查找使用阿拉丁产品的科研文献

Preparation of supported chitosan adsorbent with high adsorption capacity for Titan Yellow removal

Qing-Xiang Shi,Yan Li,Li Wang,Jia Wang,Yun-Li Cao

The supported chitosan (CS) adsorbent (FZCS) was successfully prepared by load CS on the BSCS supporter in this work. The adsorbent was characterized by elemental analysis , FT-IR, XRD , TGA , SEM and N 2 adsorption-desorption techniques. The results showed the FZCS sorbent displayed the high removal rate (97.95%) for Titan Yellow (TY) anionic dye in aqueous solutions owing to its properties combining amino active functional amino group from the CS itself and higher specific surface area and mesoporous structure from the BSCS support. Isotherm data conform to the Langmuir isothermal model with a maximum adsorption capacity of 120.48 mg/g at 30 °C, suggesting monolayer adsorption of TY on the FZCS sorbent. The data were very well fitted to the pseudo-second-order kinetics. The adsorption capacity of FZCS could maintain about 70% after six cycles. The research indicated that FZCS would be a promising, eco-friendly and effective sorbent for anionic dye wastewater treatment in the near future.

Chitosan–polycaprolactone microspheres as carriers for delivering glial cell line-derived neurotrophic factor

Jiliang Wu,Chunyan Liao,Zheng Wang,Wenze Cheng,Nuo Zhou,Sheng Wang,Ying Wan

Chitosan–polycaprolactone (CH–PCL) copolymers with brush-like chain structures were synthesized. Some CH–PCLs with a PCL content less than 50   wt% were used to build glial cell line-derived neurotrophic factor (GDNF)-loaded microspheres via an emulsification method using genipin as a cross-linker. The resulting microspheres were spherical with a smooth surface and a diameter less than 40   μm; however, their loading efficiency could be higher than 80% if crosslinked properly. These microspheres had various swelling characteristics in lysozyme-containing PBS, which mainly depended on the PCL content, and they did not exhibit significant degradation up to 3   weeks. It is found that the PCL content in the CH–PCLs predominantly governed GDNF releases from some optimal microspheres and that the amount of cross-linker imposed limited impacts on the release behavior. Release kinetics revealed that GDNF release from microspheres was controlled by anomalous mechanisms involving Fickian diffusion and case-II transport. Some microspheres with an initial loading ratio of approximately 5-ng GDNF to 1.0-mg dry microsphere had sustained GDNF release upon addition of a simulant in vivo medium; an approximate linear rate of release was observed, which lasted over 4   weeks, was controllable and did not involve a significant burst release.

Preparation and characterization of mussel-inspired dual-crosslinked hydrogels based on hydroxypropyl chitosan

Zhao Xiaoliang,Lu Liyuan,Wan Wenpeng,Zhang Chuanhui,Liu Yuan,Luo Li,Zhu Tianke,Zhang Weijie

Marine mussels can adhere to various surfaces in a liquid environment by utilizing pedicle filaments, with the adhesive properties primarily attributed to the structure of catechol, the main component of the filament. To overcome the challenges associated with the complex preparation process, high cost, and potential biological rejection of naturally extracted or recombinantly expressed mussel proteins, researchers drew inspiration from mussels and utilized an oxidative crosslinking approach to prepare adhesive hydrogel materials. However, the hydrogels prepared using this method exhibited inferior mechanical properties and low viscosity. To address these limitations, in this study, a kind of mussel-inspired dual-crosslinked hydrogel was prepared by dual cross-linking with hydroxypropyl chitosan (HPCS) and hyaluronic acid (HA), based on catechol, an adhesion component in marine mussel pedicle filaments. Comparative analysis revealed that the mussel-inspired dual-crosslinked hydrogel exhibited significantly higher adhesion strength (up to 33.96 kPa) and improved mechanical properties (energy storage modulus ranging from 489 to 1032 Pa) compared to the mussel-inspired oxidatively cross-linked hydrogel. In addition, the mussel-inspired dual-crosslinked hydrogel demonstrated favorable swelling (up to 136.54 ± 0.22%), degradation, sustained-release, bacteriostatic and biocompatible properties. These findings suggest a promising potential for future applications in the field of biomedical materials.

Preparation of a novel antibacterial chitosan-poly(ethylene glycol) cryogel/silver nanoparticles composites

Xueqing Zou,Pengpeng Deng,Changjiang Zhou,Yulin Hou,Rongsheng Chen,Feng Liang,Liqiong Liao

Cryogel was synthesized through cryogelation of methacrylated carboxymethyl chitosan (mCMC) and poly(ethylene glycol) diacrylate (PEGDA) precursors by photopolymerization. Due to its excellent properties, such as fast swelling behavior, inter-connective porous structure, high water absorbing capacity, especially the presence of abundant carboxylmethyl groups on its backbone, the cryogel not only favored the absorption of silver ions but also was proved to be a good matrix for the incorporation of silver nanoparticles (AgNPs) by in situ chemical reduction. The structure, morphology, and swelling behavior of the cryogel and cryogel/AgNPs composite were characterized. And the results of inhibition zone test and antibacterial inhibition ratio indicated the cryogel/AgNPs composite exhibited prominent and durable antibacterial activity against Gram-negative E. coli and could be utilized as potential antibacterial materials.

