肝素钠/聚乙烯醇复合水凝胶的制备与性能

通过循环冷冻-解冻法,制成了肝素钠/聚乙烯醇(HS/PVA)复合水凝胶材料。 探讨了不同质量分数肝素钠对复合水凝胶材料的可见光透过率、含水率、亲水性、力学性能以及肝素钠释放量的影响。 结果表明,复合水凝胶的可见光透过率为92%以上,溶胀平衡的含水率为72%~78%,亲水性较纯PVA水凝胶有所提升,拉伸强度和断裂伸长率都稍有下降。 细胞粘附实验结果表明,适量的肝素钠的释放可以达到减少细胞粘附的效果。 这种HS/PVA复合水凝胶材料有望用作人工角膜中心区材料。     

化学-物理法制备聚乙烯醇/壳聚糖/纳米羟基磷灰石复合水凝胶及其性能

采用化学 物理交联法制备了聚乙烯醇/壳聚糖/纳米羟基磷灰石（PVA/CS/n-HA）复合水凝胶材料。 通过对比其含水率、拉伸强度、红外光谱和TG谱图,探讨了PVA含量及戊二醛加入量对材料性能的影响。 结果表明,m(PVA)∶m（CS+n-HA）=5∶1,戊二醛质量分数为2%时,复合水凝胶材料具有较好的综合性能：含水率为82.0%、拉伸强度为2.14 MPa、断裂伸长率为343.26%;同步热分析表明,25~140 ℃,仅存在水分的蒸发,直至360 ℃材料才发生分解,说明材料的热稳定性良好;红外分析表明,CS与戊二醛发生了交联反应。     

多孔β-磷酸三钙/壳聚糖/聚乙烯醇复合水凝胶的制备与性能

以NaCl为致孔剂,采用溶盐致孔法制备了多孔β-磷酸三钙/壳聚糖/聚乙烯醇（β-TCP/CS/PVA）复合水凝胶材料。 通过对比其含水率、溶胀比、拉伸强度、X射线衍射谱图、SEM和热重分析曲线,探讨了在相同环境下壳聚糖与β-磷酸三钙（β-TCP）的不同用量对聚乙烯醇(PVA)的结晶度以及对材料性能的影响。 此复合材料含水率为70%~76%。 当壳聚糖与β-TCP的质量比为2∶8时,复合材料的拉伸强度为0.56 MPa,断裂伸长率达到370%,其较好的力学性能,足以承受正常人眼压,可用作人工角膜周边支架材料。     

基于聚乙烯醇/金纳米棒复合凝胶膜的Hg~(2+)传感器构建及应用

利用种子生长法制备金纳米棒,将其分散于聚乙烯醇溶液中,以戊二醛为交联剂,制备了对Hg2+有光学响应性的化学交联聚乙烯醇/金纳米棒(PVA/GNRs)复合凝胶膜。利用紫外-可见光谱法表征了该复合凝胶膜对Hg2+的传感性能。结果表明,在还原剂抗坏血酸的辅助下,PVA/GNRs凝胶对Hg2+有良好的光学响应和选择性,测量线性范围为0.1~3.0μmol/L,相关系数为0.997,响应时间为5 min。以PVA/GNRs复合凝胶膜构建的光学传感器具有制备方法简便、稳定性高等优点,可用于水样中微量Hg2+的检测。     

Swelling Resistance and Mechanical Performance of Physical Crosslink‐Based Poly(Vinyl Alcohol) Hydrogel Film with Various Molecular Weight

The present work aimed to develop polyvinyl alcohol (PVA) hydrogel films with physically crosslinking through controllable entanglement density of the polymer chains. The viscoelasticity of PVA aqueous solutions was investigated over a broad range in molecular weight. The chain length between the crosslinks in the hydrogel ( $\overline{M_e}$) and entanglement density was determined by the plateau modulus (G'). The value of ( $\overline{M_e}$) increased with the PVA molecular weight, which can be attributed to the enhanced entanglement associated with the hydrogen bonds between inter‐ and interchains. The melting and crystallization of the transparent PVA hydrogel films showed that the crystallinity was below 30%, which indicated that microcrystallites formed. Therefore, the entanglement effect and microcrystallization enhanced the stable crosslinked hydrogel network, which further improved by an increase in the molecular weight. Altogether, the PVA with the molecular weight higher than 88,000 g/mol can be envisioned as a promising material for preparing the hydrogel film possessing excellent performance. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 1673–1683     

Cellulose Nanocrystals (CNCs) Induced Crystallization of Polyvinyl Alcohol (PVA) Super Performing Nanocomposite Films

