海藻酸钠及其共混溶液的流变性研究

研究了海藻酸钠溶液,海藻酸钠与羟甲基纤维素、丙三醇、明胶、粒子填充剂等共混溶液的流变性能。结果表明:海藻酸钠溶液属于切力变稀的非牛顿流体;随溶液浓度的提高,粘流活化能增加;海藻酸钠相对分子质量增大,其溶液的结构粘度指数增大。海藻酸钠共混溶液的表观粘度随羟甲基纤维素的加入而增大;随明胶和丙三醇的加入而减小;随粒子填充剂的加入,先增加后减小。     

三元复合驱组分协同效应分析

本文通过实验方法,研究了碱、表面活性剂、聚合物三者浓度变化对界面张力、三元体系粘度、吸附量的影响规律和影响机理。研究表明,碱浓度的增加可以有效降低聚合物和表面活性剂的吸附量;随着碱浓度的不断增大,界面张力呈现出先增大后减小的趋势;随着碱浓度的增大,聚合物粘度呈现出先减小后增大的趋势,表面活性剂浓度的增大会使聚合物粘度不断增大,但两者对于溶液粘度的影响十分微小,基本可以忽略。     

落葵多糖粘度影响因素的研究

本实验主要从落葵中提取而得的多糖进行粘度的研究,分别在不同的浓度、不同的温度、不同的pH值、不同的电解质溶液的条件下测定多糖溶液的粘度变化情况,从而得出对落葵多糖粘度影响较为显著的因素。结果：落葵多糖的粘度随温度升高而减小,随浓度、pH值增大呈锯齿状变化,不同电解质对其影响不同,其中随Na^＋浓度增大的变化比较不规则,随着心和Ca^2＋浓度的增大而变大,且随K^＋的变化幅度比较大,随Ca^2＋的变化比较平稳。     

9：1的纤维素／甲壳素黄原酸酯溶液流变性能的研究

探讨了9：1的纤维素／甲壳素黄原酸酯共混溶液流变性能的影响因素，如溶液浓度和温度对共混溶液非牛顿指数、结构粘度指数、零切粘度等的影响。随着溶液浓度的增加和温度的降低，纤维素／甲壳素黄原酸酯溶液的非牛顿指数随之减小，而结构粘度指数、零切粘度随之增大。溶液的粘流活化能高于传统的粘胶。     

甘油对明胶溶液性能的影响研究

明胶是一种生物高聚物,常以甘油为增塑剂,被广泛用于制备膜材料。本文考察了甘油浓度对不同道次明胶水溶液的性能影响。在明胶用量一定时,设置甘油与明胶不同配比探讨甘油对不同道次明胶溶液性能的影响。研究结果表明:随着甘油加入量的增加,各道次明胶溶液的凝冻强度变化不明显,而勃氏粘度增大较显著。因此,在保证明胶凝冻强度一定的情况下,甘油可以作为明胶材料的增塑剂。     

粘度下降值的探讨

本文探讨了明胶溶液粘度下降值(简称“粘降值”)与培养时间的关系,并对在同一温度条件下,不同浓度的明胶溶液粘降值与培养时间的关系进行了比较。还测试了粘度下降过程中细菌生长情况。     

高相对分子质量PAN纺丝溶液的流变性质

研究了聚丙烯腈 (PAN )纺丝溶液的浓度、温度及聚合物相对分子质量对纺丝溶液的 lgηa ～lgγ流动曲线、粘流活化能、非牛顿指数和结构粘度指数的影响。结果表明 :高相对分子质量聚丙烯腈纺丝溶液具有明显的非牛顿性 ,结构粘度指数随纺丝溶液浓度的升高 ,PAN相对分子质量的增大而增大 ,随纺丝溶液温度的升高、聚合物相对分子质量和浓度的降低而减小。纺制高性能的高相对分子质量PA N纤维宜采用较低的溶液浓度和较高的纺丝温度。     

