Besides, NPGOM-CNF membranes also possess outstanding stability in water and high methanol barrier performance, demonstrating great practical application potential.
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高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 8
·4525-4536
·
IF 3.809
Tang Lirong,Lin Fengcai,Li Tao,Cai Zhenghan,Hong Biyun,Huang Biao
Abstract With excellent biological, physical and chemical properties of cellulose nanocrystals, a novel colon-targeted drug release system was created by conjugating of model drug (tosufloxacintosilate, TFLX) with maleic anhydride cellulose nanocrystals (MCNCs), in which l -leucine was used as a spacer molecule. The satisfactory drug loading of 29.14% as well as high encapsulation efficiency of 99.84% were obtained. The hydrodynamic diameters of MCNCs, drug (TFLX) and drug conjugates are 124, 491 and 520 nm, respectively, which demonstrates that MCNCs might adhere to the surface of drug tightly. The successful linking of l -leucine to MCNCs and amidation reaction between drug and A-MCNCs were confirmed by FTIR and XPS spectra. Moreover, the release behaviors of drug conjugates and fluorescent-labeled drug conjugates in simulated fluids were investigated by in vitro study and fluorescence detection. It is found that the drug conjugates could release about 72.55% of the drug loaded in the simulated colon fluid with enzyme lysozyme after 30 h, but no drug was detected in simulated gastric fluids with enzyme pepsin. The results illustrate that the model drug could be entrapped efficiently by MCNCs and have an excellent behavior for colon-targeted release. The paper reveals that cellulose nanocrystals can be considered potential carriers in colon specific drug delivery system. Graphical abstract
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高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Qiuhong Bai,Qiancheng Xiong,Cong Li,Yehua Shen,Hiroshi Uyama
Hierarchical porous activated carbon (AC) materials were prepared from a composite of highly accessible carbon sources, sodium alginate and bacterial cellulose, by carbonization and KOH activation. The as-obtained carbon materials not only possessed rich oxygenated functionalities but also formed a hierarchical porous structure. The unique structures and chemical compositions of the resulting materials demonstrate good potential for use in supercapacitor electrode materials. The AC had a three-dimensional interconnected network structure consisting of sheet-like connected particles. Interestingly, the carbon material possessed high graphitization degree and good electrical conductivity. The electrochemical properties of electrodes were evaluated in a three-electrode system in 6 M KOH. Due to the synergistic effects of the rich oxygen content and the porous structure, the sample calcined at 700 °C showed a high gravimetric capacitance of 302 F/g, an excellent capacitance retention ratio of 75.2% at 10 A g −1 , and good cycling stability with 93.8% capacitance retention after 10,000 cycles. The as-obtained single electrode exhibited a very high energy density of 23.7 W h kg −1 , making it more interesting than commercial AC for practical applications. This study demonstrates that the utilization of abundant polymers from nature is a good route for fabricating high-performance supercapacitor electrode materials.
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高影响因子
危险品化学品经营许可证（带存储）