聚电解质复合物

本文介绍了聚电解质复合物的研究及发展状况，包括聚电解质复合物的形成、结构以及影响形成聚电解质复合物的各种因素，还介绍了近年来以聚电解质复合物为材料 质的渗透汽化膜的应用和在生物医药方面的研究成果。     

高分子复合物纤维的研究进展

功能化和智能化是纤维发展的趋势.单一组分纤维难以满足日益发展的需求,而多组分纤维能够集中不同组分的特点,实现性能的集成与优化.通过非共价相互作用,高分子聚集而形成多组分均相体系,称为高分子复合物.利用高分子复合物的形成过程使纤维成型;或者直接利用高分子复合物进行纺丝而得到的纤维称为高分子复合物纤维.高分子复合物纤维,各组分可以达到分子层面上的相容性,给我们提供了一个功能纤维和智能纤维设计开发的平台.本文详细阐述了各类高分子复合物纤维的研究现状,并展望高分子复合物纤维的未来发展.     

聚电解质复合物在药物控释中的应用

近年来聚电解质复合物在药物控释领域受到重视。对聚电解质复合物在响应型药物控释、细胞免疫隔离移植、多肽蛋白质药物的缓释及其基因治疗等领域的应用进行了综述。     

脱乙酰壳多糖——羧甲基纤维素聚电解质复合物的合成和药物控 …

本文研究合成条件对脱乙酰壳多糖－羧甲基纤维素聚电解质复合物的组成。结构及药物控制释放性能的影响。结果表明,反应介质的ｐＨ值对生成的脱乙酰壳多糖－羧甲基纤维素聚电解质复合物的组成和结构的影响最大,在ｐＨ值５．５合成的脱乙酰壳多糖－羧甲基纤维素聚电解质复合物具有较好的药物控释性能。     

藻朊酸钠/壳聚糖聚电解质复合物膜 Ⅰ.对水/有机液体系的渗透汽化特性

制备了藻朊酸钠／壳聚糖聚电解质复合物复合膜，研究了进料液浓度、温度等对水／乙醇体系渗透汽化特性的影响；发现膜的不同表面接触进料液时膜的分离性能不同。同时，对其它水／有机液体系，该膜也具有优异的分离性能。     

壳聚糖基聚电解质复合物在生物医学领域的应用

近年来,国内外对壳聚糖在生物医学领域的应用研究十分活跃。壳聚糖在低pH时带正电荷,在溶液中可与带负电荷的聚离子形成聚电解质复合物。壳聚糖基聚电解质复合物除了具有壳聚糖的生物相容性,还表现出良好的物理化学性质,在药物控制释放体系、蛋白质分离、生物酶以及细胞固定化等领域具有广泛应用。本文重点介绍壳聚糖与几种天然的或合成的聚阴离子形成的聚电解质复合物及其在生物医学领域的应用。     

高分子复合物固定化纤维素酶的研究

<正> 固定化酶是将水溶性的酶用物理或化学方法处理,使之变成不溶于水的仍具有酶活性的酶衍生物。在催化反应中,它以固相状态作用于底物。固定化酶不但仍然具有酶的高度专一性及温和条件下高效率催化的特点,还可反复使用。这样,酶经固定后,稳定性有较大增加,可贮藏较长时间。 用高分子复合物固定生物酶是固定化酶的一个新的尝试。两种不同的高分子链通过氢键力、库伦力、范德华力、疏水键力等所谓次价键而聚集成高分子复合物。高分子复合物具有一些特殊功能,如优良的质量传递性能、对水、电解质的灵敏介电特性,对氧和水     

可生物降解肝素钠/两性壳聚糖复合物用于蛋白药物pH响应释放研究

制备了一类可生物降解肝素钠两性壳聚糖复合物(HPACS),并探索将其用于蛋白药物pH响应释放.两性壳聚糖由壳聚糖与丙烯酸加成反应得到,丙烯酸取代度可通过丙烯酸壳聚糖投料比调控;用胶体与pH浊度滴定研究了肝素钠与两性壳聚糖的复合作用,发现两组分在一定pH范围内能通过静电相互作用形成复合物,复合转变临界pH(pHΦ)与两性壳聚糖中丙烯酸取代度有关,取代度越低,pHΦ值越高.以牛血清白蛋白(BSA)为模型,测定了其在复合物中包埋及不同pH介质中的释药行为.结果表明,BSA可以在非常温和条件下有效包埋于复合物中,包埋率接近100%;BSA从复合物中释放具有很高的pH响应性,释放转变在很窄的pH范围内(<0.4pH单位)完成,释放转变临界pH(pH′Φ)可由两性壳聚糖中丙烯酸取代度调控.复合物形成和蛋白质释放在对pH依赖性上存在很好的相关性.同时还发现,在中性介质中(pH7.4),复合物对BSA具有很好的缓释作用,BSA持续释放时间可达15天左右.     