三文鱼皮明胶的制备及其性能的研究

本文通过酸碱法对三文鱼皮进行预处理,制备了三文鱼皮明胶。研究分析了碱处理时间和浓度、酸处理时间和浓度对明胶产率和粘度的影响规律;测定了三文鱼皮明胶的成分、氨基酸组成、相对粘度。通过紫外光谱、红外光谱、X-射线衍射对其结构进行了分析。     

聚合物溶液流变曲线及粘温特性研究

用长庆油田北三区处理后清水、聚丙烯酰胺配制了聚合物母液和目的液,聚合物母液浓度5000mg/L、目的液浓度2000mg/L,测量温度为10~60℃,剪切速率为1~100s~(-1),考察了剪切速率、温度对不同浓度聚合物的流变性、粘度影响。结果表明,聚合物溶液的粘度随剪切速率的增大不断降低,同一剪切速率下聚合物溶液的表观粘度随温度的升高也有所下降,随着测量温度的升高,聚合物溶液的屈服应力逐渐降低,稠度系数K逐渐增大而流变行为指数逐渐减小,在实际测量温度范围内,聚合物溶液属于非牛顿流体,体现出典型的屈服-假塑性流体特性,剪切速率对聚合物溶液的粘度值影响很大,测量温度对粘度值的影响较小。     

聚酰胺酸溶液的流变性能研究

采用锥板粘度计研究了聚酰胺酸溶液的流变性能及其粘度的影响因素。结果表明:聚酰胺酸溶液属于非牛顿假塑性流体,还具有负触变性流体的特征。聚酰胺酸溶液的粘度随剪切速率的增加而减小,随浓度的增加而增大,随温度的升高而降低,随存放时间的延长而下降;质量分数为15％的聚酰胺酸溶液的粘流活化能为20．83 kJ／mol。     

甲壳胺/乙酸溶液表观粘度的影响因素

在低剪切速率下,研究了甲壳胺的浓度、溶液静置时间、溶液温度及溶剂乙酸浓度对甲壳胺/乙酸溶液表观粘度的影响。结果表明:甲壳胺/乙酸溶液的表观粘度随甲壳胺浓度的增加而上升,随溶液温度的上升而降低,随乙酸浓度的增加有所降低。配制甲壳胺/乙酸纺丝原液时,需现用现配,甲壳胺质量分数4.5%,乙酸质量分数2.0%,溶液温度20℃为宜。     

明胶溶液浓度对其发泡性能的影响

明胶具有发泡性能,该性能在食品、医药、洗涤、化妆品等行业具有很好的潜在应用价值。明胶浓度对其体系的发泡性能和发泡稳定性产生的影响,将直接影响到其产品的质量和性能。因此,本文采用搅拌法,在60℃水浴条件下,采用100mL明胶溶液,研究了明胶溶液浓度对其发泡性能和泡沫稳定性的影响。实验结果表明:在相同的温度和转速条件下,随着明胶溶液浓度的增加,其发泡量逐渐减少,而泡沫稳定性则越来越好。A型明胶溶液浓度为1%时发泡量最大,最大值为71mL;在浓度为9%时泡沫半衰期为86min,表现出较好的泡沫稳定性。B型明胶溶液浓度为1%时发泡量最大值为52mL;溶液浓度为9%时泡沫半衰期为3min。A型明胶和B型明胶两者相比,A型明胶具有更好的发泡性能及泡沫稳定性。     

Development of Urea Crosslinked Thin Film for Biomedical Application

Bioadhesive thin film was prepared from gelatin using urea as plasticizer as well as crosslinker. Viscosity of the solution showed a decreasing trend with increasing heating time. Nevertheless, viscosity and pH increased with increasing urea content and heating time to a certain level. Mechanical properties and fluid drainage capability of the films of blend solutions were also evaluated. Tensile strength showed a mixed behavior with urea content and heating but flexibility increased with urea content. Besides, crosslinked film showed no cytotoxic effect rather fluid absorption capability was improved. All of these results suggest its potentiality for effective wound dressing material.     