This study is aimed to explore the properties of cellulose nanocrystals (CNC)/polyvinyl alcohol (PVA) composite films with and without 1,2,3,4‐butane tetracarboxylic acid (BTCA), a nontoxic crosslinker. CNC and CNC‐PVA nanocomposite films are prepared using solution‐casting technique. Differential scanning calorimetry (DSC) analyses show that crosslinking increased the glass transition temperature but reduced the melting temperature and crystallinity. Furthermore, high CNC concentrations in the PVA matrix interfere with PVA crystallinity, whereas in specific ratio between CNC and PVA, two different crystalline structures are observed within the PVA matrix. Film surfaces and fracture topographies characterized using scanning electron microscope indicate that at certain CNC‐PVA ratios, micron‐sized needle‐like crystals have formed. These crystalline structures correlate with the remarkable improvement in mechanical properties of the CNC‐PVA nanocomposite films, that is, enhanced tensile strain and toughness to 570% and 202 MJ m^?3, respectively, as compared to pristine PVA. BTCA enhances the tensile strain, ultimate tensile stress, toughness, and modulus of CNC films compared to pristine CNC films. Water absorption of crosslinked CNC and CNC‐PVA nanocomposite films is significantly reduced, while film transparency is significantly improved as a function of PVA and crosslinker content. The presented results indicate that CNC‐PVA nanocomposite films may find applications in packaging, and though materials applications.     

聚乙烯醇缩对甲酰基苯偶氮变色酸析相液-固萃取镍的研究

报道了高分子显色剂聚乙烯醇缩对甲酰基苯偶氮变色酸做萃取剂时,Ｎｉ＾２＋等常见过渡金属离子的非有机溶剂液－固萃取行为和影响萃取的各种因素,特别是对高分子显色剂的结构与分析性能的关系做了系统比较研究,并对萃取机理作了初步探讨。     

Biocompatibility Study of Electrospun Nanocomposite Membranes Based on Chitosan/Polyvinyl Alcohol/Oxidized Carbon Nano-Onions

In recent decades, the number of patients requiring biocompatible and resistant implants that differ from conventional alternatives dramatically increased. Among the most promising are the nanocomposites of biopolymers and nanomaterials, which pretend to combine the biocompatibility of biopolymers with the resistance of nanomaterials. However, few studies have focused on the in vivo study of the biocompatibility of these materials. The electrospinning process is a technique that produces continuous fibers through the action of an electric field imposed on a polymer solution. However, to date, there are no reports of chitosan (CS) and polyvinyl alcohol (PVA) electrospinning with carbon nano-onions (CNO) for in vivo implantations, which could generate a resistant and biocompatible material. In this work, we describe the synthesis by the electrospinning method of four different nanofibrous membranes of chitosan (CS)/(PVA)/oxidized carbon nano-onions (ox-CNO) and the subdermal implantations after 90 days in Wistar rats. The results of the morphology studies demonstrated that the electrospun nanofibers were continuous with narrow diameters (between 102.1 nm ± 12.9 nm and 147.8 nm ± 29.4 nm). The CS amount added was critical for the diameters used and the successful electrospinning procedure, while the ox-CNO amount did not affect the process. The crystallinity index was increased with the ox-CNO introduction (from 0.85% to 12.5%), demonstrating the reinforcing effect of the nanomaterial. Thermal degradation analysis also exhibited reinforcement effects according to the DSC and TGA analysis, with the higher ox-CNO content. The biocompatibility of the nanofibers was comparable with the porcine collagen, as evidenced by the subdermal implantations in biological models. In summary, all the nanofibers were reabsorbed without a severe immune response, indicating the usefulness of the electrospun nanocomposites in biomedical applications.     

杂多酸/聚乙烯醇复合膜的制备及光催化性能研究

合成了过渡金属取代的硅钨酸盐K₆SiM(H₂O)W₁₁O₃₉(M=Co、Ni、Cu,简称为SiMW₁₁),利用硅钨酸(H₄SiW₁₂O₄₀·nH₂O,简称为SiW₁₂)与SiMW₁₁做母体,分别将它们负载于聚乙烯醇(polyvinyl alcohol,PVA)上,制成一系列杂多酸/聚乙烯醇复合膜光催化剂,利用IR、SEM进行了表征.以高压汞灯为光源,分别研究了SiW₁₂/PVA、SiCoW11/PVA、SiNiW₁₁/PVA、SiCuW₁₁/PVA复合膜对有机染料甲基橙的光催化脱色,它们都具有很高的催化活性,60 min内对甲基橙的脱色率均可达到90%以上,其中SiW₁₂/PVA复合膜效果最好,12 min内脱色率达100%.提高SiW₁₂负载量可有效提高膜的光催化活性,当SiW₁₂与PVA质量比为1:1时催化活性最高.     

