REACTIVE & FUNCTIONAL POLYMERS
·
2016
·
IF 2.725
Guanghua He,Wanwan Ke,Xiang Chen,Yahui Kong,Hua Zheng,Yihua Yin,Weiquan Cai
Quaternary ammonium chitosan- g -poly(acrylic acid- co -acrylamide) superabsorbent hydrogels were successfully synthesized from acrylic acid (AA), acrylamide (AM) and quaternary ammonium chitosan with high substitution degree. They were prepared using potassium persulfate (KPS) as an initiator and N , N ′-methylenebisacrylamide (MBA) as a crosslinker respectively. The structure and morphology of the superabsorbent hydrogel were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The water absorbency and antibacterial activities of the superabsorbent hydrogels against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) were investigated. The introduction of quaternary ammonium chitosan made the antibacterial activity improve. The crosslinker, initiator and AM contents had certain influences on the water absorbency as well as the antibacterial activity against E. coli . The AM could enhance the hydrogel strength apparently. In addition, the AM (the content was 10 wt%) could increase the water absorbency in 0.9 wt% NaCl solution obviously. The superabsorbent hydrogel also had pH sensitive property.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2016
·
IF 5.267
Jianhong Ma,Guiyin Zhou,Lin Chu,Yutang Liu,Chengbin Liu,Shenglian Luo,Yuanfeng Wei
A ethylenediaminetetra-acetic acid (EDTA) cross-linked chitosan and N,N-methylenebis(acrylamide) (MBA) cross-linked polyacrylamide based double network hydrogel was successfully synthesized via a two-step method and then employed for heavy metal ion adsorption. Various adsorption conditions, such as pH, ionic strength, adsorbent dosage, and contact time were investigated. CTS/PAM gel have a theoretical maximum Cd(II), Cu(II), and Pb(II) sorption capacities of 86.00, 99.44, and 138.41 mg/g, respectively, at experimental conditions. The adsorption process of CTS/PAM gel on the heavy metal ion was identified to be endothermic and follows an ion-exchange reaction. The application of this gel adsorbent was demonstrated using practical industrial effluent. We found that it could effectively treat practical wastewater with all kinds of heavy metals. At an adsorbent dosage of 8 g/L, the total metal ions concentration declined from 448.5 to 5.0 mg/L. Simultaneously, the CTS/PAM gel exhibited remarkable mechanical strength and good recyclability. This study shows that CTS/PAM gel offers great potential for practical application in the removal of heavy metal ions from contaminated aquatic systems.
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS
·
2016
·
IF 3.975
Yukun Wu,Jing Wu,Jing Cao,Yajie Zhang,Zhe Xu,Xiuyi Qin,Wei Wang,Zhi Yuan
Chitosan is one of the most important and commonly used natural polysaccharides in drug delivery for its biocompatible and biodegradable properties. However, poor blood circulation of the chitosan nanoparticles due to their cationic nature is one of the major bottlenecks of chitosan-based drug delivery systems. To address this problem, a versatile platform based on poly(acrylic acid) (PAA) coated ionically cross-linked chitosan/tripolyphosphate nanoparticles (CTS/TPP-PAA NPs), is reported. The zeta potentials of CTS/TPP and CTS/TPP-PAA NPs are approximately 33 mV and −25 mV, respectively. CTS/TPP NPs quickly aggregate in PBS (phosphate buffered saline) and DMEM (Dulbecco’s modified Eagle’s medium). Conversely, CTS/TPP-PAA NPs exhibit excellent colloidal stability in plasma solution for more than 24 h. The PAA coating also endows CTS/TPP-PAA NPs with decreased protein adsorption capacity and improved buffering capacity. More importantly, the residual carboxyl and amino groups on CTS/TPP-PAA NPs provide abundant reactive sites for further functional modifications. Therefore, the CTS/TPP-PAA NPs reported here may be useful as an alternative drug delivery system.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
IONICS
·
2017
·Vol. 24
·期 4
·1173-1180
·
IF 2.062
Yuan Yuan,Shen Chunhui,Chen Jiqin,Ren Xuechao
Novel alkaline anion-exchange membranes composed of quaternized chitosan and poly(diallyldimethylammonium chloride) were prepared by a combined thermal and chemical cross-linking technique. The hydroxide conductivity (σ), water uptake (WU), ion exchange capacity (IEC), thermal stability, mechanical property, alkaline stability of HTCC/PDDA-OH − membranes were measured to evaluate their applicability in alkaline fuel cells. FTIR, X-ray diffraction (XRD), and scanning electron microscopy (SEM) were also used to investigate the relation between the inner structure and performance of the blend membranes. The HTCC/PDDA-OH − membranes show a high OH − conductivity up to 37.9 mS cm −1 at 80 °C (1:0.5 by mass). By cross-linking modification, the membranes exhibit excellent thermal stability with onset degradation temperature above 200 °C and good alkaline resistance in 8M KOH solution at 80 °C, decreasing slightly for hydroxide conductivity during 350 h. Meanwhile, the membranes show outstanding mechanical properties, the maximum tensile strength can reach 25.31 MPa and elongation at break is 6.58%.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Nano Research
·
2017
·
IF 0.511
Wan Xin Jia,Dong Tao Lu,Shao Min Shuang,Jun Yang,Chuan Dong
Magnetic chitosan nanoparticles (Fe3O4-CS MNPs) were synthesized by an improved one-pot hydrothermal method and applied for azo dye amido black 10B adsorption. The Fe3O4-CS MNPs were characterized by SEM, TEM, DLS, XRD, FTIR, TGA and VSM. The adsorptive behavior of amido black 10B on Fe3O4-CS MNPs was investigated using the UV-vis specteophotometric technique and the affecting parameters including solution pH, contact time, amido black 10B concentration and Fe3O4-CS MNPs amount were examined. The adsorption process followed the pseudo-second-order kinetic model. The adsorption equilibrium data fitted well with the Freundlich isotherm model with the saturated adsorption capacity of 124.8 mg/g at pH=2.0. The desorption experiment could be carried out using NaOH with the recovery of 91.78%. After five cycles, adsorption efficiency still reached 83.24%. The results showed that Fe3O4-CS MNPs possessed a simple synthesis route and excellent reusability, which have potential application in the adsorption of azo dye in environmental effluents.
