3种壳聚糖膜的制备及性能比较

以壳聚糖为原料,采用流延法制备了壳聚糖膜、N-乙酰化壳聚糖膜。采用FTIR、XRD和SEN对3种膜的结构和形貌进行了表征,并比较了3种膜的性能。结果表明,N-乙酰化壳聚糖膜的力学性能和耐酸性能好于其它两种膜。     

交联壳聚糖/聚乙烯醇共混膜的制备及表征

用乙酸和水为溶剂,通过相转化法制备了三种不同比例混合的壳聚糖(CS)和聚乙烯醇(PVA)共混膜,然后在碱性条件下用环氧氯丙烷对共混膜进行了交联。采用FTIR、DMA、TG、XRD和SEM对所制备的膜进行了表征,测试了交联前后膜的溶胀性能和机械性能。测试结果表明:壳聚糖与聚乙烯醇两组分相容性良好,共混膜的机械性能、热稳定性和结晶度均介于两种纯组分之间;聚乙烯醇的加入提高了壳聚糖膜的机械性能;环氧氯丙烷的交联使共混膜的溶胀性能得到明显改善,而热稳定性和机械性能略有下降。     

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。     

壳聚糖制膜研究

甲壳素是广泛存在于自然界的一种天然高分子材料。本文制备了甲壳素的一种重要衍生物壳聚糖，并与戊二醛交联制备了壳聚糖交联膜。用红外光谱和扫描电镜探讨了壳聚糖交联前后的差异。     

小孔径壳聚糖/聚丙烯腈复合超滤膜的研制

以聚乙二醇二缩水甘油醚(PEGDGE)为交联剂,将壳聚糖(CTS)交联到聚丙烯腈(PAN)基膜的表面,制备了壳聚糖/聚丙烯腈复合超滤膜。探讨了交联剂浓度、交联温度及交联时间对CTS/PAN复合超滤膜性能的影响,确定了最佳制膜条件。结果表明,在最佳条件下所制备的CTS/PAN复合超滤膜对聚乙二醇4000的截留率达94%以上,膜面粗糙度降低,亲水性得到明显提高,增强了膜片的抗污染性能。     

壳聚糖/聚砜复合纳滤膜的制备

纳滤膜在水处理过程中的应用越来越受到关注。本试验通过在不同条件下制备壳聚糖/聚砜复合纳滤膜,研究了膜厚度,膜干燥温度,凝固浴浓度、温度和凝固时间,交联剂浓度、温度和交联时间,热处理温度和时间等因素对膜性能的影响。试验表明制备工艺条件对膜性能影响很大,主要体现在温度、浓度和反应时间方面。最后通过试验,获得了壳聚糖/聚砜复合纳滤膜的最佳制备条件。     

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%。     

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.     

羧甲基壳聚糖-聚乙烯醇渗透汽化膜分离乙醇-水的性能

本文制备了羧甲基壳聚糖-聚乙烯醇渗透汽化膜,研究了羧甲基壳聚糖和聚乙烯醇配比、戊二醛交联时间以及操作温度和乙醇浓度等因素对膜分离乙醇-水性能的影响。实验结果表明,当乙醇含量较低（10（wt）%）时,该膜优先透醇,羧甲基壳聚糖与聚乙烯醇的比例1∶1时,膜的分离因子达到最大16.45（wt）%的乙醇溶液）;随着戊二醛交联时间的增加,膜的渗透通量减小而分离因子增大;操作温度升高,膜的渗透通量增大,而分离因子降低。     

光交联明胶-壳聚糖共混膜制备及性能研究

本实验用以聚乙烯醇-苯乙烯基吡啶盐的缩合物(PVA-SbQ)为光敏剂,运用紫外光辐照法以制备交联明胶-壳聚糖共混膜。用傅立叶红外、X-射线衍射方法对膜的结构进行表征,并对膜的力学性能、吸湿率、透光率性能进行研究。研究表明:PVA-SbQ分子与明胶、壳聚糖分子间存在氢键作用,光交联后,共混膜形成网状结构,有效地改善了共混膜的力学性能、吸湿性和紫外屏蔽性能等。     

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。     

丝素/羧甲基壳聚糖共混膜的结构性能探讨

将含有甘油和戊二醛的丝素与羧甲基壳聚糖按一定比例混合,制得丝素/羧甲基壳聚糖共混膜,对共混膜的结构与性能进行了探讨。结果表明:随着羧甲基壳聚糖含量的增加,共混膜的透气率增大,加入交联剂戊二醛有效地改善了共混膜的力学性能,但其透气率有所降低;当丝素与羧甲基壳聚糖的质量比为4/1时,共混膜的断裂强度最大,力学性能较好,共混膜相容性较好,其断面光滑、致密。制备丝素/羧甲基壳聚糖共混膜的较佳条件为:丝素中的甘油质量分数为15%,戊二醛质量分数为0.075%,丝素与羧甲基壳聚糖质量比为4/1。     

Characterization and performance evaluations of sodium zeolite‐Y filled chitosan polymeric membrane: Effect of sodium zeolite‐Y concentration

Sodium zeolite‐Y (NaY zeolite) filled chitosan polymeric membranes were developed and characterized. The impact of adding different concentrations of NaY zeolite into the homogeneous chitosan membrane was investigated. The surface morphology, mechanical–physical properties, sorption, and pervaporation performance for the dehydration of isopropanol–water mixture separation by the pervaporation process were studied and evaluated. A homogeneous chitosan membrane showed preferential water sorption and permeation compared to isopropanol. The optimum concentration of NaY zeolite added to the homogeneous chitosan membrane was 0.4 wt %, which showed that the dispersion of the NaY zeolite was the most homogeneous and finely covered by the chitosan polymer in the zeolite–chitosan polymer interface. The tensile strength and percent strain at maximum of this membrane were 59.347 MPa and 27.5%, respectively. The sorption experiments showed that the degree of swelling was 6.54% with 1.01 wt % isopropanol sorbed in these membranes. The pervaporation separation tests demonstrated that the NaY zeolite filled chitosan membrane was capable for isopropanol–water mixture separation and improved the pervaporation separation index from 272 (homogeneous chitosan membrane) to 2687. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1740–1751, 2006     