碳添加剂对聚丙烯腈溶液流变性影响的研究

以碳纳米管(MCNT)和碳黑(CB)为添加剂,采用溶液共混的方法,讨论了添加剂浓度、放置时间、温度、剪切速率对聚丙烯腈溶液的表观黏度及黏流活化能(ΔΕη)的影响。结果表明:随着MCNT含量的增加,聚丙烯腈溶液的黏度先增大后减小,添加1.0%MCNT时,聚丙烯腈溶液的黏度最大,活化能也同时达到最大;随着碳黑含量的增加,黏度与活化能都随之增加,但增加幅度不大。两种PAN溶液都属于明显的切力变稀的非牛顿流体,随着剪切速率的增加,黏度下降;但在高切变速率(>800s-1)时,黏度几乎不变。     

Optimization of coating solution viscosity of hollow fiber‐supported polydimethylsiloxane membrane for CO2/H2 separation

To optimize the CO₂ permeation and CO₂/H₂ separation performance of hollow fiber‐supported polydimethylsiloxane (PDMS) membranes, the effect of the viscosity of the PDMS coating solution on surface morphologies, thickness of PDMS layer, and solution intrusion into surface pores of hollow fiber supports was investigated. Increases in both stirring time and standing time could increase the viscosity of the PDMS solution. The PDMS layer thickness increased when the coating solution viscosity increased, whereas the surface roughness of the PDMS layer markedly decreased and then slightly changed. Moreover, when the stirring time of the PDMS coating solution was 9 min and the standing time was increased from 2 min to 25 min, the CO₂ permeance first decreased, then increased to ～2250 GPU probably due to the decreased intrusion depth, and finally decreased because of the substantially increased thickness of the PDMS layer. However, the CO₂/H₂ selectivity increased to 3.4 with an increase in coating solution viscosity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45765.     

表面活性剂对聚合物溶液流变性的影响

本文详细研究了表面活性剂对HPAM溶液流变性的影响。研究结果表明,HPAM溶液的粘度随OP-10加量的增加变化不明显,而其表观粘度都随SDBS的加入而持续降低,并且水解度越小,降低程度越明显。研究结果还表明,溶液粘度变化趋势与表面活性剂临界胶束浓度之间没有明显联系。     

假酸浆子胶质的乳化性评价

评价了假酸浆子胶质的乳化性。结果表明,假酸浆子胶质能降低油水界面张力;乳状液稳定性随胶质质量浓度增加而增强,加油量增多而下降。乳化温度和贮存温度越高,乳状液越不稳定。胶质溶液pH改变胶质溶液的黏度进而影响乳状液稳定性。pH=3时,胶质溶液乳化活性(emulsion ability,EA)和乳化稳定性(emulsionstability index,ESI)达最高值,分别为1.247和63.353 h。乳状液粒径随质量浓度和均质压力增大而减小。均质压力过大会导致乳状液放置后易聚集而不稳定,合适的均质压力为5 MPa。     

Gelatin renaturation and viscosity of dilute gelatin solutions

Mechanical melting temperatures of gelatin gels determined by the ball-drop method are decreased by several degrees if 0.5m potassium thiocyanate aqueous solution is used as solvent instead of pure water. In agreement with that, the growth with time of the viscosity of dilute gelatin solutions occurs at lower temperatures in 0.5m potassium thiocyanate. Surprisingly enough, the reduced specific viscosity after five hours at 5° C is lower in pure water. This is because the temperature dependence of this quantity in water is not monotonic, and the temperature 5° C is below that at which a distinct maximum is reached. No similar maximum has been reported so far for the temperature and time dependences of the extent of renaturation determined by optical techniques. The difference between the results of these two methods could be ascribed to the fact that the viscosity of solutions of partially renaturated gelatin is given not only by the fraction of monomer units in the helical conformation but also by the average length of created helices.