Schiff base functionalized chitosan anion exchange membranes with 1,4-dichlorobutane as the crosslinker

Xu Han,XuYing Zheng,Shiyang Song,Jilin Wang,Lulu Wang

A series of composite membranes (CS-PY-DL x ) were synthesized by using schiff base functionalized chitosan (CS-PY) as the polymer matrix, 1,4-dichlorobutane (DL) as the crosslinker, the quaternization reagent is iodomethane . In this work, pyridine groups grafted on chitosan were converted into quaternary ammonium salt while forming cross-linked network structure. The FT-IR shows that the CS-PY-DL x membranes has been successfully prepared. The introduction of cross-linked structure enhances the alkali resistance, thermal stability and other properties of CS-PY-DL x membranes. When the cross-linked degree is 25%, the anion exchange membrane had the maximum tensile strength (24.45 MPa), and the anionic conductivity reaches 7.08 × 10 −3  S cm −1 at 70 °C. The alkali resistance test was researched under the condition of 3 mol L −1 KOH solution for 120 h at 80 °C, which showed that the OH − conductivity of CS-PY-DL 25 membranes retains approximately 79.7% of its initial conductivity, revealing the excellent alkali resistance. Methanol permeability was only 0.37–0.72% of the Nafion-117 membrane in 3M methanol at 60 °C, indicating an excellent resistance to alcohol.

Biosorptive removal of cobalt(II) from aqueous solutions using magnetic cyanoethyl chitosan beads

Qian Zhang,Shuting Zhuang,Jianlong Wang

Biosorption is a cleaner technology for the treatment of heavy metal-containing wastewater. In this study, a cleaner method was proposed for preparing a novel biosorbent, magnetic cyanoethyl chitosan beads, which was characterized by FT-IR, SEM-EDS, XRD, TGA, BET, and vibrating sample magnetometer, and applied for removing Co 2+ from aqueous solutions. The influencing factors, such as contact time (0−120 min), pH (5–8), and initial concentration of cobalt ions (10−600 mg L −1 ), were examined. The first-order, second-order, intraparticle diffusion, and Elovich models were used to simulate the kinetics of the cobalt adsorption process. The experimental data of isotherms were analyzed by the Langmuir, Freundlich, and Temkin models. Among them, the second-order model and Langmuir model were the best fitting. The adsorption capacity was calculated to be 17.92 mg g −1 according to the Langmuir model. From the analysis of the FT-IR spectra, it can be inferred that CN and NH 2 were mainly responsible for the adsorption of Co 2+ from aqueous solutions. The grafting of cyanoethyl groups on chitosan enhanced the sorption capacity towards Co 2+ , the magnetic cyanoethyl chitosan bead is economical and effective biosorbent for the treatment heavy metal-containing wastewater.

Removal of Cd(II) from aqueous solution using cross-linked chitosan–zeolite composite

Feng Zhang,Manman Wang,Limei Zhou,Xiaoyan Ma,Yafen Zhou

Cross-linked chitosan–zeolite composite was prepared and characterized by Fourier transform infrared spectroscopy and scanning electron microscope. Adsorption of Cd(II) by the cross-linked chitosan–zeolite composite as a function of solution pH, contact time, initial Cd(II) concentration, and temperature was investigated systematically by batch experiments. The obtained results showed that the removal of Cd(II) was pH dependent and the optimum adsorption was achieved at pH 7.0. The adsorption process could be described by pseudo-second-order kinetic model. Thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption. The batch adsorption data could be well elucidated by the Langmuir model. The maximum adsorption capacity of Cd(II) on the cross-linked chitosan–zeolite composite at 25°C determined from the Langmuir model was 102.15 mg/g. The adsorbent was successfully regenerated using EDTA, HNO3, and HCl solution as desorbent, respectively.

Preparation, Characterization, and Biochemical Activities of N-(2-Carboxyethyl)chitosan from Squid Pens

Jun Huang,Haihua Xie,Sheng Hu,Tian Xie,Jinyan Gong,Chengjun Jiang,Qing Ge,Yuanfeng Wu,Shiwang Liu,Yanli Cui,Jianwei Mao,Lehe Mei

Chitosan was prepared by alkaline N-deacetylation of β-chitin from squid pens, and N-carboxyethylated derivatives (N-CECS) with different degrees of substitution (DS) were synthesized. The carboxyethylation of the polysaccharide was identified by Fourier transform infrared, 1H and 13C nuclear magnetic resonance (NMR), and X-ray diffraction analyses. The DS of the derivatives was calculated by 1H NMR and elemental analysis. All three N-CECS samples showed good water solubility at pH > 6.5. The antioxidant properties and bile acid binding capacity of the derivatives were studied in vitro. The highest bile acid binding capacity of all N-CECS reached 36.9 mg/g, which was 2.6-fold higher than that of chitosan. N-CECS showed a stronger scavenging effect on 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical ability, and EC50 values were below 2 mg/mL. The scavenging ability of N-CECS against superoxide radicals correlated well with the DS and concentration of N-CECS. These results indicated that N-carboxyethylation is a possible approach to prepare chitosan derivatives with desirable in vitro biochemical properties.