聚电解质静电沉积改性制备高性能反渗透膜

利用次氯酸钠溶液对商品反渗透膜表面进行氯化处理,然后将聚阳离子电解质壳聚糖通过静电吸附作用沉积在RO膜的表面,系统地研究了氯化过程的pH、氯化时间、次氯酸钠浓度、壳聚糖浓度及其沉积时间对膜性能的影响,以制备出高通量、高截留率的RO膜。在压力1.55 MPa、原料液温度（298±1）K的条件下,测定RO膜处理2000 μg·g^-1氯化钠溶液的水通量和截留率。结果表明,当pH=9、氯化时间为30 min、次氯酸钠浓度为1000 mg·L^-1时,水通量较原膜提高了约19.89%,截留率略有提高;当壳聚糖浓度为0.1%（质量分数）、沉积时间为30 min时,改性膜的接触角降低到34.88°,亲水性提高,水通量较氯化后的RO膜几乎保持不变,为60.55 L·m^-2·h^-1,截留率达到了99.56%。经过氯化和沉积改性后的RO膜水通量和截留率均得到了提高。     

Effect of membrane preparation conditions on solute permeability in chitosan membrane

Chitosan membrane was prepared in various conditions and diffusive permeabilities of theophylline and vitamin B₁₂ were investigated. The membrane preparation procedure consists of dissolving chitosan in acid solution, cast on the glass plate, drying the dope solution, and immersion of the plate in the gelating agent. Effects of the kinds of acids to dissolve chitosan, chitosan concentration, drying time of the dope solution, and the kinds of the gelating agent on the membrane structure and performance were studied in detail. With increasing the chitosan concentration, the solute permeability decreased, while the selectivity of theophylline to vitamin B₁₂ increased. The membrane changed from the wholly porous structure to the asymmetric structure by the increase of the chitosan concentration. Furthermore, the use of ethanol as the gelating agent brought about the wholly porous structure with the high permeability and the low selectivity. The asymmetric structure and the wholly dense structure were obtained in the cases of the gelating agents, such as aqueous NaOH solution and dimethyl sulfoxide (DMSO), respectively. Thus, the membrane structure can be controlled by the kinds of gelating agent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2715–2725, 1999     

凝固浴处理对聚氨基葡糖超滤膜分离性能的影响

采用凝固浴凝胶工艺处理聚氨基葡糖超滤膜，实验结果表明，经凝固浴处理后，聚氨基葡糖超滤膜对酸性红B溶液的截留率提高了83.7%；凝固浴的温度、凝固剂的浓度、凝固时间等参数对聚氨基葡糖超滤膜的截留率、渗透通量和孔结构均有一定的影响，选择适当的处理条件可提高膜的分离效率.     

Separation of alcohol–water mixture by pervaporation through a novel natural polymer blend membrane–chitosan/silk fibroin blend membrane

A novel natural polymer blend membrane, namely chitosan/silk fibroin blend membrane, was prepared. The selective solubility and the pervaporation properties of alcohol–water mixture were studied. The results showed that the membrane was water selective and the separation factor of ethanol–water mixture could be improved compared to pure chitosan membrane, when silk fibroin content in blend membrane was no more than 40 wt %. The blend membrane exhibited a best performance, (i.e., the water in permeate was large than 99 wt % when silk content was 20 wt % and the crosslinking agent–glutaraldehyde content was 0.5 mol %). The mechanism of improvement on pervaporation properties was explained by reducing the free volume and freeing hydrophilic groups of chitosan because of the strong intermolecular hydrogen bond forming between chitosan and silk fibroin in blend membrane. In addition, the influence of operation temperature and feed concentration as well as the pervaporation properties of isopropanol–water mixture were also studied. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 975–980, 1999     

改性壳聚糖加碘膜的制备与表征

壳聚糖(CTS)和水杨醛、环氧氯丙烷交联制备壳聚糖衍生物(RS-CTS-E),并制备相应衍生物的凝胶膜,将凝胶膜浸没在一定浓度碘乙醇溶液中,制备改性壳聚糖加碘膜(RS-CTS-E-I2),并对其进行了IR、SEM等表征。碘含量分析表明:改性壳聚糖凝胶膜对单质碘吸附量随碘乙醇溶液浓度增加而增大。碘吸附动力学结果表明其平衡吸附时间为6 h。抑菌性测试结果表明,w(I2)=19.05%时RS-CTS-E-I2膜对金黄色葡萄球菌抑菌环和大肠杆菌抑菌环的抑菌环直径分别为(31±1)mm和(30±1)mm,均为高度敏感。     

Pervaporation separation of water/ethanol mixtures through polysaccharide membranes. II. The permselectivity of chitosan membrane

The separation of water/alcohol mixtures through chitosan membrane was investigated. The degree of the deacetylation of chitosan did not affect the selectivity of the membrane in the separation of the water/ethanol mixture. The selectivity of the chitosan membrane was affected by the specific salts such as CoSO₄, ZnSO₄, and MnSO₄ and it increased when the salts were present in the feed mixture or the membrane was pretreated with the salt solution. This behavior would be explained by the contraction of the “holes” produced by the thermal motion of polymer chains and this contraction would be correlated with the conformation change of chitosan molecule due to the formation of complexes with metal ions.