乙酸乙烯酯接枝改性海藻酸钙凝胶微球

为了降低海藻酸钙凝胶微球的溶胀度,以乙酸乙烯酯（VAc)对海藻酸钠进行自由基接枝共聚,进而制备具有较低溶胀度的聚乙酸乙烯酯改性海藻酸钙(Ca-SA-PVAc)凝胶微球。红外光谱表明,改性之后海藻酸钙的分子上生成新的化学键;热重分析表明,改性微球受热失水行为发生变化,热稳定性提高;扫描电镜表明,改性微球结构孔隙结构发达;接枝反应条件如反应温度、VAc的浓度、引发剂用量、海藻酸钠浓度、钙离子浓度及反应时间等对改性凝胶微球在生理盐水中的抗溶胀性具有不同程度的影响。通过改变反应条件以控制接枝反应参数,可以获得溶胀行为可控的改性海藻酸钙凝胶微球。     

基于微流控技术的水凝胶仿生纤维的制备及其性能调控

海藻酸钙水凝胶纤维在细胞培养、药物释放等生物医学领域具有广阔的应用前景,但传统模具法或静电纺丝法制备水凝胶的效率较低、性能较差。基于微流控技术制备了连续、均一、稳定的海藻酸钙水凝胶纤维,利用电子显微镜观察其形貌和结构,并在流控过程中探究了两相流速、溶液浓度及芯片尺寸等因素对水凝胶纤维性能的影响。结果表明,纤维的尺寸和力学性能都可以利用微流控技术在一定范围内进行灵活高效的调控。     

超薄壁结构海藻酸钙胶囊膜制备及其功能化研究新进展

海藻酸钙胶囊膜由于具有制备过程温和环保、材料生物相容性优良等优点,广泛应用于生物医药等领域。薄壁结构的胶囊膜可减小跨膜传质阻力,加速囊膜内外物质的交换,因而备受学术界和工业界的广泛关注。近年来,具有超薄壁结构的海藻酸钙胶囊膜的制备与改性成为一个研究热点。本文综述了超薄壁结构海藻酸钙胶囊膜的制备方法及其功能化的研究新进展,重点介绍了利用共挤出毛细管装置制备超薄壁结构的海藻酸钙胶囊膜、利用精蛋白吸附与仿生硅化技术对超薄壁结构海藻酸钙胶囊膜的有机/无机杂化处理,以及利用复合纳米响应性凝胶颗粒的方法和接枝响应性聚合物高分子的方法实现超薄壁结构海藻酸钙胶囊膜的功能化改性等方面的研究现状。     

双乳化-凝胶法制备单分散海藻酸钙微球及其载BSA研究

采用双乳化-凝胶法制备了单分散的海藻酸钙凝胶微球,并通过正交试验系统考察了海藻酸钠浓度、氯化钙浓度、表面活性剂浓度、搅拌速度和油水比对海藻酸钙凝胶微球粒径及形貌的影响。在优化的条件下,制备出了平均粒径为4μm、单分散和球形度好的海藻酸钙凝胶微球。包埋模型药物牛血清白蛋白(BSA)的过程中,以去离子水作为洗涤液洗涤海藻酸钙微球时,BSA的包封率仅为13%左右;当水洗液的pH值为3.2时,BSA的包封率提高到66%左右,载药率可达16%,这是海藻酸钙pH值响应溶胀和BSA与海藻酸盐之间静电作用的结果。微球中BSA的体外释放曲线表明,该系统具有在模拟胃液中释药速率慢、释药量低、模拟肠液中释药迅速的特性。因此,双乳化-凝胶法制备海藻酸钙微球有望成为制备蛋白类药物控释制剂的一种新方法,以达到靶向快速给药的目的。     

基于半互穿凝胶的复合抑尘剂的制备及性能研究

以海藻酸钠为基体,乙酸乙烯酯和丙烯酸为反应单体,利用接枝共聚技术对海藻酸钠进行了分子改性,再加上氯化钙生成的海藻酸钙凝胶进行凝胶半互穿,制备了一种环保、无污染的抑尘剂,通过对抑尘性能进行测试得出抑尘剂润湿性强,抑尘效果好。     

