INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Hangcheng Zhu,Yong Zhang,Xiaogang Yang,Hongyi Liu,Xiumei Zhang,Juming Yao
A simple one-step and homogeneous synthesis method of dicarboxyl cellulose for the flocculant application is developed via Schiff base route using the cellulose from Phyllostachys heterocycla. The bamboo pulp cellulose is dissolved in NaOH–urea solution and oxidized as dialdehyde cellulose by NaIO4, which is continuously reacted with the residual urea and NaOH in the original reaction system to synthesize dicarboxyl cellulose. This one-step method greatly reduces the complexity and heterogeneity of the traditional two-step synthesis procedure, and avoids greatly the environmental pollution caused by the cellulose solvent. The dicarboxyl cellulose is characterized by Fourier transform infrared spectroscopy and X-ray diffraction spectroscopy, which exhibits an excellent coagulation–flocculation capability to kaolin suspension with a turbidity removal of 99.5%.
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CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Tian Lan,Zi-qiang Shao,Jian-quan Wang,Mu-jia Gu
This contribution, for the first time, describes the preparation and characterization of hydroxyapatite (HAp) nanoparticles decorated cellulose triacetate (CTA) nanofibers for Bovine serum albumin (BSA) adsorption. CTA as core materials and HAp nanoparticles as sheath materials were used in nanofiber preparation. The chemical and morphological structures of CTA (core)-HAp (sheath) nanofibers were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Energy dispersive spectrometer (EDS), Fourier-transform infrared spectroscopy (FTIR). The prepared composite nanofibers were applied to adsorbing Bovine serum albumin (BSA), and the maximum equilibrium adsorption capacity (from Freundlich isotherm data) for BSA was 176.04 mg/g, which was higher than CTA nanofibers (18.39 mg/g). Thus the CTA (core)-HAp (sheath) nanofibers have the potential applications in the field of protein purification.
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CARBOHYDRATE POLYMERS
·
2013
·
IF 3.479
Dong Yang,Xinwen Peng,Linxin Zhong,Xuefei Cao,Wei Chen,Xueming Zhang,Shijie Liu,Runcang Sun
Epoxidized soybean oil (ESO), which is a biomass-derived resource, was first used as a novel plasticizer for ethyl cellulose (EC) film preparation. Surface morphologies, mechanical performances, thermal properties, oxygen and water vapor permeabilities of plasticized EC films were detected in detail to evaluate the plasticizing effect of ESO and explore the plastication mechanisms. Results showed that ESO was an effective plasticizer that outstripped conventional plasticizers, i.e. dibutyl phthalate (DBP) and triethyl citrate (TEC) in producing high-quality films. Especially, at plasticizer concentrations of 15–25%, ESO–EC films had preferable mechanical properties and better thermal stability, as well as non-flammability. In addition, the water vapor permeability of ESO–EC films was lower than that of traditional plasticized films. Their oxygen permeability was also remained in a low level. These outstanding performances were related to the relatively high molecular weight, hydrophobicity, chemical structure of ESO, and the intermolecular interactions between ESO and EC chains.
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高影响因子
RSC Advances
·
2013
·Vol. 3
·期 35
·15058-15064
·
IF 2.562
Kezheng Gao,Ziqiang Shao,Xi Wang,Yunhua Zhang,Wenjun Wang,Feijun Wang
In recent years, much effort has been dedicated to achieve environmentally friendly, low cost, and excellent performance energy storage devices. In this work, cellulose nanofibers (CNFs)/multi-walled carbon nanotubes (MWCNTs) hybrid aerogels are prepared from CNFs/MWCNTs hydrogels by supercritical CO2 drying using CNFs as an effective, environmentally friendly, and steady dispersant of MWCNTs. All-solid-state flexible supercapacitors are fabricated using CNFs/MWCNTs hybrid aerogel film as the electrode material and charge collector. One-dimensional CNFs can effectively prevent the aggregation of MWCNTs, significantly enhance the re-wettability, and improve the utilization efficiency of the mesopores. Therefore, CNFs/MWCNTs hybrid aerogel film-based all-solid-state flexible supercapacitors exhibit excellent electrochemical properties: the specific capacitance is about 178 F g−1. The flexible supercapacitors also exhibit excellent cyclic stability. Our work provides a novel method using low cost, and environmentally friendly CNFs to realize the full potential of the MWCNTs in an assembled bulk form. Taking its low cost and environmentally friendliness, CNFs/MWCNTs hybrid aerogel has great potential as the electrode material for all-solid-state flexible supercapacitors.
