U.S.-Mexico Collaborative Research: Characterization of Liquid Crystals and Colloidal Semiconductor Particles by Positron Annihilation

该奖项将支持雪城大学的一组研究人员在J.Fendler教授的指导下，与墨西哥墨西哥城国家调查研究所的一个类似小组在L.A.Fucuguchi教授的指导下开展合作研究。在过去的几年里，合作者们成功地从事了胶束、微乳液、液晶、囊泡和聚合囊泡的制备和表征。所有这些分子聚集体都有一个共同的主题，那就是它们模仿了生物膜的功能。在拟议的合作期间，研究人员打算利用核技术进行膜模拟的研究，长期目标是增加我们对生物膜化学的理解。合作者的工作一直以其生产力和互惠互利为特征。美国已经制备了囊泡和聚合囊泡，而墨西哥已经制备了微乳液和液晶并对其进行了表征。美国研究小组使用静态和动态光散射以及本征和外在光谱方法研究了聚集体的结构和形貌。另一方面，墨西哥小组使用偏振光学显微镜来表征液晶，并在使用正电子湮没技术确定不同系统中的相变方面经验丰富。这些技术的使用使研究人员能够检测到表面活性物质形态的细微而显著的变化。此外，拟议的研究在提高石油采收率、受控药物释放、催化和控制各种化学过程方面具有重要的应用潜力。

This award will support a group of researchers at Syracuse University under the direction of Prof. J. Fendler to carry out collaborative research with a similar group at the Instituto National de Investigaciones Nucleares in Mexico City, Mexico, under the direction of Prof L. A. Fucugauchi. Over the past several years the collaborators have been successfully engaged in the preparation and characterization of micelles, microemulsions, liquid crystals, vesicles and polymerized vesicles. All of these molecular aggregates have a common theme in that they mimic the functions of a biological membrane. For the proposed period of collaboration, the researchers intend to pursue the investigation of membrane mimetics using nuclear techniques with the long range goal of increasing our understanding of the chemistry of biological membranes. The collaborators' work has been characterized by its productivity, and mutual benefits. Vesicles and polymerized vesicles have been prepared in the United States while microemulsions and liquid crystals have been prepared and characterized in Mexico. The structures and morphologies of the aggregates have been investigated by the U.S. group using static and dynamic light scattering and intrinsic and extrinsic spectroscopic methods. The Mexican group, on the other hand, has used polarized light microscopy for the characterization of liquid crystals and is experienced in the use of positron annihilation techniques to determine phase changes in the different systems. The use of these techniques has allowed the investigators to detect subtle and significant changes in surfactant morphologies. Additionally, the proposed research has a significant potential for application to enhanced oil recovery, controlled drug release, catalysis, and the control of various chemical processes.