Polymer binder plays a pivotal role in electrochemical performance of high-capacity silicon(Si)anode that usually suffers from severe capacity fading due to enormous substantial volume change of Si during cycling.In a...Polymer binder plays a pivotal role in electrochemical performance of high-capacity silicon(Si)anode that usually suffers from severe capacity fading due to enormous substantial volume change of Si during cycling.In an effort to find efficient polymer binder that could mitigate such capacity fading,alginate-carboxymethyl chitosan(Alg-C-chitosan)composite polymer was investigated as a low-cost watersoluble binder for silicon anodes in lithium-ion batteries.The electrostatic interaction between carboxylate(-COO-)of Alg and protonated amines(-NH3+)of C-chitosan forms a selfhealing porous scaffold structure.Synergistic effect on the enhanced porous scaffold structure and self-healing electrostatic interaction of Alg-C-chitosan binder effectively can tolerate the tremendous volume change of Si and maintain an integrated electrode structure during cycling process.The Si nanopowder electrodes with Alg-C-chitosan composite binder exhibit an excellent cycling stability,with a capacity of750 mAh·g-1 remaining after 100 th cycling.In addition,an extraordinary areal capacity of 3.76 mAh·cm-2 is achieved for Si-based anodes with Alg-C-chitosan binder.展开更多
[Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan （NOA, NOB and NOC）with various degrees of substitution （D...[Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan （NOA, NOB and NOC）with various degrees of substitution （DS）were obtained by etherizing chito-oligosacchaside. Their structure and substituted degree were characterized and their antioxldant activity to·OH was evaluated. [ Result] The IC50 s of NOA ,NOB and NOC were 0.15 ,0. 29 ,0. 23 mg/ml while their DSs of -NH2 position（DSN） were 0.51,0.29 and 0.38 and DSo were 0. 74 ,0. 84 ,0. 97respectively.[ Conclusion] With the increase of DSN ,antioxidant activity of N,O-carboxymethyl chitosan oligosaccharide to·OH was up.展开更多
Removal of noxious dyes is gaining public and technological attention. Herein grafting polymerization was employed to produce a novel adsorbent using acrylic acid and carboxymethyl cellulose for dye removal. Scanning ...Removal of noxious dyes is gaining public and technological attention. Herein grafting polymerization was employed to produce a novel adsorbent using acrylic acid and carboxymethyl cellulose for dye removal. Scanning electron microscopy and Fourier-transform infrared spectroscopy verified the adsorbent formed under optimized reaction conditions. The removal ratio of adsorbent to Methyl Orange, Disperse Blue 2BLN and malachite green chloride reached to 84.2%, 79.6% and 99.9%, respectively. The greater agreement between the calculated and experimental results suggested that pseudo second-order kinetic model better represents the kinetic adsorption data. Equilibrium adsorptions of dyes were better explained by the Temkin isotherm. The results implied that this new cellulose-based absorbent had the universaiity for removal of dyes through the chemical adsorption mechanism.展开更多
In this study,three magnetic flocculants with different chelating groups,namely,carboxymethyl chitosan-modified Fe_(3)O_(4)flocculant(MC),acrylamide-grafted magnetic carboxymethyl chitosan flocculant(MCM),and 2-acryla...In this study,three magnetic flocculants with different chelating groups,namely,carboxymethyl chitosan-modified Fe_(3)O_(4)flocculant(MC),acrylamide-grafted magnetic carboxymethyl chitosan flocculant(MCM),and 2-acrylamide-2-methylpropanesulfonic acid copolyacrylamide-grafted magnetic carboxymethyl chitosan flocculant(MCAA)were prepared,synthesized,and characterized by photopolymerization technology.They were applied to the flocculation removal of Cr(Ⅲ),Co(Ⅱ),and Pb(Ⅱ).The effect of flocculation condition on the removal performance of Cr(Ⅲ),Co(Ⅱ),and Pb(Ⅱ)was studied.Characterization results show that the three magnetic carboxymethyl chitosan-based flocculants have been successfully prepared with good magnetic induction properties.Flocculation results show that the removal rates of MC,MCM,and MCAA on Cr(Ⅲ)are 51.79%,82.33%,and 91.42%,respectively,under the conditions of 80 mg/L flocculant,pH value of 6,reaction time of 1.5 hr,G value of 200 s^(-1),and precipitation magnetic field strength of 120 mT.The removal rates of Co(Ⅱ)by MC,MCM,and MCAA are 54.33%,84.99%,and 90.49%,respectively.The removal rates of Pb(Ⅱ)by MC,MCM,and MCAA are 61.54%,91.32%,and 95.74%,respectively.MCAA shows good flocculation performance in composite heavy metal-simulated wastewater.The magnetic carboxymethyl chitosan-based flocculant shows excellent flocculation performance in removing soluble heavy metals.This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove heavy metals in wastewater.展开更多