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CELLULOSE
·
2014
·Vol. 21
·期 5
·3361-3369
·
IF 3.033
Lou Hongming,Lai Huanran,Wu Shun,Li Xiuli,Yang Dongjie,Qiu Xueqing,Huang Jinhao,Yi Conghua
The effects of long-chain fatty alcohols (LFAs) on the enzymatic hydrolysis of crystalline cellulose by two commercial Trichoderma reesei cellulase cocktails (CTec2 and Celluclast 1.5L) were studied. It was found that n -butanol inhibited the enzymatic hydrolysis, but n -octanol, n -decanol and n -dodecanol had strong enhancement on enzymatic hydrolysis of crystalline cellulose in the buffer pH range from 4.0 to 6.0. LFAs can increase the hydrolysis efficiency of crystalline cellulose from 37 to 57 % at Celluclast 1.5L loading of ten filter paper units (FPU)/g glucan. LFAs have similar enhancement on the enzymatic hydrolysis of crystalline cellulose mixed with lignin or xylan. The enhancement of LFAs increased with the decrease of the crystallinity index. LFAs not only enhanced the high-solid enzymatic hydrolysis of lignocellulose, but also improved the rheological properties of high-solid lignocellulosic slurries by decreasing the yield stress and complex viscosity. Meanwhile, LFAs can improve the enzymatic hydrolysis of cellobiose to glucose, especially at low cellulase loading.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2015
·
IF 2.912
Xujuan Huang,He Liu,Shibin Shang,Xiaoping Rao,Jie Song
Epoxidized soybean oil (ESO) grafted hydroxyethyl cellulose (HEC) was prepared via ring-opening polymerization, in which the hydroxyl groups of HEC acted as initiators and the polymeric ESO were covalently bonded to the HEC. Hydrolysis of ESO-grafted HEC (ESO-HEC) was performed with sodium hydroxide, and the hydrolyzed ESO-HEC (H-ESO-HEC) products were characterized via Fourier transform infrared (FT-IR) and 1H and 13C nuclear magnetic resonance (NMR) spectroscopies, high-temperature gel permeation chromatography (HT-GPC), and differential scanning calorimetry (DSC). The results indicated that ring-opening polymerization of ESO occurred with the hydroxyl groups of HEC as initiators. The molecular weights of the H-ESO-HEC products were varied by adjusting the mass ratio of HEC and ESO. Through neutralizing the carboxylic acid of H-ESO-HEC with sodium hydroxide, novel polymeric surfactants (H-ESO-HEC-Na) were obtained, and the effects of polymeric surfactants on the surface tension of water were investigated as a function of concentration of H-ESO-HEC-Na. The H-ESO-HEC-Na was effective at lowering the surface tension of water to 26.33 mN/m, and the critical micelle concentration (CMC) value decreased from 1.053 to 0.157 g/L with increases in molecular weights of the polymeric surfactants. Rheological measurements indicated that the H-ESO-HEC-Na solutions changed from pseudoplastic property to Newtonian with increasing shear rate.
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CELLULOSE
·
2014
·Vol. 22
·期 1
·203-214
·
IF 3.033
Qin Wang,Li Zhijun,Li Jixiang,Zhang Lihua,Liu Ruilai,Liu Haiqing
Two types of photochromic azobenzene hydroxypropyl celluloses (azo-HPCs) are prepared by homogeneous etherification of HPC with 4-(2,3-epoxypropoxy)-azobenzene and bromoethoxy-azobenzene in N,N -dimethylacetamide under mild conditions. The degree of substitution of azo moiety of azo-HPCs is tuned in the range of 0.6–1.8 by adjusting the mole ratio of azobenzene to HPC. Their chemical structures and properties are characterized by elemental analysis, infrared spectroscopy, nuclear magnetic resonance, thermogravimetric analysis, and differential scanning calorimetry. Compared to other cellulose ethers and esters with glass transition temperature (T g ) of normally larger than 100 °C, the azo-HPC derivatives display very low T g of ca. 20–40 °C. The azobenzenoxy-ethoxy-HPC is a thermotropic liquid crystal which displays cholesteric texture at 165 °C while cooling from its isotropic melt. Their solutions show almost fully reversible trans – cis – trans transition upon alternating irradiation of UV and visible light.
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CARBOHYDRATE POLYMERS
·
2014
·
IF 3.916
Huifang Ren,Buana Girisuta,Yonggui Zhou,Li Liu
Cellulose depolymerization to levulinic acid (LA) was catalyzed by acidic ionic liquids (ILs) selectively and recyclably under hydrothermal conditions. The effects of reaction temperature, time, water amount and cellulose intake were investigated. Dilution effect becomes more pronounced at lower cellulose intake, dramatically improving the yield of LA to 86.1%. A kinetic model has been developed based on experimental data, whereby a good fit was obtained and kinetic parameters were derived. The relationships between IL structure, polymeric structure and depolymerization efficiency were established, shedding light on the in-depth catalytic mechanism of IL, inclusive of acidity and hydrogen bonding ability. The LA product can be readily separated through extraction by methyl isobutyl ketone (MIBK) and IL can be reused over five cycles without loss of activity. This environmentally friendly methodology can be applied to selective production of LA from versatile biomass feedstocks, including cellulose and derivatives, glucose, fructose and HMF.