聚丙烯/海藻酸钙复合材料结晶动力学的研究

以海藻酸钙凝胶作为填料,马来酸酐接枝聚丙烯(PP-g-MAH)作为相容剂,通过模压成型工艺,制备了聚丙烯/海藻酸钙复合材料。利用偏光显微镜、差示扫描量热仪等手段对聚丙烯/海藻钙复合材料的结晶结构和结晶动力学进行了研究。结果表明:海藻酸钙凝胶的加入,使复合材料的球晶边缘变得模糊,球晶尺寸下降,数目增多且分布均匀;此外,复合材料的结晶活化能降低,结晶温度和结晶速率常数增加,半结晶时间缩短。     

铜离子改性海藻酸钙纤维的制备及其耐盐性

采用硫酸铜溶液对海藻酸钙纤维进行处理,制备Cu~(2+)改性海藻酸钙纤维。研究了处理工艺条件及纤维的耐盐性能。结果表明:最佳处理工艺为硫酸铜溶液质量分数10%,温度40℃,处理时间60min,得到的Cu~(2+)改性海藻酸钙纤维断裂强度为3.28 cN/dtex,比未改性的纤维提高了24%。经Cu~(2+)改性后,海藻酸钙纤维的耐盐性提高,在食盐溶液中浸泡未发生凝胶化;但纤维受到损伤,纤维断裂强度下降,随着食盐溶液浓度和温度的提高,纤维的损伤越严重。     

海藻酸凝胶性质对蛋白质扩散的影响

通过观察冷冻干燥海藻酸凝胶的断面扫描电镜(SEM)照片与卵清蛋白从海藻酸凝胶中的释放试验,分析了海藻酸凝胶性质对蛋白质在凝胶中扩散的影响。凝胶的SEM照片可见,海藻酸钙的冷冻干燥颗粒内为较大的圆孔,海藻酸锌凝胶内为较小的长孔,表明海藻酸锌高分子链在凝胶颗粒中的体积分率相对较大同时刚性较强;卵清蛋白从海藻酸凝胶颗粒中释放的试验结果表明,由于上述海藻酸锌凝胶的特性,导致海藻酸锌对卵清蛋白扩散阻滞作用相对较强;根据试验数据计算得卵清蛋白在海藻酸钙、海藻酸锌凝胶颗粒中的扩散系数分别为1.19×10-7、0.07×10-7cm2/s,利用阻滞模型计算得海藻酸锌高分子链在凝胶颗粒中体积分率约为海藻酸钙高分子链在凝胶颗粒中体积分率的1.7倍。     

海藻酸钙的制备及其医药领域应用研究

海藻酸钙无毒、无刺激性,且其具有良好的生物相容性、吸湿性及凝胶性等。海藻酸钙可用作包衣材料,以改善制剂的控释性能,可用于药物的控释制剂。本文主要论述海藻酸钙和海藻酸钙复合体系的制备方法,及其在医药领域的应用研究。     

海藻酸钙/改性壳聚糖混纺亲水性纤维敷料的制备及其性能研究

本文以海藻酸钙纤维和改性壳聚糖纤维为原料,通过针刺无纺布工艺制备含有不同比例的改性壳聚糖纤维的海藻酸钙/改性壳聚糖混纺敷料,同时,对制备的复合敷料的吸液性能、抗菌性能、止血性能进行研究。结果显示,海藻酸钙/改性壳聚糖混纺敷料具有很好的吸液性能、抗菌性能以及止血效果,有效的改善了海藻酸钙敷料的性能。     

Comparative Study on Metal Extraction Properties of Empore SDB‐XC and Amberlite XAD‐4 Grafted by Salicylic Acid and its Derivatives via Different Bridges

Abstract

Among commercially available sorbents, aromatic organic crosslinked copolymers allow to consider numerous ways of linking ligands. In this way, the grafting of salicylic acid and of its derivatives (methylene disalicylic acid and aurintricarboxylic acid) via the ketone, amide and diazo bridges on Amberlite^® XAD‐4 resin and Empore? SDB‐XC membrane have been carried out. The modified sorbents thus obtained have been appraised according to their grafing rate and their efficiency to selectively retain different metallic ions versus pH. The grafting of the sorbents permits to obtain pretty good yields. Extraction yield studies have revealed that the supports have the same behavior whatever the ligand grafted via a diazo or an amide bridge. Thus, increase of salicylic acid entity number does not improve the performance of the supports. However, bridge used during grafting seems to have an influence upon the extraction yields observed.     

