The Behavior of Amphiphile at Oil-Water Interface by Monte Carlo Simulation

A novel simple two-dimensional square-lattice model of amphiphile at oil-water interface is developed,in which oil and water act as solvent and occupy empty sites and amphiphile occupies chains of sites. In this model, the oil-water interface is fixed, And amphiphile molecules will be enriched at the oil-water interface. The interfacial concentration of amphiphile calculated by Monte Carlo method shows that it is easier for the hydrophilic-hydrophobic balanced amphiphile to stay at the interface. And the adsorption of amphiphile increases with the increase of amphiphile concentration and the decrease with temperature.

Synergistic Effect of Amphiphiles at Oil-Water Interface: By Monte Carlo Simulation

Amphiphile-oil-water system is complicated. The real behavior of amphiphile in the interface is still undnown despite that this behavior is very important in determining the stability of emulsion system. In this paper, the interface properties of amphiphile at oil-water interface were investigated by a square-lattice model Monte Carlo simulation method. The synergistic effect was found for hydrophobic and hydrophilic amphiphile mixture systems; and the synergistic effect disappears or was weakened as the amphiphile at the interface region became dilute with the increasing of temperature.

Synthesis of Amphiphilic Starch Derivatives Using One-pot Synthesis Procedure

Amphiphilic starch derivatives with high content of functional groups were prepared from potato starch using a one-pot synthesis method with a single reaction medium for the entire procedure. Potato starch was benzylated, followed by the introduction of hydroxypropyltrimethylammonium(HPMA) moieties without the purification of intermediates. The synthesis was performed under heterogeneous conditions, leading to the formation of benzyl 2-hydroxypropyltri methylammonium starch chloride(BnHPMAS) with a total degree of substitution(DS) of up to 1.4. This process improved the efficiency of the preparation of amphiphilic starch derivatives and reduced the time and resources consumed by avoiding a separation process and purification of the intermediate compounds.The DS of BnHPMAS was in the range of 0.36 to 1.4, which could be tuned by varying the molar ratio of the reagents to repeating unit or by changing the reaction temperature, time, and medium. The structure of the amphiphilic starches was characterized using elemental analysis, size exclusion chromatography,fourier transform infrared spectroscopy(FT-IR), and nuclear magnetic resonance(NMR) spectroscopy. Moreover, the surface tension and turbidity of the solutions of the products were measured for their potential application in the removal of dissolved and colloidal substances in paper cycling water.

两亲性木薯淀粉的性质与洗涤应用研究

以木薯淀粉为原料、十二烯基琥珀酸酐为改性剂,制备了两亲性木薯淀粉(ACS)。利用FT-IR、XRD、SEM表征了ACS的结构。通过表面张力探讨ACS在不同温度、不同盐环境及其与LAS、SDS、BS-12复配的表面活性;研究了ACS乳化性能和洗涤应用。结果表明,ACS的表面活性随温度升高而增大;无机盐提高ACS表面活性的能力大小依次为:MgCl_(2)、NaCl、KCl、CaCl_(2),MgCl_(2)降低表面张力高达25.7%;LAS、SDS、BS-12与ACS复配具有协同增效提高表面活性的作用,增效能力大小依次为:BS-12、SDS、LAS。ACS具有优良的表面活性和洗涤性能,与LAS、SDS协同洗涤效应显著。

两亲性淀粉自组装研究进展

两亲性淀粉具有独特的结构特征,将其溶于选择性溶剂中,在疏水力的推动下会自组装形成核-壳结构的球形胶束。胶束可包合疏水性客体,对客体进行空间束缚,形成超分子包合物。两亲性淀粉自组装扩大了淀粉作为载体的应用范围。总结了两亲性淀粉自组装的原理、制备方法、影响因素,介绍了该方法应用于食品、医药、工业领域的研究进展,并提出了目前两亲性淀粉自组装研究领域存在的问题以及今后可能的研究方向。

双亲性淀粉的制备与封堵特性研究

以羧甲基淀粉为原料，苯甲酰氯为疏水试剂进行疏水化改性制各双亲性淀粉。研究了反应温度、反应时间、疏水试剂用量和碱用量对双亲性淀粉疏水取代度的影响。得到优化条件为：反应温度35℃，反应时间60min，nf苯甲酰氯）／n（羧甲基淀粉）=2．5，n（氢氧化钠）／n（苯甲酰氯）=1．0，双亲性淀粉疏水取代度可达0．8522。调节反应条件，可控制疏水取代度为0．1～0．9。红外光谱分析验证疏水基团接枝到羧甲基淀粉分子上，扫描电镜表明在改性淀粉的表面形貌发生了变化。羧甲基淀粉经疏水化改性后，溶解性良好而又具有一定的疏水性。该双亲性淀粉钻井液体系应用于油气田储层封堵保护，渗透率恢复值大于90％，储层保护效果显著。