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Jianfang Jiang,Yongzheng Chen,Wei Wang,Baodong Cui,Nanwei Wan
In order to improve catalytic activity, increase recycling times, reduce use cost for enzyme, superparamagnetic carboxymethyl chitosan/sodium alginate nanosphere (SM/CMC/SA) has been synthesized via an improved hydrothermal method, molecular self-assembly technology, electrostatic interaction and amide linkage. Its mean diameter was 65 nm, zeta potential was −36.9 mV and BET was 53.8 m 2 /g. α-Amylase was selected as a simulation object to manufacture an immobilized enzyme (SM/CMC/CA/α-Amy), and its catalytic activity, release behavior, reusability and stability were researched. Immobilization increased 4.67 times to catalytic activity, slowed down release rate and improved reusable performance. SM/CMC/CA/α-Amy showed higher activity over a wider pH range, especially in strong acidic and alkaline environments. The thermal stability and storage stability were improved remarkably too. All these results indicated that SM/CMC/SA was an ideal carrier for immobilizing enzyme.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER TESTING
·
2017
·
IF 2.464
Xiaolan Zhang,Chuanlong Jia,Xiuying Qiao,Tianyi Liu,Kang Sun
Porous mSF/PGS and CS/PGS composite scaffolds were prepared by the combination of poly(glycerol sebacate) (PGS) with silk fibroin microfibers (mSF) and chitosan (CS) as modifiers through particulate leaching and freeze-drying techniques. Both mSF/PGS and CS/PGS scaffolds show highly interconnected and open porous structures, and the crosslink density and water absorption of PGS were obviously enhanced by the modifiers. Moreover, the silk fibroin microfiber and chitosan can slow down and control the degradation rate of PGS. The biocompatibility of these porous PGS based composite scaffolds for skin tissue engineering was evaluated by cell culture experiments, and the results indicate of the good attachment, proliferation and deep penetration of cells into these composite scaffolds.
✓ 已验证
产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2016
·
IF 7.476
Honghong Chang,Jia Lv,Haochun Zhang,Bing Zhang,Wenlong Wei,Yan Qiao
Chloramphenicol (CAP) is an antibiotic used for a variety of infections, however, it is banned for use in food-producing animals due to its hazards to humans blood . Herein, the highly sensitive photoresponsive colorimetric immunoassay was exploited based on AgI/TiO 2 heterojunction nanomaterials . Firstly, chitosan modified AgI/TiO 2 photocatalyst (CS-AgI/TiO 2 ) was synthesized by deposition-precipitation method, which was characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS) and Fourier transform infrared spectroscopy (FTIR). Then, by utilizing CS-AgI/TiO 2 labeled CAP antibody as tags, a novel competitive-type immunoassay was constructed for detection of CAP on the surface of CAP-BSA modified magnetic bead. The color development of 3,3 ′ ,5,5 ′ -tetramethylbenzidine (TMB) was obtained under visible light irradiation (λ≥420 nm) and the assay was carried out in pH 3.0 ABS buffer solution by UV–Vis spectrophotometry . Under optimal conditions, the absorbance values decreased with the increasing of CAP levels in sample, which exhibited linear in the range of 0.03–12.53 nM with a detection limit of 0.03 nM. Meanwhile, the selectivity , repeatability, and stability were acceptable. Excitedly, no significant difference was observed for detection of the spiked CAP in the real food samples with the referenced values.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 89
·85735-85744
·
IF 3.289
Bin Cai,Qin Zou,Yi Zuo,Limei Li,Boyuan Yang,Yubao Li
Composite microspheres based on nano-hydroxyapatite (n-HA)/chitosan (CS) with different weight ratios were fabricated by an emulsion method and using natural vanillin as a cross-linking agent. FT-IR, XRD, TGA, SEM and laser particle size analysis were used to characterize their physico-chemical properties. Live-dead cell staining and MTT assay were used to evaluate cell viability and cytocompatibility. The results showed that the rod-like n-HA crystals could be incorporated into the CS matrix in a relatively high level up to 29.57 wt%. The encapsulation efficiency of n-HA in the composite microspheres was between 29.50–73.93%. The composite microspheres with a diameter of 10.9–55.0 μm and good swelling properties should be easy to inject into irregular bone defects. The studies of in vitro biodegradation and cell culture using MG63 cells demonstrated that the vanillin-crosslinked n-HA/CS microspheres could be degraded in a sustained and controlled behavior while supporting cell growth, thus acting as worthy candidates for a multifunctional injectable matrix in bone tissue engineering.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2017