Functionalization of crosslinked polystyrene by radiation-induced grafting

γ-ray irradiated beads of poly(styrene-divinylbenzene) (PS-DVB) have been graft copoly-merized with polyacrylic acid. Preirradiated PS-DVB beads were refluxed with acrylic acid in water, benzene, or toluene. Percentage of grafting was studied under various reaction parameters like total dose, reaction time, and molar concentration. Effects of reaction media, temperature of reaction, and presence of Mohr salt on the percentage of grafting were also studied. From the swelling property of PS-DVB beads in DMF and dichloro-methane, it appeared that no appreciable cross-linking had occurred in the process of grafting. © 1996 John Wiley & Sons, Inc.     

Immobilization of some biomolecules onto radiation‐grafted polyethylene beads for possible use in immunoassay applications

Functionalization of polyethylene (PE) beads was accomplished via radiation induced graft copolymerization of acrylic acid/acrylamide (AAc/AAm) binary comonomer of different compositions onto such beads. Factors affecting the grafting yield were optimized and the occurrence of the grafted chains was confirmed by following the FTIR spectra of the grafted beads. SEM analyses were used to follow the variation of the morphology of the grafting and immobilization onto PE beads. Some bio‐active molecules such as Follicle‐stimulating hormone (FSH), Luteinizing hormone (LH), Thyroid‐stimulating hormone (TSH), and Prolactin were immobilized to the radiation functionalized PE beads. The parameters may affect the immobilization process such as degree of grafting, temperature, and pH of the coupling buffer and the coupling period were investigated. The obtained results show that the grafting of AAc offers a better immobilization environment than those of AAm and their copolymer. It is found that the highest immobilization degree would be achieved at pH 7 and 37°C for 24 h. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

超大孔聚丙烯酰胺晶胶微球的制备及其生物相容性和吸附性能

利用反相悬浮结合溶剂结晶致孔法制备了具有超大孔隙、球形度良好的聚丙烯酰胺晶胶微球,晶胶微球平均粒径为234.1 mm,孔径约为10～50 mm。采用原位接枝法,将2-丙烯酰胺基-2-甲基-1-丙烷磺酸（AMPSA）接枝到晶胶微球孔隙表面上,得到了带有磺酸基团的阳离子交换晶胶微球。考察了晶胶微球的生物相容性和吸附蛋白质及重金属离子Cu²⁺的性能,结果表明：在大肠杆菌培养液中,添加晶胶微球,对大肠杆菌的生长影响不大。接枝了AMPSA的晶胶微球表现出更强的吸附Cu²⁺的能力,吸附容量达到1.14 mmol·g^-1。同时,接枝后的晶胶微球也具有一定吸附蛋白质的能力,溶菌酶的吸附容量达到54.5 mg·g^-1。因此,该大孔晶胶可望在微生物固定化、生物分离和重金属离子吸附中会发挥更大的作用。     

Preparation and adsorption properties of diethylenetriamine‐modified chitosan beads for acid dyes

This work has demonstrated that the novel chitosan derivative, synthesized by phase transition and grafting diethylenetriamine, has a great potential for the adsorption of acid dyes from aqueous solutions. Four acid dyes with different molecular sizes and structures were used to investigate the adsorption performance of diethylenetriamine‐modified chitosan beads (CTSN‐beads). Results indicated that the adsorption of dyes on CTSN‐beads was largely dependent on the pH value and controlled by the electrostatic attraction. In addition, the adsorption rate (AO10 > AO7 > AR18 > AG25) and adsorption capacities (AO7 > AR18 > AO10 > AG25) were directly related to the molecular size of the dye and the amount of the sulfonate groups on the dye molecules. The equilibrium and kinetic data fitted well with the Langmuir–Freundlich and pseudo‐second‐order model. Furthermore, thermodynamic parameters indicated that the adsorption processes occurred spontaneously and higher temperature made the adsorption easier. The reuse tests indicated that the CTSN‐beads can be recovered for multiple uses. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4090–4098, 2013     

