CELLULOSE
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2018
·Vol. 25
·期 10
·6041-6053
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IF 3.809
Yu Qian,Kong Xianming,Ma Yibo,Wang Rui,Liu Qing,Hinestroza Juan P.,Wang Alan X.,Vuorinen Tapani
Abstract Multi-functional cellulose fiber-Au composites were fabricated through a simple and cost-effective procedure by decorating regenerated cellulose fibers with Au nanoparticles. The cellulose fibers were regenerated from waste paper through the Ioncell-F process, an environmental friendly approach. After grafting positive charge, the surface of the cellulose fibers were decorated with citrate-stabilized plasmonic Au nanoparticles (NPs). X-ray photoelectron spectroscopy, scanning electron microscopy, X-ray diffraction, and optical images were used to characterize the regenerated cellulose fibers and fiber-Au NP composites. The fiber-Au composites exhibited different colors as the localized surface plasmon resonance property of Au NPs, which enables visual sensing of the water content in the fiber-Au composites through a colorimetric method. Furthermore, the regenerated cellulose fiber-Au composite was used as an enhanced substrate for the sensing of malachite green via surface-enhanced Raman scattering, in which the limit of detection was lower than 10 ppb. The multi-functional cellulose fibers are potentially suitable for the detection of toxins and the monitoring of water quality. Graphical abstract
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高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 10
·5687-5696
·
IF 3.809
Liu Shaojie,Sun Tingting,Yang Desheng,Cao Meng,Liang Huazhe
Abstract Water-soluble polyacrylic acid was prepared by solution polymerization, and then partially acylated by SOCl 2 to give a random copolymer of poly(acrylic acid- co -acryloyl chloride) (P(AA- co -AC)). Through the reaction of acyl chloride groups in P(AA- co -AC) with hydroxyl groups in 4-hydroxy-2,2,6,6-tetramethyl-piperidinooxy (4-OH-TEMPO), the water-soluble TEMPO immobilized copolymer of poly(acrylic acid- co -2,2,6,6-tetramethylpiperidinyloxy-4-yl-acrylate) (P(AA- co -TA)) with different TEMPO loadings were prepared and characterized by Fourier transform infrared spectroscopy and conductometric titration. P(AA- co -TA) was used as a recoverable catalyst instead of free TEMPO for selective catalytic oxidation of cellulose in water. The carboxyl content of oxidized cellulose with P(AA- co -TA) as catalyst was up to 60% of the free TEMPO level. Furthermore, P(AA- co -TA) was easy to recycle by its pH-sensitivity and the activity did not decrease after 4 cycles. Graphical abstract
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高影响因子
Sustainable Energy & Fuels
·
2018
·Vol. 2
·期 8
·1855-1862
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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.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2019
·
IF 4.784
Hafiz Muhammad Ahsan,Xingzhong Zhang,Yan Li,Bin Li,Shilin Liu
The phenomenon of polymer adsorption was applied to modify the surface of microcrystalline cellulose (MCC). The active polymer sodium carboxymethyl cellulose (CMCNa), having different molecular weight was used to produce modified MCCs. The average particle size of unmodified MCC was about 14.208 ± 0.064 μm, and it was increased to 19.576 ± 0.26 μm after modification. The modified MCCs exhibited a typical shear thinning behavior. It suggested that the molecular weight of active polymer had an amenable and significant influence on the physicochemical properties and stability of MCCs. The composites prepared from CMCNa with high molecular weight were more stable than others. Moreover, dried MCCs could be re-dispersed in water and could be used as a stabilizer for Pickering emulsions. The obtained emulsions (CMCNa-c) showed higher stability against pH changes, ionic strength and coalescence during storage. It suggested that the re-dispersible MCCs played a significant role in stabilization of emulsions. Furthermore, the re-dispersible MCCs preserved the original properties of un-dried composites and could also be used in other food allied sectors.