Application of Polyvinyl Alcohol (PVA)/Carboxymethyl Cellulose (CMC) Hydrogel Produced by Conventional Crosslinking or by Freezing and Thawing

Hydrogels for this study were prepared from a mixture of PVA and CMC using three different techniques, i.e., freezing and thawing, electron‐beam irradiation or combined freezing and thawing and electron beam irradiation. A comparative study between the three techniques was carried out in terms of gel fraction (%) and swelling (%). It was found that the physical properties of the hydrogel were improved when the combination of freezing and thawing and irradiation were used rather than just freezing and thawing, or irradiation only. The effects of temperature and soil fertilizers on swelling (%) were examined to evaluate the usefulness of the hydrogel as a super absorbent in the soil. It was found that the swelling ratio increased as the composition of CMC increased in the blend. Hence, the blend having the composition 80/20 (CMC/PVA) was used as a super absorbent in the soil for agriculture. Moreover, the water retention increased in the soil containing this hydrogel. Thus, this type of hydrogel can be used to increase water retention in desert regions.     

Designing Polyaniline (PANI) and Polyvinyl Alcohol (PVA) Based Electrically Conductive Nanocomposites: Preparation,Characterization and Blood Compatible Study

Novel electrically conducting and biocompatible composite hydrogel materials comprising of poly (aniline) (PANI) nanoparticles dispersed in a poly (vinyl alcohol) (PVA) – g–poly (acrylic acid) (PAA) matrix were prepared by in situ polymerization of aniline. The prepared ionic hydrogels were evaluated for their water uptake capacity in distilled water. While structural insights into the synthesized polymer was sought by Fourier Transform Infrared (FTIR) spectroscopy and X–Ray Diffraction (XRD) techniques, morphology and dimension of PANI particles embedded into the colored optically semi–transparent polymer films were evaluated by Scanning Electron Microscopy (SEM) analysis and Transmittance Electron Microscopy (TEM) while thermal behavior of composite hydrogel was investigated by Differential Scanning Calorimetry (DSC). Electrical conductivity of composite hydrogels containing different PANI percentage was determined by LCR. Considering the potential of electrically conductive nanocomposites materials in biomedical applications the in vitro blood compatibility of nanocomposites was investigated by employing several in vitro tests.     

壳聚糖/聚乙烯醇共混膜在织物化学镀中的应用

天然高分子壳聚糖(CS)与聚乙烯醇(PVA)共混后存在强烈的氢键作用能够促进二者相容,形成互穿网络(IPN)结构的CS/PVA二元共混膜。 通过傅里叶红外(FT-IR)和强力测试对共混膜结构及拉伸强力性能进行了表征。 利用掺杂少量氯化钯的CS与PVA共混液的成膜性能,在涤纶织物表面预制一层具有自催化活性的薄膜,并对经过处理后的涤纶织物进行化学镀镍研究。 采用扫描电子显微镜(SEM)、热重分析(TG)、电磁屏蔽效能测试和水洗牢度测试,分别对织物表面形貌、热稳定性、电磁屏蔽性能和结合牢度进行测试。 结果表明,CS与PVA共混液处理后的涤纶织物,经化学镀镍能获得表面均匀致密、导电性优良、与织物结合力良好的镀层。     

Fabrication and Properties of Porous Collagen/Hyaluronic Composite Scaffolds Containing Nano-Bioactive Glass for Tissue Engineering

In this work, nano-structured scaffolds were designed for tissue engineering using collagen, hyaluronic acid (HA) and nano-bioactive glass (NBAG) as their main components. The scaffold was prepared via freeze-drying method and the properties including morphology, porosity, compressive strength, swelling ratio and cytotoxicity in-vitro, were also evaluated. The composite scaffolds showed well interconnected macropores with the pore size of ranging from 100 to 500 μm. The porosity percent and swelling ability were decreased with the introduction of NBAG into the collagen/HA hydrogel; however, the compressive strength was enhanced. The cytotoxicity in-vitro study shows that the collagen-HA/NBAG scaffolds have good biocompatibility with improving effect on fibroblastic cells growth. It could be concluded that this scaffold fulfills the main requirements to be considered as a bone substitute.     