酚氧树脂/聚(4-乙烯基吡啶)高分子复合物的制备及表征

采用元素分析、DSC、FTIR、紫外光谱及XPS等手段对酚氧树脂和聚(4-乙烯基吡啶)在氯仿中溶液共混形成的高分子复合物的组成及结构进行了研究,并与相应的共混物作了比较。结果表明,所得的各复合物的组成相同,其值与组分分子中的链节等摩尔比一致;而共混物也为相容体系,其组成与两高分子组分的投料比对应。基于实验结果,揭示了复合物的形成过程。     

Interpolymer complexation in hydrolysed poly(styrene-co-maleic anhydride)/poly(styrene-co-4-vinylpyridine)

Complexation between hydrolysed poly(styrene-co-maleic anhydride) (HSMA) copolymers containing 28% and 50% maleic anhydride and a poly(styrene-co-4-vinylpyridine), St4VP32 copolymer with 32% of 4-vinylpyridine content has been investigated. Formation of interpolymer complexes from 1,4-dioxane solutions is observed, over the entire composition range and the stoichiometry of these complexes has been determined from elemental analysis.Quantitative FTIR study of the system HSMA50/StV4Py32 shows that the ideal complex composition leads to 2:1 unit mole ratio of interacting component. FTIR results are in good agreement with DSC and TGA ones, since this complex composition gives the maximum value of the glass transition temperature and the best thermic stability.For the systems investigated, the T_g versus composition curve do not follow any of the commonly accepted models proposed for polymer blends. A new model proposed by Cowie [Cowie JMG, Garay MT, Lath D, McEwen IJ. Br Poly J 1989;21:81] is used to fit the T_g data and found to reproduce the experimental results more closely.     

Interpolymer complexes of poly(acrylic acid) with poly(2-hydroxyethyl acrylate) in aqueous solutions

Complexes formed from poly(acrylic acid) and poly(2-hydroxyethyl acrylate) were studied in aqueous solutions by viscometric, turbidimetric, FTIR spectroscopic, and thermogravimetric analysis methods. The formation of interpolymer complexes stabilized by hydrogen bonds was observed. It was found that the compositions of these interpolymer complexes are strongly dependent on the concentration of polymers, the order of mixing the solutions, and the pH. It was demonstrated that the complexation ability of poly(2-hydroxyethyl acrylate) is relatively low compared to other known nonionic water-soluble polymers. However, it can be significantly increased via hydrophobic modification of the poly(acrylic acid) using cetyl pyridinium bromide.     

Interpolymer Complexes of Poly(N,N-Dimethylacrylamide/Poly(Styrene-co-Acrylic Acid): Thermal Stability and FTIR Analysis

Summary: This contribution will focus on the elaboration and characterizations of new materials with optimal properties as interpolymer complexes, upon mixing poly (styrene-co-acrylic acid containing 18, 27 and 32 mol % of acrylic acid (SAA-x) and poly (N,N-dimethylacrylamide) (PDMA), through the control of the densities, strength, self-association and accessibility of the interacting species. These elaborated interpolymer complexes, of different structures, investigated by DSC and TGA, exhibited a significant improved thermal stability. Their DSC analysis showed that all these materials showed one composition-dependence glass transition temperature Tg, indicating the formation of a single homogeneous phase. The different behaviors of Tg-initial composition observed with these systems were analyzed by the approaches of Kwei and Brostow et al., recently developed. The specific interactions that occurred within the elaborated materials were evidenced qualitatively by ATR/FTIR spectroscopy, from the appearance of new bands in the 1800–1550 cm⁻¹ region.     

Viscosity properties of sodium carboxymethylcellulose solutions

Through viscosity measurements, concentration and temperature dependences of viscosity of sodium carboxymethylcellulose (CMC) solution were recorded. Effects of glycerin, mechanical shearing and several electrolytes on the CMC solution were also determined. Results showed that the viscosity dependence on concentration obeyed the Huggins and Kramer equation, the dependence on temperature complied with the Arrhenius equation. CMC chain could synergize with glycerin, konjac glucomannan (KGM), and aluminum sulfate 18-hydrate. Sodium chloride, hydrochloric acid, and calcium dichloride reduced the viscosity of the CMC solution. By suggesting the ion-binding and hydrogen bond as the major form of the electrostatic interaction in the CMC solution, the synergistic and pseudoplastic phenomena as well as the maximum over stirring time were reasonably explained.     