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GREEN CHEMISTRY
·
2013
·Vol. 16
·期 3
·1326-1335
·
IF 6.828
Benlian Lu,Airong Xu,Jianji Wang
As a kind of promising solvents, ionic liquids (ILs) have been used to dissolve cellulose and great progress has been made in recent years. However, the dissolution mechanism, especially the role of cations of ILs in the dissolution of cellulose, is still in debate. In this work, 13 kinds of ILs with a fixed anion [CH3COO]− but varied cationic backbones and alkyl chains have been prepared and characterized. The solubilities of cellulose in these ILs were measured at different temperatures. This allowed us to systematically study the effect of cationic structures on the cellulose dissolution at a given temperature. In order to investigate the dissolution mechanism, Kamlet–Taft parameters of these ILs in the temperature range from 25 to 65 °C and 13C NMR spectra of 1-benzyl-3-methylimidazolium acetate ([phC1mim][CH3COO]) + cellulose systems at 90 °C were also determined. It was found that acidic protons on the heterocyclic rings of the cations are essential for the dissolution of cellulose in the ILs, but the van der Waals interaction of cation with cellulose is not important. These protons may form C–H⋯O hydrogen bonds with hydroxyl and ether oxygen of cellulose to increase cellulose solubility. Cations of the ILs may also decrease cellulose solubility by strong interaction with anions or steric hindrance effect of large size group in their alkyl chains. These interactions together with strong O–H⋯O hydrogen bonds between the anion and hydroxyl protons of cellulose resulted in the disruption of the inter- and intra-molecular hydrogen bonds and thus effective dissolution of cellulose.
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Chemistry Central Journal
·
2013
·Vol. 7
·期 1
·1-5
·
IF 1.312
Liu Run-Qiang,Bai Lian-yang,Zhang Yi-Jun,Zhang Yu-Ping
Background At present, the study on the homogeneous-phase derivatization of cellulose in ionic liquid is mainly focused on its acetylation. To the best of our knowledge, there has been no such report on the preparation of cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) with ionic liquid 1-allyl-3-methyl-imidazolium chloride (AmimCl) so far.Results With ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as a reaction solvent, cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) was synthesized by the reaction of 3,5-dimethylphenyl isocyanate and soluble microcrystalline cellulose in a homogeneous phase. The synthesized CDMPC was then coated onto the surfaces of aminopropyl silica gel to prepare a chiral stationary phase (CSP). The prepared CSP was successfully used in chiral separation of seven racemic pesticides by high performance liquid chromatography (HPLC). Good chiral separation was obtained using n-hexane and different modifiers as the mobile phases under the optimal percentage and column temperature, with the resolution of metalaxyl, diniconazole, flutriafol, paclobutrazol, hexaconazole, myclobutanil and hexythiazox of 1.73, 1.56, 1.26, 1.00, 1.18, 1.14 and 1.51, respectively. The experimental results suggested it was a good choice using a green solvent of AmimCl for cellulose functionalization.Conclusion CDMPC was successfully synthesized as the chiral selector by reacting 3, 5-dimethylphenyl isocyanate with dissolved microcrystalline cellulose in a green ionic liquid of AmimCl.
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POWDER TECHNOLOGY
·
2013
·
IF 2.024
Dewen He,Cancheng Bai,Chongwen Jiang,Tao Zhou
Titanium containing MCM-41 is synthesized hydrothermally in the presence of structure-directing agent cetyltrimethylammonium bromide (CTAB). Bi- and tri-metal Fe and Zn are impregnated in these materials to improve the acid catalytic sites as well. XRD , BET nitrogen adsorption isotherm, TEM and SEM analysis confirm the presence of mesopores in the composite. The local environment of titanium incorporated into the mesoporous silicate material is investigated by FT-IR and UV–Vis spectroscopy. These results indicate the presence of active centers within the composite material Ti, Fe and Zn. The new composite materials are preliminarily tested in the hydrolysis of cellulose . All the titanium MCM-41 materials improve the conversion of cellulose, providing higher catalytic activity in hydrolysis. There is maximum sugar and 5-HMF concentration resulted from hydrolysis of cellulose with Fe/Ti-MCM-41 catalyst.
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CATALYSIS LETTERS
·
2014
·Vol. 144
·期 10
·1728-1734
·
IF 2.291
Wang Shengpei,Chen Jinzhu,Chen Limin
Abstract A multifunctional catalyst of ruthenium supported on NENU-3 [a hybrid of phosphotungstic acid (PTA) and HKUST-1] is developed. An ethylene glycol (EG) yield of 50.2 % can be directly obtained from cellulose with Ru/NENU-3 as catalyst under optimized conditions. As a multifunctional catalyst of Ru/NENU-3, the presence of both the active specie of PTA for cellulose hydrolysis and subsequent C–C bond cleavage of cellulose-derived sugars, and the active specie of Ru for glycolaldehyde hydrogenation is indispensible for the formation of EG from cellulose. Graphical Abstract
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危险品化学品经营许可证（带存储）