辛烯基琥珀酸酯-羧甲基淀粉膜力学性能的研究

以玉米淀粉、一氯乙酸及辛烯基琥珀酸酐为原料,通过2步反应制备了辛烯基琥珀酸酯-羧甲基油水两亲性淀粉(OS-CMS)。采用红外光谱进行结构表征;用X射线衍射仪进行薄膜结晶度测试。通过力学性能测试,研究了在不同油水官能团摩尔比及变性程度对OS-CMS薄膜力学性能的影响。结果表明,经变性后的OS-CMS薄膜结晶度降低;随着摩尔比的提高,OS-CMS薄膜的断裂强度有所上升,断裂伸长率先上升后下降,最终提高了薄膜的韧性,在2种官能团摩尔比为1∶1时,薄膜的断裂伸长率最大;随着变性程度的提高,OS-CMS薄膜的断裂强度与断裂伸长率也逐渐增加,进一步改善了力学性能。

季铵醚化-辛烯基琥珀酸酯化淀粉浆料的稳定性及生物降解性

为了改善淀粉浆料的使用效果,以3-氯-2-羟丙基三甲基氯化铵为醚化剂、辛烯基琥珀酸酐为酯化剂制备了一系列两亲性淀粉浆料(QAS)。利用红外光谱对QAS进行表征分析,探讨了亲/疏水基团取代度之比、总取代度对QAS浆液黏度热稳定性和生物降解性的影响,评价了QAS与常用浆纱助剂的相容性。结果表明,QAS浆液的黏度波动率不超过15%,温度对其浆液的黏度热稳定性影响不大,QAS与常用浆纱助剂有较好的相容性,有良好的浆纱应用前景。随着阳离子基团取代度和总取代度的增大,QAS浆液的生物降解性有所降低,QAS总取代度低于0.05为宜。

双亲性淀粉浆料的研究进展

为提高淀粉的上浆性能,分析了对淀粉进行双亲性变性处理的意义,总结了双亲性淀粉浆料,包括阴阳离子型双亲性淀粉浆料、亲疏水型双亲性淀粉浆料,在纺织经纱上浆中应用的研究现状,论述了双亲性变性对淀粉浆料黏附性和浆膜力学性能的作用效果,并对今后双亲性淀粉浆料的研究方向进行了预测。认为亲疏水型接枝改性淀粉浆料品种及适宜于具体经纱品种的双亲性淀粉浆料品种,以及可降低均聚物产生、可控接枝支链长度的淀粉接枝改性方法将是今后双亲性淀粉浆料的重要研究方向。

双亲两嵌段接枝淀粉浆料的制备及其上浆性能

为提高淀粉浆料的使用性能,为纺织经纱上浆提供新型接枝淀粉浆料品种,以丙烯酸(AA)和丙烯酸丁酯(BA)为接枝单体,2-溴异丁酯化淀粉(BBES)为大分子引发剂,利用电子转移活化再生催化剂原子转移自由基聚合技术成功制备了双亲两嵌段接枝淀粉[BBES-g-(PAA-b-PBA)]。以酸解淀粉、BBES为对比样,探讨了双亲两嵌段接枝支链的引入对淀粉浆液性能、浆膜力学性能的影响。结果表明:接枝支链的引入能够进一步增加淀粉浆液的黏度热稳定性、黏附性及其浆膜的断裂伸长率;随着AA接枝率的降低及同时BA接枝率的增加,淀粉浆液的黏度热稳定性变化不大,对涤纶的黏附力和浆膜的断裂伸长率逐渐增加,浆膜的断裂强度逐渐降低。

辛烯基琥珀酸酯-羧甲基淀粉/PVA共混浆料的性能研究

为了改善淀粉的性能,采用了辛烯基琥珀酸酯-羧甲基油水两亲性淀粉,并将其与PVA进行物理共混,研究了PVA聚合度、醇解度以及共混比对纤维粘附性能、浆膜力学性能的影响。结果表明,提高PVA聚合度与醇解度可改善对纯棉和涤纶的粘合强度,并显著提高共混浆膜的断裂伸长率与断裂强度,其中,PVA1799与OS-CMS共混浆料的性能表现最优异;在OS-CMS加入PVA后,共混浆膜的结晶度下降且随着共混浆料中PVA共混比的提高,浆料的粘合强度与浆膜的力学性能随之提高。