Hollow capsules formed in a single stage via interfacial hydrogen-bonded complexation of methylcellulose with poly(acrylic acid) and tannic acid

Hollow capsules can be prepared in a single stage by the interfacial complexation of methylcellulose (MC) with poly(acrylic acid) (PAA) or tannic acid (TA) via hydrogen bonding in aqueous solutions. The formation of capsules is observed when viscous solution of methylcellulose is added drop-wise to diluted solutions of polyacids under acidic conditions. The optimal parameters such as polymer concentration and solution pH for the formation of these capsules were established in this work. It was found that tannic acid forms capsules in a broader range of concentrations and pHs compared to poly(acrylic acid). The TA/MC capsules exhibited better stability compared to PAA/MC in response to increase in pH: the dissolution of TA/MC capsules observed at pH > 9.5; whereas PAA/MC capsules dissolved at pH > 3.8. The interfacial complexation can be considered as a potential single stage alternative to the formation of capsules using multistage layer-by-layer deposition method.     

微球-三维支架复合体系控制释放生长因子的研究进展

将载生长因子的微球和组织工程三维支架复合得到的微球-三维支架复合体系,能够实现多种生长因子的依次释放和连续释放,满足新组织形成过程中不同阶段对不同量的各种生长因子的需求。在综述了微球和支架作为载体的载生长因子方法及优缺点的基础上,评述了微球-三维支架复合体系的三种制备方法,即自上而下法、复合溶结法和直接混和法,归纳和总结了国内外对微球-三维支架复合体系的研究现状和进展。并阐述了微球-三维支架复合体系的释放机理,指出了微球-三维支架复合体系在理想组织修复中的发展潜力和面临的挑战。     

取代基对1-甲基尿嘧啶与N-甲基乙酰胺氢键复合物中氢键强度的影响

使用密度泛函理论B3LYP方法和二阶微扰理论MP2方法对由1-甲基尿嘧啶与N-甲基乙酰胺所形成的氢键复合物中的氢键强度进行了理论研究, 探讨了不同取代基取代氢键受体分子1-甲基尿嘧啶中的氢原子对氢键强度的影响和氢键的协同性. 研究表明: 供电子取代基使N－H…O＝C氢键键长r(H…O)缩短, 氢键强度增强; 吸电子取代基使N－H…O＝C氢键键长r(H…O)伸长, 氢键强度减弱. 自然键轨道(NBO)分析表明: 供电子基团使参与形成氢键的氢原子的正电荷增加, 使氧原子的负电荷增加, 使质子供体和受体分子间的电荷转移量增多; 吸电子基团则相反. 供电子基团使N－H…O＝C氢键中氧原子的孤对电子轨道n(O)对N－H的反键轨道σ^*(N－H)的二阶相互作用稳定化能增强, 吸电子基团使这种二阶相互作用稳定化能减弱. 取代基对与其相近的N－H…O＝C氢键影响更大.     

The influence of metal ions on neighbouring hydrogen bonds

The influence of metal ions on hydrogen bonds formed by their ligands to other molecules is studied at the example of the water dimer and lithium ion by means of ab initio calculations using a 8s/4p + P Gaussian basis set. Potential curves for the dimer separation and proton transfer are reported, and the results are used to discuss the ion influence on structure, rotation and the first part of the autoprotolysis reaction of the dimer. Several properties of electrolyte solutions can be related to the principal effects predicted by our calculations.     

Interpolymer Complexes of Water‐Soluble Nonionic Polysaccharides with Polycarboxylic Acids and Their Applications

Literature data as well as our own experimental results devoted to the complexation of polycarboxylic acids with various water‐soluble polysaccharides (methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, starch, and dextran) by means of hydrogen bonding are systematized and analyzed. The specific peculiarities of interpolymer complexes based on polysaccharides‐polycarboxylic acids are demonstrated. The perspectives for the application of these interpolymer complexes are considered. It was shown that these materials possess good biocompatibility and adhesive properties. The promising directions for further study of interpolymer complexes between polycarboxylic acids and nonionic polysaccharides as well as existing gaps in the knowledge in this field are pointed out.

Formation of compact IPCs and hydrophilic interpolymer associates.