·
IF 3.671
Lijun You,Ci Huang,Feifei Lu,Ao Wang,Xiaocui Liu,Qiqing Zhang
A new porous magnetic chitosan-polyethylenimine (Fe 3 O 4 /CS-PEI) polymer composite was synthesized by crosslinking chitosan (CS) with polyethylenimine (PEI) in the present of FeCl 3 ·6H 2 O and FeCl 2 ·4H 2 O in alkaline condition and applied to remove congo red (CoR) from aqueous solutions. The Fe 3 O 4 /CS-PEI composite was characterized by SEM, XRD, TGA and FT-IR analysis. The polymer composite owned high positive charge, large surface area, multi-level pore distribution and magnetic responsiveness. The porous magnetic Fe 3 O 4 /CS-PEI composite showed ultrahigh capacity (1876 mg/g) for CoR removal. It removed over 99.3% of CoR (100 mg/L) when the dosage was over 1.4 g/L. A higher temperature was benefit to CoR removal. The Fe 3 O 4 /CS-PEI composite was effective for CoR removal in a wide pH range (3–13). Kinetics studies suggested that the adsorption mechanism of CoR followed the pseudo-second model and it was also affected by the boundary layer diffusion. The adsorption process followed the Redlich-Peterson isotherm equation. Thermodynamic studies also demonstrated that this adsorption process was spontaneous, favorable and endothermic. The activation energy (E a ) of the adsorption process was 34.08 kJ/mol, indicating that chemisorption existed in the process. The results demonstrated that the porous magnetic Fe 3 O 4 /CS-PEI polymer composite is a promising adsorbent for the efficient removal of dye pollutants from aqueous solution.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Hang Jia,Xue-Jian Liu,Xin Chen,Xin-Xin Guan,Xiu-Cheng Zheng,Pu Liu
Magnetic chitosan (CS-Fe 3 O 4 ) was synthesized via a co-precipitation method and used as supports to anchor palladium nanoparticles (Pd(0)/CS-Fe 3 O 4 ) by chemical reduction of PdCl 2 with NaBH 4 . The results showed that the nanosized palladium particles were highly dispersed onto CS-Fe 3 O 4 and the resulting Pd(0)/CS-Fe 3 O 4 catalysts exhibited high catalytic activity and good recyclability for the hydrolysis of ammonia borane (NH 3 BH 3 , AB). The turnover frequency (TOF) of the catalysts was as high as 15.0 m o l H 2 · m o l P d − 1 · m i n − 1 at 30 °C and the catalytic activity had not obvious decrease even after eight recycle experiments. The results of kinetic experiments showed that the activation energy of the reaction (E a ) is 35.94 kJ mol −1 . The orders of palladium and AB concentrations in the catalytic reaction were 0.70 and 0.62, respectively.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2017
·
IF 1.591
Shuang Zhang,Ting Lü,Dongming Qi,Hongting Zhao
Chitosan (CS)-based flocculants, denoted as CS-g-PAM and CS-g-PDBC, were successfully prepared via graft copolymerization of CS with acrylamide (AM) or dimethyl acryloyloxyethyl benzyl ammonium chloride (DBC). The grafting was confirmed by Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS). The flocculation performance of CS-g-PAM and CS-g-PDBC, as well as flocculants such as cationic polyacrylamide (CPAM), polyaluminum chloride (PAC), and CS, was evaluated and compared for treating emulsified oil wastewater. It was found that CS-g-PDBC exhibited excellent flocculation performance under both acidic and neutral conditions, while CS showed better flocculation ability under alkaline condition. The flocculation mechanism of CS and CS-g-PDBC was investigated via zeta potential measurements. Results showed that different flocculation mechanisms were involved at various pH levels. As regarding CS, the flocculation mechanism is mainly charge neutralization, patching, and sweep floc under acidic, neutral, and alkaline conditions, respectively, while for CS-g-PDBC, patching was the dominant mechanism under both acidic and neutral conditions.
✓ 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）