聚乙烯醇-壳聚糖复合海绵的制备及性能

为了进一步提高聚乙烯醇-壳聚糖复合海绵的性能,在聚乙烯醇与甲醛的缩醛化反应过程中加入壳聚糖,并使其与其他原料反应制备聚乙烯醇-壳聚糖复合海绵. 分别改变配方中发泡剂和壳聚糖的含量,合成了一系列组分不同的聚乙烯醇-壳聚糖复合海绵,研究了发泡剂含量和壳聚糖含量对复合海绵结构、吸水能力和膨胀率的影响,并采用扫描电子显微镜对复合海绵的结构与微观形貌进行表征,测试了改性海绵对大肠杆菌和金黄色葡萄球菌的免疫能力. 研究结果表明,选用曲拉通X-405作为发泡剂,当壳聚糖含量为聚乙烯醇质量的10%时,所制备的复合海绵效果最佳,复合海绵具有明显的蜂窝状多孔结构,其吸水率可达到858%. 抗菌实验证明,与纯的聚乙烯醇海绵相比,复合海绵对金黄色葡萄球菌具有较好的免疫能力.     

海藻酸钠海绵的制备及其药物控释性能

通过对海藻酸钠溶液进行冷冻干燥,以氯化钙为交联剂,制备出海藻酸钠海绵,再以此海绵为载体,负载环丙沙星,制得载药海藻酸钠海绵。研究了海藻酸钠溶液质量分数对海绵力学性能与吸水性能的影响,探究其对载药海绵的药物释放的影响。并进一步探索了载药海绵在不同外加电压下的药物释放行为。结果表明,随着海藻酸钠溶液质量分数的提高,所制得的海藻酸钠海绵的吸水率和吸水速度呈现先增加后减小的趋势,当海藻酸钠溶液质量分数为2.5%时,所得的海藻酸钠海绵的吸水率和吸水速度达到最大,药物释放率最高。海绵的药物释放速度和药物释放量随着电压的增大而加快,表明外加电压可以改变载药海绵的药物释放速率和释放量,从而为载药海藻酸钠海绵提供新的药物控释方法。     

壳聚糖/海藻酸钠聚电解质海绵及抗菌功能

将壳聚糖（CS）和海藻酸钠（AL）溶液混合，利用冷冻干燥的方法成功地制备出CSAL聚电解质海绵。利用红外光谱确认了复合海绵中的聚电解质复合行为，同时利用扫描电镜观测到引入海藻酸钠后海绵的孔径增大。吸水性能测试结果显示该聚电解质海绵具有较高的吸水率。引入不同的抗菌剂而表现出特异的抗菌性能，载磺胺嘧啶银的复合海绵能持续抑菌，而载聚乙烯吡咯烷酮-碘的复合海绵具有初始杀菌能力强的特点。     

PVA-g-PNIPA温度敏感凝胶纤维

以过硫酸钾(KPS)为引发剂,以二甲基亚砜为溶剂,通过自由基聚合的方法制备聚乙烯醇(PVA)接枝N-异丙基丙烯酰胺(NIPA)共聚物(PVA-g-PNIPA);用丙酮做凝固浴,通过湿法纺丝工艺和醛交联,制得具有温度响应性的PVA-g-PNIPA凝胶纤维并对其进行缩醛化处理;通过改变缩醛化处理时甲醛的用量,研究了不同缩醛度对PVA-g-PNIPA凝胶纤维的溶胀性能和力学性能的影响.结果表明:所制备的PVA-g-PNIPA凝胶纤维表现出明显的温度响应性能;随着缩醛化程度的增加,PVA-g-PNIPA凝胶纤维的溶胀度和溶胀速率都表现出下降趋势,而其力学性能显著增强.     

生物质石墨烯改性海藻纤维制备与性能

采用湿法纺丝技术将圣泉集团生产的生物质石墨烯浆料与海藻酸钠溶液进行共混纺丝,制备出生物质石墨烯改性海藻纤维,并对其力学性能、吸湿性能、阻燃性能、抑菌性能、远红外性能进行测试。结果表明,随着石墨烯含量的增加,纤维力学强度先增高后下降,当石墨烯含量为0.5%,纤维强度可达1.72cN/dtex。纤维回潮率和极限氧指数(LOI)随石墨烯含量提高而进一步增大,当石墨烯含量为1.5%时,回潮率为23.36%,极限氧指数为41。少量添加石墨烯,纤维呈现较好的抗菌和远红外性能,且随着石墨烯含量的增加,纤维抑菌和远红外性能不断提高,当石墨烯添加量为1.5%时,纤维对金黄色葡萄球菌、大肠杆菌及白色念珠菌的抑菌率均大于99%,远红外温升为3.3℃,发射率0.9。     

