壳聚糖膜的制备及其性能测试

以天然高分子材料壳聚糖为原料,采用流延法制备了壳聚糖膜。研究了N-乙酰化和交联壳聚糖膜的制备方法及性能特性等。通过FTIR、XRD和SEM方法表征结构,并测试了力学性能。试验结果表明交联和乙酰化可以增加壳聚糖膜的拉伸强度提高膜的性能。     

壳聚糖膜分离乙醇／水溶液的渗透汽化性能研究

以脱乙酰化度为77．5％的壳聚糖为原料，采用高温浓碱处理的方法得到脱酰化度为98．2％的壳聚糖，分别用这两种壳聚糖制膜，用于乙醇／水混合物的分离，结果表明在同样条件下，脱乙酰化度高的壳聚糖膜的分离性能优于脱乙酰化度低的壳聚糖膜。     

季铵化/磺化壳聚糖的制备及其抗生物被膜活性

合成了N-(2-羟丙基-3-甲基氯化铵)壳聚糖（HTCC）、N,N,N-三甲基壳聚糖（TMC）和N-(2-羟丙基磺酸钠)壳聚糖（HSCS）。采用红外光谱、核磁共振氢谱、元素分析对产物的结构进行表征，分别比较不同结构的壳聚糖季铵盐（HTCC和TMC）以及相似结构的壳聚糖季铵盐和壳聚糖磺酸盐（HTCC和HSCS）的抗菌活性和抗生物被膜活性。实验结果发现，将壳聚糖的氨基直接季铵化得到的壳聚糖季铵盐（TMC）的抑菌率和生物被膜清除率要优于接枝季铵化得到的壳聚糖季铵盐（HTCC），季铵化壳聚糖（HTCC）的抗菌活性和抗生物被膜活性要优于磺化壳聚糖（HSCS）。0.5mg/mL的TMC对E. coli和S. aureus的抑菌率分别为93.0%和100%。TMC在1/2MIC浓度时对E. coli和S. aureus的生物被膜形成抑制率分别为51.4%和41.5%。2.5mg/mL的TMC、HTCC和HSCS对E. coli的生物被膜去除率分别为49.1%、48.6%和21.2%，对S. aureus的生物被膜的去除率分别为85.1%、82.7%和81.8%。     

铂纳米簇/N-己基化壳聚糖杂化膜催化苯加氢反应研究

对壳聚糖进行了N-己基化改性,并在此基础上制备了铂纳米簇/N-己基化壳聚糖杂化膜,研究了该杂化膜催化剂在苯加氢反应中的催化性能。利用FT-IR、TEM、XRD和XPS等手段对杂化膜催化剂的结构进行了表征。TEM结果显示,铂纳米粒子平均直径约为5 nm,XPS结果表明,Pt与壳聚糖中的N和O之间存在一定程度的配位。用N-己基化壳聚糖负载铂纳米簇杂化膜催化苯液相加氢反应,部分加氢产物环己烯的选择性可达60.3%,而单独以Pt纳米簇作为催化剂无壳聚糖膜时,没有环己烯生成。结合催化剂表征结果和催化性能分析,杂化膜在反应体系中的溶胀过程以及Pt与N、O之间的配位作用等因素是控制苯加氢反应的主要原因。     

多孔N-乙酰化壳聚糖超滤膜的制备及表征

以相转化法制备了N-乙酰化壳聚糖超滤膜,探讨了不同的致孔剂和蒸发条件对膜孔结构的影响,并用扫描电镜对其表面形貌进行了分析,并对膜的机械性能和对染料溶液酸性红B的分离性能进行了考察。分析结果表明:以乙醇为致孔剂、红外蒸发干燥10min制备的多孔壳聚糖膜孔径均匀,孔隙率高;膜的机械性能好,膜在干、湿态下的最大抗张强度分别达到445.4Kg/m2和182.4Kg/m2;膜的分离性能好,渗透通量达到2.1ml/cm2.h,截留率达到96.3%。     