酯化交联聚乙烯醇膜用于渗透气化法分离EtoH／H2O的研究

合成了一系列磷酸和二元羧酸酯化交联改性的聚乙烯醇(PVA)膜,研究了它们用于水-乙醇混合液的渗透气化分离规律。磷酸改性的PVA膜具有较大的通量,当料液浓度为50%时,通量可达1200g/m~2·hr.,分离系数α_(H_2O/EtOH)=10。丙二酸改性PVA膜在料液浓度为50%时,通量可达800g/m~2·hr.,且α_(H_2O/EtOH)=18。并作了这两种膜的通量和分离系数随料液浓度的变化曲线。草酸交联的PVA膜具有较高的分离系数,但通量很小。求出了水、乙醇及总的表现渗透活化能。     

含胍基交联聚乙烯醇的合成及其对胆红素吸附性能研究

通过将胍基固载到交联聚乙烯醇水凝胶上制备了新型亲水性胆红素吸附剂,该类吸附剂对胆红素具有良好的吸附性能和较高的吸附效率.交联聚乙烯醇对胆红素的吸附率随着载体的交联度、离子浓度以及白蛋白与胆红素质量比的增加而降低;胍基固载量的提高可以增加吸附剂对胆红素的吸附性能.     

聚乙烯醇基水凝胶聚合物电解质超级电容器的研究

以2-丙烯酰胺基-2-甲基丙磺酸（AMPS）作引发剂引发交联聚乙烯醇（PVA）-戊二醛（GA）制备水凝胶聚合物电解质并组装成超级电容器.分别由红外光谱、交流阻抗、循环伏安与恒电流充放电曲线测定该凝胶聚合物电解质及超级电容器的电化学性能.结果表明,该聚合物电解质电导率可达1.23 mS/cm（室温）.而且,以1.0 g AMPS引发0.05mL GA（5 %）与1.0 g PVA交联,制得的凝胶聚合物电解质超级电容器比电容可达139F/g,50次充放电后其值仍于80%以上.     

Fabrication of Sulfated Heterosaccharide/Poly (Vinyl Alcohol) Hydrogel Nanocomposite for Application as Wound Healing Dressing

Nowadays, natural polysaccharides-based hydrogels have achieved promising results as dressings to promote skin healing. In the present study, we prepared a novel hydrogel nanocomposite with poly(vinyl alcohol) (PVA) and sulfated heterosaccharide (UF), named UPH. The SEM results showed that the UPH had dense porous structures with a high porosity and a specific surface area. The UPH had a good swelling property, which can effectively adsorb exudate and keep the wound moist. The in vitro experiments results showed that the UPH was non-cytotoxic and could regulate the inflammatory response and promote the migration of fibroblasts significantly. The phenotypic, histochemistry, and Western blot analyses showed UPH treatment accelerated the wound healing and recovery of skin tissue at wound sites in a C57BL/6 mouse model. Furthermore, the UPH could promote the inflammation process to onset earlier and last shorter than that in a normal process. Given its migration-promoting ability and physicochemical properties, the UPH may provide an effective application for the treatment and management of skin wounds.     

PVA/Gel水凝胶的电刺激可逆弯曲偏转行为研究

制备不同比例的聚乙烯醇/明胶水凝胶,在直流电场作用下,测试聚乙烯醇/明胶水凝胶在不同温度和不同浓度Na2CO3溶液中的电刺激弯曲偏转行为,绘制聚乙烯醇/明胶水凝胶弯曲偏转角随时间的变化曲线,考察了可逆弯曲偏转变化的周期性。     

丝素蛋白纤维/聚N-异丙基丙烯酰胺复合水凝胶的性能

以丝素蛋白纤维为填充材料,采用自由基聚合的方法制备复合聚N-异丙基丙烯酰胺(PNIPPAm)水凝胶,研究复合水凝胶的黏弹性能、溶胀性能和反复溶胀-收缩性能。结果表明:丝素蛋白纤维的加入改善了复合水凝胶的力学性能,其平衡溶胀率不仅与温度有关,而且与丝素蛋白纤维的含量有关。此外,处在表面的丝素蛋白纤维与水凝胶之间存在间隙,在反复溶胀-收缩过程中可以作为输水通道,有利于水分子进出,提高了PNIPPAm水凝胶对温度的响应速率并使其溶胀-收缩重复性更好。     

聚乙烯醇对光还原Ni~(2+)制备纳米Ni性能及染料敏化制氢的影响

采用染料曙红-Y(EY)作为敏化剂将Ni~(2+)光还原制备纳米Ni.在该反应体系中,不加入PVA时,光还原所得到的纳米Ni为球状粒子;而加入PVA,由于其模板导向作用,多数纳米镍呈现棒状.吸附在Ni表面的PVA能够促进光生电子从EY向棒状镍转移,从而提高其染料敏化制氢的活性和稳定性.