We prepared spherical microcapsules modified by carboxymethyl cellulose（CMC） with urea-formaldehyde（UF） resin as a shell material with a two-step process by in situ polymerization, and characterized the microcosmi...We prepared spherical microcapsules modified by carboxymethyl cellulose（CMC） with urea-formaldehyde（UF） resin as a shell material with a two-step process by in situ polymerization, and characterized the microcosmic features, chemical structure, and thermal performance of the microcapsules by SEM, FTIR, DSC, and TGA. We studied the effects of different experimental parameters of curing p H, the amounts of the emulsifier and emulsion speed. The CMC-UF microcapsules had good heat resistance and stability. The enthalpy of CMC-UF microcapsules reached 50.33 J g-1. Therefore, CMC-UF resin can be used as a potential wall material of phase change materials.展开更多
Carboxymethyl chitosan–hemicellulose resin（CMCH） was synthesized by thermal cross-linking process and characterized by FTIR, TGA, and SEM. Subsequently, the adsorption properties of CMCH toward Ni（Ⅱ）,Cd（Ⅱ）, C...Carboxymethyl chitosan–hemicellulose resin（CMCH） was synthesized by thermal cross-linking process and characterized by FTIR, TGA, and SEM. Subsequently, the adsorption properties of CMCH toward Ni（Ⅱ）,Cd（Ⅱ）, Cu（Ⅱ）, Hg（Ⅱ）, Mn（Ⅶ） and Cr（Ⅵ） were evaluated. Various factors affecting the uptake behavior such as pH, temperature, contact time and the initial concentration of the metal ions were investigated.The results showed that all adsorption processes fit the pseudo-second-order model and Langmuir isotherm equation. Significantly, the regeneration experiments showed CMCH can be used as a potentially recyclable and effective adsorbent for the removal and recovery of metal ions from wastewater.展开更多
A cellulase producing bacterium (E3 strain) was isolated from fecal matter of elephant and identified as Bacillus sp. using 16S rDNA sequenced based molecular phylogenetic approach. While studying the effect of substr...A cellulase producing bacterium (E3 strain) was isolated from fecal matter of elephant and identified as Bacillus sp. using 16S rDNA sequenced based molecular phylogenetic approach. While studying the effect of substrates like Carboxymethyl cellulose (CMC), avicel, starch, maltose, sucrose, glucose, fructose, galactose and lactose on cellulase production, it was found that CMC was best carbon source induced cellulase production followed by lactose in this bacterial strain. A positive synergistic effect of lactose with CMC was also observed with enhancement of 5 - 6 times in cellulase production. The optimum cellulase production was recorded with 1% CMC and 1% lactose when added individually in the Omeliansky’s medium. The results showed that addition lactose with CMC greatly enhances the production and activity of various cellulase enzymes. The optimal fermentation conditions for the biosynthesis of cellulase by this strain were found to be temperature: 37℃, pH 7.0. The nitrogen source NH4Cl at 0.15% was optimum for cellulase production by this bacterium.展开更多
Silicon anodes have drawn ever-increasing attention in lithium-ion batteries(LIBs) owing to their extremely high theoretical capacity and abundance in the earth. Despite promising advantages, the wide use of silicon a...Silicon anodes have drawn ever-increasing attention in lithium-ion batteries(LIBs) owing to their extremely high theoretical capacity and abundance in the earth. Despite promising advantages, the wide use of silicon anodes in LIBs is highly hindered by their fast capacity fading and low Coulombic efficiency arising from their substantial volumetric variation(>300%). Herein, we report a novel aqueous hybrid gel binder for silicon anodes via crosslinking sodium carboxymethyl cellulose(NaCMC) by an inorganic crosslinker-sodium borate. Not only this gel polymer binder can chemically bond to silicon nanoparticle, but also the deformable framework of this crosslinked binder is capable of maintaining electrode integrity, thus buffering dramatic volume change of silicon. Consequently, the silicon anode with this gel binder exhibits good cycle life(1211.5 mAh/g after 600 cycles) and high initial Coulombic efficiency(88.95%).展开更多