甲壳素衍生物的制备工艺

介绍了多种甲壳素衍生物的制备工艺和生产方法 ,包括壳聚糖、羧甲基甲壳素、羧甲基壳聚糖、乙酰化壳聚糖、羧丙 (乙 )基壳聚糖、微晶甲壳素及壳聚糖、盐酸氨基葡萄糖、甲壳素硫酸盐、溴化甲壳素、N-乙基壳聚糖、季铵化壳聚糖、壳聚糖接枝共聚产物等十多种。     

水溶性壳聚糖改性天然胶乳的性能研究

采用乙酰化反应制备的水溶性壳聚糖改性天然胶乳(NRL),并对其性能和结构进行研究.结果表明:当pH值小于11时,水溶性壳聚糖在水中能够获得最佳溶解度.水溶性壳聚糖改性NRL胶膜的表面平整,致密性和耐溶剂性能优于纯NRL胶膜.当水溶性壳聚糖用量为1.5份时,NRL胶膜的综合物理性能最佳.水溶性壳聚糖赋予了NRL胶膜良好的生物相容性,达到了改善过敏性的目的,在医疗卫生领域具有广阔的应用前景.     

N-乙酰化壳聚糖超滤膜的分离性能

采用DMAc、乙酸酐和乙酰氯为乙酰化试剂对壳聚糖超滤膜进行乙酰化改性，研究了乙酰化壳聚糖超滤膜对酸性红B的分离效率。结果表明，随着乙酰化试剂用量的提高，壳聚糖膜的截留率增大，而渗透通量则逐渐降低，其中加入乙酰氯后截留率提高程度最大，截留率可达99%以上，而渗透通量的降低程度最小。     

甲壳素衍生物的制备工艺

介绍了多种甲壳素衍生物的制备工艺和生产方法,包括壳聚糖、羧甲基甲壳素、羧甲基壳聚糖、乙酰化壳聚糖、羧丙（乙）基壳聚糖、微晶甲壳素及壳聚塘、盐酸氨基葡萄糖、甲壳素硫酸盐、溴化甲壳素、N-乙基壳聚糖、季铵化壳聚糖、壳聚糖接枝共聚产物等十多种。     

N-乙酰化制备水溶性壳聚糖研究

以高脱乙酰度壳聚糖为原料,在不使用吡啶的无水乙醇均相体系中用乙酸酐通过N-乙酰化制备了水溶性壳聚糖,采用酸碱滴定、XRD、IR对壳聚糖原料和所制得水溶性壳聚糖的脱乙酰度、结晶状态、红外光谱分别进行了测试分析,并探讨了水溶性壳聚糖的结构与水溶性机理。     

多孔壳聚糖膜的制备表征及其吸附性能研究

以琼胶固体颗粒为致孔剂,通过热致相转移法制备了的多孔壳聚糖膜,并通过FT-IR和SEM对其进行了表征,也考察了其对有机染料二甲苯蓝FF的吸附性能。结果表明,以琼胶作为制孔剂可以制备出性能良好的多孔壳聚糖膜,在吸附有机染料方面,多孔壳聚糖膜PCS-2对二甲苯蓝FF的吸附量是壳聚糖膜的1.3倍。另外,作为对比,本文也制备和表征了琼胶-壳聚糖共混薄膜。     

壳聚糖/壳聚糖季铵盐交联共混阴离子交换膜的制备与性能研究

制备了一种新型阴离子交换膜——壳聚糖/壳聚糖季铵盐交联共混膜,并用FTIR对共混膜进行了初步表征;分析研究了不同交联度及配比对离子交换膜相关性能的影响;并运用测试膜电位的方法估算了离子的迁移数和选择透过度。研究表明,膜呈现较好的电化学性能,而膜的力学性能较差、含水量高、选择透过度稍低。HACC含量为25%,交联度为0.2%的共混膜干强与湿强分别为53.10 MPa和8.40 MPa,含水量66.4%,IEC为1.97 mmol/g,面电阻2.67Ω.cm2,离子迁移数为0.91,选择透过度为81.6%。     