PLA/PVA/SA复合纱线的制备与表征

将聚乳酸(PLA)短纤纱与聚乙烯醇(PVA)/海藻酸钠(SA)混合水凝胶溶液复合,经冷冻、解冻、浸泡和干燥后获得水凝胶复合纱线,并进一步进行矿化处理。通过扫描电子显微镜(SEM)、能谱(EDS)、红外光谱(FTIR)、吸水率和拉伸测试对试样的形貌结构、元素组成、基团变化、亲水性和力学性能表征分析。结果表明:复合纱线中水凝胶成功披覆纱线表面并渗透入纱线内部,在纱线表面形成三维微孔结构;经矿化处理后,纱线表面沉积大量磷灰石,且磷灰石含量多于纯PLA短纤纱;与纯PLA短纤纱相比,复合纱线吸水率增加约50%,力学性能增强。该制备所得复合纱线具有良好的体外生物活性、吸水性和力学性能,可用于构建组织工程支架材料。     

复配增塑剂对聚乙烯醇薄膜性能的影响

以甘油和乙二醇为复配增塑剂,研究了复配增塑剂对聚乙烯醇的熔融和结晶行为的影响;采用熔融共混法制备聚乙烯醇薄膜,考察了复合增塑剂对薄膜力学性能、水溶性能的影响.结果表明:复配增塑剂质量百分含量在10%~30%时可有效降低聚乙烯醇的熔融温度和结晶温度;当其在30%时,薄膜的力学性能达到最优,拉伸强度为24.9 MPa,断裂伸长率为380%;薄膜的溶解失重率与时间呈良好的线性关系.     

聚乙烯醇缩丁醛合成工艺研究

研究了聚乙烯醇(PVA)和正丁醛在盐酸催化条件下,沉淀法合成聚乙烯醇缩丁醛(PVB).考察了m(正丁醛):m(PVA)、催化剂用量、乳化剂用量、低温反应时间(t_L)、高温反应温度(T_H)以及高温反应时间(T_H)对缩醛反应的影响,结果表明,最佳合成工艺条件为:m(正丁醛):m(PVA)为2.2 1,催化剂的用量为13%(以正丁醛和PVA总质量计),乳化剂用量为1.9%(以正丁醛和PVA总质量计),在3~7℃反应3 h,45℃反应1 h的条件下,制备得到的聚乙烯醇缩丁醛的缩醛度可达到88.47%.     

PVDF中空纤维复合膜的制备及其性能研究

研究聚偏氟乙烯(PVDF)中空纤维膜复合膜的制备与性能．扫描电镜和红外光谱等试验结果表明：聚乙烯醇(PVA)在PVDF中空纤维膜表面与戊二醛发生缩醛化反应，形成了复合膜；浸泡时间、PVA浓度、反应时间、温度等反应条件对于复合膜的性能有着较为明显的影响，随着反应温度的提高、反应时间的延长．缩醛化反应充分，膜通量下降明显，膜截留率升高．     

淀粉基/聚乙烯醇复合薄膜的制备及性能研究

以淀粉和聚乙烯醇为主要原料,丙三醇为增塑剂,通过流延成膜法制备淀粉基/聚乙烯醇生物薄膜.考察了料液浓度、原料配比及增塑剂含量对复合薄膜力学性能、耐油性能以及结晶性能的影响.研究结果表明:复合薄膜的最佳料液浓度为7.5%;聚乙烯醇的含量越高,共混膜的综合性能越好;当淀粉、聚乙烯醇与增塑剂的质量比为6∶6∶4时,制备的淀粉基/聚乙烯醇复合薄膜的力学性能最好,其拉伸强度和断裂伸长率分别达到13.3MPa和160%;偏光显微镜测试结果表明其相应材料的结晶性能最佳.     