The present study aimed to compare the clinical efficacy of a 0.4% carbomer gel and 1% carboxymethyl cellulose （CMC） containing artificial tears in treatment of dry eye patients. Sixty subjects with mean age of 45.8...The present study aimed to compare the clinical efficacy of a 0.4% carbomer gel and 1% carboxymethyl cellulose （CMC） containing artificial tears in treatment of dry eye patients. Sixty subjects with mean age of 45.89 years who had symptoms and signs of dry eye were enrolled in this prospective, investigator-masked and stratified random sampling study. The subjects were divided into two parallel groups with 30 subjects （60 eyes） in each group. One group received carbomer gel, and the other group received 1% CMC containing artificial tears. Subjects received the drops 3 to 4 times or more per day for 3 months. At the first visit time, the precorneal residence time of these two drops was measured. The efficacy was assessed by comparing the subjective symptoms （ocular dry- ness, foreign body sensation, burning sensation and pain）, and the objective test results of tears breakup time, Schirmer＇s test and corneal fluorescein staining prior to the study and after the treat- ment. As a result, the ocular residence time of carbomer gel was significantly longer than that of 1% CMC （P〈0.001）. Most of the primary subjective symptoms and objective test results were improved after treatment in both carbomer gel group and 1% CMC group. As to the improvement of each symptom and objective test result, carbomer gel was more effective than 1% CMC group （P〈0.01）. In conclusion, carbomer gel had longer precorneal residence time and was more effective than 1% CMC in the treatment of patients with dry eyes.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51404032)the National High Technology Research and Development Program of China(No. 2013AA050904)
文摘Polymer binder plays a pivotal role in electrochemical performance of high-capacity silicon(Si)anode that usually suffers from severe capacity fading due to enormous substantial volume change of Si during cycling.In an effort to find efficient polymer binder that could mitigate such capacity fading,alginate-carboxymethyl chitosan(Alg-C-chitosan)composite polymer was investigated as a low-cost watersoluble binder for silicon anodes in lithium-ion batteries.The electrostatic interaction between carboxylate(-COO-)of Alg and protonated amines(-NH3+)of C-chitosan forms a selfhealing porous scaffold structure.Synergistic effect on the enhanced porous scaffold structure and self-healing electrostatic interaction of Alg-C-chitosan binder effectively can tolerate the tremendous volume change of Si and maintain an integrated electrode structure during cycling process.The Si nanopowder electrodes with Alg-C-chitosan composite binder exhibit an excellent cycling stability,with a capacity of750 mAh·g-1 remaining after 100 th cycling.In addition,an extraordinary areal capacity of 3.76 mAh·cm-2 is achieved for Si-based anodes with Alg-C-chitosan binder.
基金Supported by Shanghai Leading Academic Discipline(Project No.T1102)Shanghai Commission of Education Scientific Research Project(07zz134)~~
文摘[Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan （NOA, NOB and NOC）with various degrees of substitution （DS）were obtained by etherizing chito-oligosacchaside. Their structure and substituted degree were characterized and their antioxldant activity to·OH was evaluated. [ Result] The IC50 s of NOA ,NOB and NOC were 0.15 ,0. 29 ,0. 23 mg/ml while their DSs of -NH2 position（DSN） were 0.51,0.29 and 0.38 and DSo were 0. 74 ,0. 84 ,0. 97respectively.[ Conclusion] With the increase of DSN ,antioxidant activity of N,O-carboxymethyl chitosan oligosaccharide to·OH was up.