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PubMed
高影响因子
CARBOHYDRATE POLYMERS
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2019
·
IF 6.044
Guifa Xiao,Ying Wang,Hui Zhang,Liheng Chen,Shiyu Fu
Facile strategy to construct a cellulose nanocomposite hydrogel with self-healing and biocompatible properties is reported by crosslinking dialdehyde cellulose nanocrystals with acylhydrazine-terminated polyethylene glycol via dynamic reversible acylhydrazone for the first time. The effects of process variables on gelation time, mechanical strength and self-healing efficiency of hydrogels were investigated. It was found that gelation time shortened from hours to seconds by adjusting gelator and catalyst concentration. Tensile and compressive strength of hydrogel could reach 141 K Pa and 580 K Pa at 20.1% gelator concentration, respectively. Interestingly, the as-prepared hydrogel presented excellent self-healing ability without additional stimuli whose healing efficiency was higher than 90% even at higher gelator concentration. Furthermore, Cytotoxicity test showed that cell viability almost reached 100% after culturing with hydrogel, which revealed the hydrogel was biocompatible.
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PubMed
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 8
·5065-5074
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IF 3.917
Hou Ting,Guo Kechun,Wang Zhongguo,Zhang Xiong-Fei,Feng Yi,He Ming,Yao Jianfeng
Self-standing and flexible regenerated cellulose membranes were fabricated by using a facile ZnCl 2 /CaCl 2 /cellulose dissolution system. The filtration experiments of the membranes were conducted by using methyl orange and Congo red as water contaminations. To improve the selectivity and stability, the crosslinkers of glutaraldehyde and polyvinyl alcohol were introduced to the membrane network. The best performance was observed over glutaraldehyde and polyvinyl alcohol crosslinked cellulose (P-G-RC) membrane with a Congo red rejection rate of 99.9% and a methyl orange rejection rate of 93.5%. The suitable pore radius (0.67 nm), low root-mean-square roughness (2.9 nm) and abundant hydroxyl groups were considered as the primary reasons contributed to the separation behavior. Furthermore, the P-G-RC membrane displayed excellent stability and reusability during the filtration tests.
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高影响因子
POLYMER
·
2018
·
IF 3.483
Zhanjun Cai,Rui Li,Xianlin Xu,Guoguang Sun,Xupin Zhuang,Ya Liu,Bowen Cheng
Optimization of chemical composition and topography is vital to obtain high-performance proton exchange membranes (PEMs). In this work, cellulose nanofibers were incorporated with phosphoric acid and embedded into the sulfonated poly (ether sulfone) (SPES) matrix to develop PEMs with improved proton conductivity by building proton transfer channels and providing additional proton transport sites. The morphology and chemical structure of the nanofibers doped with different phosphoric acid concentrations and the performance of the composite PEMs were characterized by multi-technics. The results showed that the thermal stability, water swelling ratio (SR) and proton conductivity of the composite membrane were improved in the phosphoric acid-doped cellulose nanofibers. The maximum conductivity (0.154 S/cm, 80 °C, 100 RH) was reached for composite membranes with cellulose nanofibers doped with 0.25 mol/L phosphoric acid. Hence, composite membranes containing proton-conducting cellulose nanofibers could be used to develop novel PEMs for fuel cells.
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高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 8
·4525-4536
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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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
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
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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POLYMER JOURNAL
·
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
CARBOHYDRATE POLYMERS
·
2017
·
IF 4.811
Ximei Li,Keke Zhang,Ran Shi,Xiaomei Ma,Liwen Tan,Quan Ji,Yanzhi Xia
Magnesium oxide (MgO) microcapsules were synthesized via in-situ emulsion polymerization as confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy. Pure MgO and the MgO microcapsules were separately incorporated into cellulose fibers by blend wet spinning. Inductively coupled plasma-emission spectroscopy results revealed that cellulose fibers modified with the MgO microcapsules contained more Mg 2+ than those modified by pure MgO, indicating more acid resistance. The flammability and thermal degradation of modified cellulose fibers (cellulose-Mg fibers) were studied by calorimeter (CONE), thermogravimetry (TGA), and the determination of the limiting oxygen index (LOI). The minimal LOI value obtained for the cellulose-Mg fibers was 35, being much higher than that of the unmodified cellulose fiber (19). The heat release rate of the cellulose-Mg fibers was significantly lower than that of the non-doped ones. The TGA curves showed that the generated residues increased from 13.79% (cellulose fiber) to 30.26% (cellulose-Mg fiber).
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PubMed
高影响因子
危险品化学品经营许可证（带存储）