Dissolution and regeneration behavior of chitosan in 3-methyl-1-(ethylacetyl)imidazolium chloride

Xu Bin,Li Qiaoping,Zhuang Linghua,Wang Qiang,Li Chao,Wang Guowei,Xie Fengwei,Halley Peter J.

3-methyl-1-(ethylacetyl)imidazolium chloride ([EtMIM]Cl), was synthesized for chitosan dissolution, and the dissolution and regeneration behaviors of chitosan in [EtMIM]Cl were thoroughly investigated. The solubility of chitosan in [EtMIM]Cl was measured at temperatures ranging from 40 °C to 110 °C, based on which the thermodynamic parameters of chitosan in [EtMIM]Cl were calculated. The polarizability and hydrogen bond accepting ability was determined by solvatochromic UV/vis spectroscopy. The regenerated chitosan from [EtMIM]Cl by adding methanol was characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Density functional theory (DFT) computations were performed to study the interactions between [EtMIM]Cl and chitobiose. Five kinds of hydrogen bonds, C-H/O, O-H/O, O-H/Cl, C-H/Cl, N-H/Cl were found, suggesting strong interactions between [EtMIM]Cl and chitobiose. In particular, the oxygen atom and the active methylene group of carboxylic ester in [EtMIM] + , formed strong hydrogen bonding with chitobiose. The molecular simulation results indicated that both the Cl − anions and [EtMIM] + cation played important roles in the chitosan dissolution process, by the disruption of native hydrogen bonds of chitosan.

Neodymium Modified Chitosan/PMMA Integrated Thin-Core Fiber for Trace Fluoride Ion Detection

Yi Jiang,Hongliang Chen,Xiaozhan Yang,Wenlin Feng

Functionalization of polyethylene terephthalate fabrics using nitrogen plasma and silk fibroin/chitosan microspheres

Zhibin Zhang,Zeyu Zhao,Zhaozhu Zheng,Shuai Liu,Senxian Mao,Xunxun Li,Yushuang Chen,Qingshan Mao,Lu Wang,Fujun Wang,Xiaoqin Wang,Zhijuan Pan,Gang Li

We demonstrate low-temperature nitrogen plasma (LTNP) and silk fibroin/chitosan microspheres (SFCM) for surface modification and functional treatment of polyethylene terephthalate (PET) fabrics to improve their antibacterial and antistatic properties. First, PET warp-knitting fabrics were treated by LTNP equipment. Then, the LTNP-treated fabrics were treated by SFCM solution. The surface properties of the PET fabrics, such as morphology, chemical composition , secondary structure , moisture regain, antistatic property, and breathability were analyzed using scanning electron microscopy, photoelectron spectroscopy , X-ray photoelectron spectrometer, Fourier transform infrared spectrometer, electrostatic charge decay tester, and automatic air permeability tester. The antibacterial properties of the PET fabrics were measured against. The results showed that the PET fabrics surface was roughened and nitrogen-containing groups were generated after LTNP treatment. Compared to SFCM-treated PET fabrics, the antistatic and hygroscopic properties of the LTNP-SFCM-treated PET fabrics have been significantly improved. The results also revealed that the LTNP-SFCM-treated PET fabrics had excellent antibacterial effects against Staphylococcus aureus (95.2 ± 1.2%) and Escherichia coli (92.1 ± 2.7%), and after washing ten times, the LTNP-SFCM-treated PET fabrics still had a strong antibacterial effect (73.1 ± 1.6%). Our approach can find potential applications for the development of functional textiles with improved antistatic and antibacterial performance.

Preparation of cellulose/chitosan superoleophobic aerogel with cellular pores for oil/water separation

Shuo Zhang,Yanqiu Pan,Wei Wang,Runze Lin,Xuewu Liu

Nanofibrillated cellulose (NFC)/chitosan (CS) composite aerogel with underwater superoleophobicity was prepared by freeze-drying for oil/water separation. The soft-ice freezing technique was employed to construct cellular pores for improving the mechanical performance while enhancing mass transfer of freeze-drying. The dielectric-aided microwave heating was adopted to enhance heat transfer of freeze-drying. The results showed that the prepared NFC/CS aerogel exhibited an excellent mechanical property with a stress of 87.16 kPa at 80% strain, and underwater superoleophobicity with all oil contact angles above 150˚. The proposed drying method could save over 40% of drying time, achieving a simultaneous mass and heat transfer enhancement of freeze-drying. The prepared aerogel provided separation efficiencies of all above 99.96% and average permeate fluxes of 0.817 and 0.826 L·m −2 ·s −1 after 20 cycles for oil/water and oil/seawater separations. The research results are expected to provide an economical and sustainable solution for the industrial oily wastewater treatment .