基金financially supported by the National Natural Science Foundation of China(No.21104047)the Outstanding Young Innovative Fund of Xinjiang Bingtuan,China(No.2010JC25)
文摘Removal of noxious dyes is gaining public and technological attention. Herein grafting polymerization was employed to produce a novel adsorbent using acrylic acid and carboxymethyl cellulose for dye removal. Scanning electron microscopy and Fourier-transform infrared spectroscopy verified the adsorbent formed under optimized reaction conditions. The removal ratio of adsorbent to Methyl Orange, Disperse Blue 2BLN and malachite green chloride reached to 84.2%, 79.6% and 99.9%, respectively. The greater agreement between the calculated and experimental results suggested that pseudo second-order kinetic model better represents the kinetic adsorption data. Equilibrium adsorptions of dyes were better explained by the Temkin isotherm. The results implied that this new cellulose-based absorbent had the universaiity for removal of dyes through the chemical adsorption mechanism.
基金supported by the Natural Science Foundation of Jiangsu Province in China(No.BK20201362)2018 Six Talent Peaks Project of Jiangsu Province(No.JNHB-038)。
文摘In this study,three magnetic flocculants with different chelating groups,namely,carboxymethyl chitosan-modified Fe_(3)O_(4)flocculant(MC),acrylamide-grafted magnetic carboxymethyl chitosan flocculant(MCM),and 2-acrylamide-2-methylpropanesulfonic acid copolyacrylamide-grafted magnetic carboxymethyl chitosan flocculant(MCAA)were prepared,synthesized,and characterized by photopolymerization technology.They were applied to the flocculation removal of Cr(Ⅲ),Co(Ⅱ),and Pb(Ⅱ).The effect of flocculation condition on the removal performance of Cr(Ⅲ),Co(Ⅱ),and Pb(Ⅱ)was studied.Characterization results show that the three magnetic carboxymethyl chitosan-based flocculants have been successfully prepared with good magnetic induction properties.Flocculation results show that the removal rates of MC,MCM,and MCAA on Cr(Ⅲ)are 51.79%,82.33%,and 91.42%,respectively,under the conditions of 80 mg/L flocculant,pH value of 6,reaction time of 1.5 hr,G value of 200 s^(-1),and precipitation magnetic field strength of 120 mT.The removal rates of Co(Ⅱ)by MC,MCM,and MCAA are 54.33%,84.99%,and 90.49%,respectively.The removal rates of Pb(Ⅱ)by MC,MCM,and MCAA are 61.54%,91.32%,and 95.74%,respectively.MCAA shows good flocculation performance in composite heavy metal-simulated wastewater.The magnetic carboxymethyl chitosan-based flocculant shows excellent flocculation performance in removing soluble heavy metals.This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove heavy metals in wastewater.
基金financially supported by the Central University Basic Scientific Research Project of China(No.2572014DB01)
文摘We prepared spherical microcapsules modified by carboxymethyl cellulose（CMC） with urea-formaldehyde（UF） resin as a shell material with a two-step process by in situ polymerization, and characterized the microcosmic features, chemical structure, and thermal performance of the microcapsules by SEM, FTIR, DSC, and TGA. We studied the effects of different experimental parameters of curing p H, the amounts of the emulsifier and emulsion speed. The CMC-UF microcapsules had good heat resistance and stability. The enthalpy of CMC-UF microcapsules reached 50.33 J g-1. Therefore, CMC-UF resin can be used as a potential wall material of phase change materials.
基金supported by the National Natural Science Foundation of China(No.21403091)the Natural Science Foundation of Jiangsu Province,China(No.BK20130486)+2 种基金Jiangsu Planned Projects for Postdoctoral Research Funds(No.1601066B)a Project Funded by Jiangsu University for Senior Intellectuals(Nos14JDG128 and 12JDG093)supporting this project under the innovation/entrepreneurship program (Surencaiban[2015]26).