Fouling control in a submerged membrane‐bioreactor by the membrane surface modification

To improve the antifouling characteristics, polypropylene microporous membranes (PPHFMMs) were surface‐modified by the sequential photoinduced graft polymerization of acrylic acid and acrylamide. The grafting density and the grafting chain length, which played important roles in the antifouling characteristics, were controlled in the first and the second step, respectively. The ATR/FTIR results clearly indicated the successful modification on the membrane surface. The static water contact angle of the modified membrane reduced obviously with the increase of the grafting chain length. The contact angle of the acrylic acid modified membranes was lower than that of the acrylamide modified membrane with similar grafting chain length. The grafting chain length increased with the increase of UV irradiation time and monomer concentration. The grafting chain length of poly(acrylic acid) (PAAc) was lower than that of the polyacrylamide (PAAm) under the same polymerization conditions. Pure water flux for the modified membranes increased with the increase of grafting chain length, and had maximums. The antifouling characteristics of the modified membranes in a submerged membrane‐bioreactor (SMBR) were evaluated. The modified membranes showed better filtration performances in the SMBR than the unmodified membrane, and the acrylic acid grafted membrane presented better antifouling characteristics than acrylamide modified membranes. The results demonstrated that the surface carboxyl‐containing membranes were better than the surface amido‐containing membranes. The results of Pearson correlations demonstrated that the PAAc modified membranes with longer grafting chain length had higher flux recoveries, while the PAAm modified membranes with longer grafting chain length had lower flux recoveries. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

催化剂对烷基水杨酸锌树脂性能的影响

以水扬酸和苯乙烯为原料,经Friedel-Crafts 反应合成烷基水杨酸,加入氧化锌整合改性后制备烷基水杨酸锌树脂.通过考察AlCl3、对甲苯磺酸和乙酸锌三种活性不同的催化刺,探讨了树脂软化温度与取代度、显色性能的关系.烷基水杨酸锌树脂的软化温度为54-64℃时,可得到性能优良的无碳复写纸用显色剂.     

辐照接枝丙烯酸改性聚砜超滤膜

采用液相共辐照技术在聚砜超滤膜上接枝丙烯膜，通过改变辐照剂量和丙烯酸单体浓度可以获得具有不同接枝率的改性聚砜膜。实验结果表明，随着接枝率的提高，改性聚砜抗蛋白质吸附污染的能力显著增强，并且认为接枝膜的亲水性提高是膜污染减轻的主要原因。     

Environmentally friendly copolymeric beads of Chlorella vulgaris and poly(methacrylamide) grafted aliginic acid di‐block copolymers for biosorption of zinc ions

The synthesis of biodegradable environmentally friendly copolymeric beads for water treatment biosorption processes is demonstrated. The synthesized poly(methacrylamide) grafted aliginic acid copolymers were characterized using ¹H NMR, Fourier transform infrared spectroscopy, TGA and SEM. The di‐block copolymers showed a morphological change from two‐dimensional layer‐by‐layer structures to three‐dimensional well‐compacted wrinkles as grafting efficiency increased. The copolymeric beads were formed from the di‐block copolymer and algae crosslinked with 5% calcium ions (w/w). These copolymeric beads were then subjected to biosorption investigations for zinc ions as a model heavy metal ion at different pH values and stirring time periods. Batch adsorption experiments showed that the copolymeric beads were effective in zinc ion removal from aqueous solutions with maximum uptake exceeding 89.0 mg g^–1 using higher grafting efficiency copolymeric beads at pH 5.5. Equilibrium pH studies revealed that zinc biosorption was pH dependent and maximum uptake was obtained at pH 5.5. Dynamics studies showed that the biosorption of zinc was rapid with equilibrium attained within 40 min and the data followed pseudo‐second‐order kinetics. The equilibrium biosorption of zinc ions on the copolymeric beads exhibited a Freundlich isotherm fit. © 2012 Society of Chemical Industry