海藻酸钠/聚乙烯醇/羟基磷灰石复合纤维制备工艺及其性能

以溶液纺丝法制备了海藻酸钠/聚乙烯醇/羟基磷灰石复合纤维,采用正交试验法和单因素分析法对复合纤维制备工艺与断裂强度和镉离子吸附量的关系进行研究。结果表明,SA与PVA质量分数为6%、SA与PVA质量比为4∶1、凝固浴CaCl2质量分数为2%、凝固浴温度为60℃、纺丝头牵伸比为2倍时纤维的吸附量最大。随着羟基磷灰石含量的增加,复合纤维对镉离子吸附量大幅度提高。     

维氯纶缩醛化的研究

维氯纶为具有阻燃性的改性维纶;缩醛化是它的重要工艺过程,本工作用正交设计的实验友法,考察了缩醛化条件对缩醛度的影响和不同缩醛度对纤维性能的影响,并从纤维的几个重要实用指标出发,确定了维氯纶的最佳缩醛化条件,为实现我国维氯纶的工业化生产提供了必要的工艺依据。     

海藻酸钠-明胶-PVA包埋法固定化酵母菌吸附铅

利用海藻酸钠,明胶,PVA固定化酵母菌吸附金属铅离子,实验结果表明,包埋剂海藻酸钠、明胶、PVA浓度各为1%,pH值为4.5,Pb2 离子初始浓度为0.9652mmol·L-1,酵母菌浓度为5g/L时,在室温下吸附1h,吸附效果最佳,其吸附模型符合Langmuir等温吸附方程。     

固定化硝化细菌去除水体中氨氮的研究

研究了以聚乙烯醇(PVA)为骨架载体,添加适量的添加剂,利用活性炭吸附硝化细菌,采用包埋法制作固定硝化细菌小球,去除水体中氨氮的方法.通过实验,发现1%的海藻酸钠(占PVA的凝胶百分比),4%SiO2,0.3%CaCO3作为添加剂,PVA包埋硝化细菌的成球效果较好,小球表现有较佳的机械强度以及传质性能.同时用正交实验确定了在PVA质量浓度为10%,活性炭含量占PVA凝胶的2%,交联时间32h及包菌量的值为1∶2的情况下,包埋的固定化小球去除氨氮的效率最高,42 h就可以达到80%以上,去除氨氮效率强.     

Fabrication and Characterization of One Interpenetrating Network Hydrogel Based on Sodium Alginate and Polyvinyl Alcohol

One interpenetrating network hydrogel based on sodium alginate(SA) and polyvinyl alcohol(PVA) was synthesized by combining the raw materials of PVA and SA with the double physical crosslinking methods of freezing thawing and Ca~(2+) crosslinking. The PVA-SA composite hydrogel have been characterized by scanning electron microscopy for surface morphology, infrared spectroscopy for investigating the chemical interactions between PVA and SA, X-ray diffraction for studying the PVA-SA composite structure property and thermal gravimetric for understanding the PVA-SA composite thermal stability. The swelling behavior and the degradation rate of the PVA-SA composite hydrogel were studied in simulated gastrointestinal fluid. Using bovine serum albumin(BSA) and salicylic acid as the model drugs, the release behavior of the PVASA composite hydrogel on macromolecular protein drugs and small molecule drug were evaluated. The results showed that the water absorption and degradation ability of the PVA-SA composite hydrogel was much better compared to the pure SA hydrogel or pure PVA hydrogel. The hydrogel exhibited remarkable pH sensitivity and the network was stable in the simulated intestinal fluid for more than 24 h. With the advantages such as mild preparation conditions, simple method, less reagent and none severe reaction, the PVA-SA composite hydrogel is expected to be a new prosperous facile sustained drug delivery carrier.     

微生物胞外多糖SM-A87 EPS固定化条件优化及对Pb(II)吸附的研究

为了解决微生物胞外多糖(exopolysaccharide, EPS)Wangia profunda SM A87 (SM A87 EPS)的分离问题,选用环境友好材料聚乙烯醇(polyvinylalcohol, PVA)和海藻酸钠(sodium alginate,SA),通过正交试验设计对微生物胞外多糖SM A87 EPS固定化条件进行了优化,并对固定化SM A87 EPS小球的吸附效能进行了初步研究。以PVA、SA、EPS的质量分数及硬化时间为因素,以Pb(II)去除率为主要指标,成球性、多糖溶出率、耐酸性为辅助指标,获得了固定化EPS小球的最优配比为m(PVA)∶m(SA)∶m(EPS)∶m(H2O)=80∶20∶1∶1000,硬化时间为16h。通过批次实验,研究了固定化小球用量、pH值、吸附时间对固定化EPS小球吸附Pb(II)的影响。结果表明固定化小球对Pb(II)的去除率随吸附剂用量的增加而升高;pH值对固定化小球吸附Pb(II)有影响;浸泡组的吸附速率大于干燥组的吸附速率。Langmuir等温线能够较好地拟合固定化EPS小球吸附Pb(II)的热力学过程,相关回归系数为0.954,最大理论吸附量为82.64mg／g。准二级动力学模型能够较好地拟合固定化EPS小球吸附Pb(II)的动力学过程,吸附过程受两个以上的阶段控制。     