文摘Carboxymethyl chitosan–hemicellulose resin（CMCH） was synthesized by thermal cross-linking process and characterized by FTIR, TGA, and SEM. Subsequently, the adsorption properties of CMCH toward Ni（Ⅱ）,Cd（Ⅱ）, Cu（Ⅱ）, Hg（Ⅱ）, Mn（Ⅶ） and Cr（Ⅵ） were evaluated. Various factors affecting the uptake behavior such as pH, temperature, contact time and the initial concentration of the metal ions were investigated.The results showed that all adsorption processes fit the pseudo-second-order model and Langmuir isotherm equation. Significantly, the regeneration experiments showed CMCH can be used as a potentially recyclable and effective adsorbent for the removal and recovery of metal ions from wastewater.
文摘A cellulase producing bacterium (E3 strain) was isolated from fecal matter of elephant and identified as Bacillus sp. using 16S rDNA sequenced based molecular phylogenetic approach. While studying the effect of substrates like Carboxymethyl cellulose (CMC), avicel, starch, maltose, sucrose, glucose, fructose, galactose and lactose on cellulase production, it was found that CMC was best carbon source induced cellulase production followed by lactose in this bacterial strain. A positive synergistic effect of lactose with CMC was also observed with enhancement of 5 - 6 times in cellulase production. The optimum cellulase production was recorded with 1% CMC and 1% lactose when added individually in the Omeliansky’s medium. The results showed that addition lactose with CMC greatly enhances the production and activity of various cellulase enzymes. The optimal fermentation conditions for the biosynthesis of cellulase by this strain were found to be temperature: 37℃, pH 7.0. The nitrogen source NH4Cl at 0.15% was optimum for cellulase production by this bacterium.
基金supported by the National Natural Science Foundation of China(No.51602250)Thousand Youth Talents Plan Project of China
文摘Silicon anodes have drawn ever-increasing attention in lithium-ion batteries(LIBs) owing to their extremely high theoretical capacity and abundance in the earth. Despite promising advantages, the wide use of silicon anodes in LIBs is highly hindered by their fast capacity fading and low Coulombic efficiency arising from their substantial volumetric variation(>300%). Herein, we report a novel aqueous hybrid gel binder for silicon anodes via crosslinking sodium carboxymethyl cellulose(NaCMC) by an inorganic crosslinker-sodium borate. Not only this gel polymer binder can chemically bond to silicon nanoparticle, but also the deformable framework of this crosslinked binder is capable of maintaining electrode integrity, thus buffering dramatic volume change of silicon. Consequently, the silicon anode with this gel binder exhibits good cycle life(1211.5 mAh/g after 600 cycles) and high initial Coulombic efficiency(88.95%).
文摘The present study aimed to compare the clinical efficacy of a 0.4% carbomer gel and 1% carboxymethyl cellulose （CMC） containing artificial tears in treatment of dry eye patients. Sixty subjects with mean age of 45.89 years who had symptoms and signs of dry eye were enrolled in this prospective, investigator-masked and stratified random sampling study. The subjects were divided into two parallel groups with 30 subjects （60 eyes） in each group. One group received carbomer gel, and the other group received 1% CMC containing artificial tears. Subjects received the drops 3 to 4 times or more per day for 3 months. At the first visit time, the precorneal residence time of these two drops was measured. The efficacy was assessed by comparing the subjective symptoms （ocular dry- ness, foreign body sensation, burning sensation and pain）, and the objective test results of tears breakup time, Schirmer＇s test and corneal fluorescein staining prior to the study and after the treat- ment. As a result, the ocular residence time of carbomer gel was significantly longer than that of 1% CMC （P〈0.001）. Most of the primary subjective symptoms and objective test results were improved after treatment in both carbomer gel group and 1% CMC group. As to the improvement of each symptom and objective test result, carbomer gel was more effective than 1% CMC group （P〈0.01）. In conclusion, carbomer gel had longer precorneal residence time and was more effective than 1% CMC in the treatment of patients with dry eyes.