The Study of Ethanol/Water Vapors Permeation through Sulfuric Acid Cross-Linked Chitosan Magnetic Membranes

Sulfuric acid cross-linked chitosan membranes filled with a different amount of magnetite, were prepared. The permeation behavior of ethanol and water vapors in vapor permeation experiments were studied. Permeation rates were measured. Mass transport coefficients were evaluated. The study has been carried out to determine the influence of magnetic powder dispersed inside of the chitosan membrane on ethanol-water separation. The diffusion, fluxes, and permeation coefficients increased with greater amount of magnetite content. The separation factor increased with increasing flux and the best results were achieved for the membrane containing 15% w/w magnetite. The research allows optimizing the preparation procedure of chitosan magnetic membranes cross-linked by sulfuric acid with the best permeation properties.     

Composite membranes of chitosan and titania‐coated carbon nanotubes as promising materials for new proton‐exchange membranes

Titania‐coated carbon nanotubes (TCNTs) were obtained by a simple sol–gel method. Then chitosan/TCNT (CS/TCNT) composite membranes were prepared by stirring chitosan/acetic acid and a TCNT/ethanol suspension. The morphology, thermal and oxidative stabilities, water uptake and proton conductivity, and mechanical properties of CS/TCNT composite membranes were investigated. The CNTs coated with an insulated and hydrophilic titania layer eliminated the risk of electronic short‐circuiting. Moreover, the titania layer enhanced the interaction between TCNTs and chitosan to ensure the homogenous dispersion of TCNTs in the chitosan matrix. The water uptake of CS/TCNT composite membranes was reduced owing to the decrease of the effective number of the ? NH₂ functional groups of chitosan. However, the CS/TCNT composite membranes exhibited better performance than a pure CS membrane in thermal and oxidative stability, proton conductivity, and mechanical properties. These results suggest that CS/TCNT composite membranes are promising materials for new proton‐exchange membranes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43365.     

Synthesis of Antibacterial Hybrid Hydroxyapatite/Collagen/Polysaccharide Bioactive Membranes and Their Effect on Osteoblast Culture

Inspired by the composition and confined environment provided by collagen fibrils during bone formation, this study aimed to compare two different strategies to synthesize bioactive hybrid membranes and to assess the role the organic matrix plays as physical confinement during mineral phase deposition. The hybrid membranes were prepared by (1) incorporating calcium phosphate in a biopolymeric membrane for in situ hydroxyapatite (HAp) precipitation in the interstices of the biopolymeric membrane as a confined environment (Methodology 1) or (2) adding synthetic HAp nanoparticles (SHAp) to the freshly prepared biopolymeric membrane (Methodology 2). The biopolymeric membranes were based on hydrolyzed collagen (HC) and chitosan (Cht) or κ-carrageenan (κ-carr). The hybrid membranes presented homogeneous and continuous dispersion of the mineral particles embedded in the biopolymeric membrane interstices and enhanced mechanical properties. The importance of the confined spaces in biomineralization was confirmed by controlled biomimetic HAp precipitation via Methodology 1. HAp precipitation after immersion in simulated body fluid attested that the hybrid membranes were bioactive. Hybrid membranes containing Cht were not toxic to the osteoblasts. Hybrid membranes added with silver nanoparticles (AgNPs) displayed antibacterial action against different clinically important pathogenic microorganisms. Overall, these results open simple and promising pathways to develop a new generation of bioactive hybrid membranes with controllable degradation rates and antimicrobial properties.     