Electrospinning and rheological behavior of poly (vinyl alcohol)/collagen blended solutions

Poly(vinyl alcohol)/collagen (PVA/COL) micro-nanofibers were successfully prepared by electrospinning process. Water, green, and non-toxic was used as the solvent. The electrospun mats consisted of micro-nanoscale fibers with mean diameter ranging from approximately 363 nm to 179 nm. It was observed that the mean diameters of PVA/COL electrospun fibers decreased with increasing collagen content. The effects of PVA/COL blending ratio on the rheological behavior of PVA/COL blended solutions were investigated by rotate rheometer. It was found that PVA/COL blended solutions behaved as Non-Newtonian fluids. With increasing collagen content, the Non-Newtonian index (n) of PVA/COL blended solutions decreased. Meanwhile, a linear relationship was found between the Non-Newtonian index (n) and the mean diameters of the PVA/COL micronanofibers. The chemical structures of PVA/COL electrospun fibers were also characterized by FTIR.     

Preparation and characterization of nano-hydroxyapatite/polyvinyl alcohol gel composites

Nano-hydroxyapatite reinforced poly(vinyl alcohol) gel (nano-HA/PVA gel) composites has been proposed as a promising biomaterial, especially used as an articular cartilage repair biomaterial. In this paper, nano-HA/PVA gel composite was prepared by in situ synthesis method and incorporation with freeze-thaw cycle process. The microstructure and morphology were investigated by X-ray diffraction, TEM, SEM and FTIR. The results showed that the size of HA particles synthesized in PVA solution was on the nanometer scale. Both the size and crystallinity of HA particles synthesized in PVA solution decreased compared with that of HA synthesized in distilled water. The nano-HA particles were distributed in PVA matrix uniformly due to the effect of PVA solution as a dispersant while low content of HA particles in the composites. On the contrary, with high content of nano-HA particles in the composites, the particles tended to aggregate. The result of FT-IR analysis indicated that the chemical bond between nano-HA particles and PVA matrix existed. The conformation and degree of tacticity of PVA molecule changed because of the addition of HA particles. Furthermore, the interfacial strength of the composites was improved due to the interaction between nano-HA particle and PVA matrix and this was beneficial to improving the mechanical properties of the composites.     

功能性PVA／PA6复合纳米纤维的制备及固定化酶研究

利用静电纺丝制得PVA／PA6复合纳米纤维,再通过环氧化反应制备功能性PVA／PA6复合纳米纤维并以之为载体固定过氧化氢酶．实验结果表明,PVA／PA6复合纳米纤维在合理的反应时间内形态稳定;固定后的过氧化氢酶体现出更好的存贮稳定性;经过对酶催化反应进行动力学分析,分别得到自由酶和固定化酶的Vmax值和Km值,动力学参数体现了载体与固定化酶之间良好的生物亲和性．     

Characterization of Microcystis Aeruginosa immobilized in complex of PVA and sodium alginate and its application on phosphorous removal in wastewater

Based on ecological niche theory, Microcystis Aeruginosa(MA) immobilized in the complex of polyvinyl alcohol(PVA)and sodium alginate(SA) crosslinked by CaCl2, was treated as a new kind of special species, and its properties were investigated.Chlorophyll a was used to characterize the bioactivity of the immobilized MA. Results reveal that the gel beads have mechanical strength and chemical stability even under non-sterile harsh conditions, which may be attributed to the rarely seen structure(including three different layers: dense surface, tubular-shaped divergent structure and honeycomb crystal lattice layer) of the immobilized MA determined by scanning electron microscope(SEM). SEM also displays that more quantity of MA is attached to the inwall after cultivation, which demonstrates that the MA within beads maintains high bioactivity. Removal capacities on phosphorous(P) removal in wastewater in the presence and absence of the BG-11 medium were examined, and the removal ratios are 80.3% and76.7%, respectively, which indicates that the beads without providing ample nutrients still have high capacity of P removal. In addition, control experiment, utilizing polyvinyl alcohol and sodium alginate(PVA-SA) beads without immobilized MA,demonstrates that MA within beads plays the key role in absorbing P.