Diffusional properties of chitosan hydrogel membranes

Chitosan membranes were prepared by a solvent evaporation technique, followed by crosslinking with glutaraldehyde and coating with BSA. The effects of crosslinking and BSA coating on the pore structure of such prepared hydrogel chitosan membranes were determined. The diffusion rates of 12 non‐electrolytes ranging in molecular radius between 2.5 and 14 Å through the membranes were measured, and the results were interpreted in terms of the capillary pore model and free volume model of solute diffusional transport through hydrogel membranes. Glutaraldehyde crosslinking was found to reduce the membrane water content and consequently the membrane pore size and surface porosity, whereas further BSA coating brought about the opposite effect. The latter effect lessened with an increase in glutaraldehyde pretreatment of the membranes. The optimal chitosan membrane preparation, compromising between the solute flux and membrane stability and durability was obtained when the membranes were crosslinked with glutaraldehyde at concentrations between 0.01 and 0.1% (w/w). The knowledge of transport properties and of physical strength of the membranes is of importance for the development of chitosan‐based controlled release systems. © 2001 Society of Chemical Industry     

纳米纤维素晶须-壳聚糖/聚乙烯醇复合膜性能与细胞相容性

以椰壳纤维为原料,制备了纳米纤维素晶须,用硅烷偶联剂对纳米纤维素晶须进行改性,将改性后纳米纤维素晶须与壳聚糖、聚乙烯醇共混,采用溶液浇铸法制备了改性纳米纤维素晶须-壳聚糖/聚乙烯醇复合膜。采用FTIR、DSC、TG、XRD和SEM对改性纳米纤维素晶须-壳聚糖/聚乙烯醇复合膜的结构、热性能、结晶行为和形貌进行表征与分析,对复合膜的力学性能和水接触角进行测试,将成纤维细胞L929接种到复合膜上,对其进行细胞相容性实验。结果表明,添加改性纤维素晶须,能够使壳聚糖/聚乙烯醇复合膜的热性能、结晶行为和力学性能提高,成纤维细胞在复合膜上具有较好的黏附和生长,制备的纳米纤维素晶须-壳聚糖/聚乙烯醇复合膜具有良好的综合性能和细胞相容性。     

Pervaporation of water/alcohol mixtures through chitosan/cellulose acetate composite hollow‐fiber membranes

For the purpose of separating aqueous alcohol by the use of pervaporation technique, a composite membrane of chitosan (CT) dip‐coated cellulose acetate (CA) hollow‐fiber membranes, CT‐d‐CA, was investigated. The effects of air‐gap distance in the spinning of CA hollow‐fiber membranes, chitosan concentration, and sorts of aqueous alcohol solutions on the pervaporation performances were studied. Compared with unmodified CA hollow‐fiber membrane, the CT‐d‐CA composite hollow‐fiber membrane effectively increases the permselectivity of water. The thickness of coating layer increases with an increase in chitosan concentration. As the concentration of chitosan solution increased, the permeation rate decreased and the concentration of water in the permeate increased. In addition, the effects of feed composition and feed solution temperature on the pervaporation performances were also investigated. The permeation rate and water content in permeate at 25°C for a 90 wt % aqueous isopropanol solution through the CT‐d‐CA composite hollow‐fiber membrane with a 5‐cm air‐gap distance spun, 2 wt % chitosan dip‐coated system were 169.5 g/m² h and 98.9 wt %, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1562–1568, 2004     

Effect of Solvent on Physico-Chemical Properties and Antibacterial Activity of Chitosan Membranes

Chitosan is widely used in various applications such as pharmaceutical, medical, wastewater treatment (WWTR), and antibacterial. Modifying chitosan's properties is still attractive in scientific and industrial research. The acid solvation effect on the antibacterial activity (ABA) and physico-chemical properties of chitosan membranes synthesized via the solution casting-solvent evaporation technique was investigated. Various acids such as acetic, ascorbic, citric, glycolic, maleic, oxalic, and tartaric acid were used as chitosan solvents and membrane properties were characterized by Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) in order to study chemical interaction between the acid solvent and the shift of carbonyl and amine groups. Thermogravimetric analysis (TGA), static swelling, membrane thickness, and tensile strength experiments also characterized the membranes’ physical, chemical, and thermal properties. Further, the effect of acid solvation on the ABA of chitosan membranes for WWTR was interrogated with Escherichia coli and acetic acid solvated chitosan membrane exhibited highest ABA (99%).