Surface thermodynamics and adsorption kinetics: surface tension and its associated properties

小分子、表面活性剂、多肽和聚合物的表面热力学和吸附动力学在各种化学和生物医学工程系统中具有重要意义。表面热力学的一个核心性质是表面张力。从表面张力的行为可以推断出表面化学成分和分子吸附的变化。在未来五年，我们将重点研究选定的化学体系的表面张力及其相关性质，具体目标有四： 1.挥发性两亲小分子在水溶液和非水溶液中的表面张力。我们将产生各种条件下表面张力的实验数据和理论理解。这一系列研究的结果将对我们对表面和新兴纳米技术进步的理解产生重大影响。 2.与地外环境有关的条件下水-气混合物的表面张力。我们建议在不同的温度和压力下测量被蒸气二氧化碳(火星大气的主要成分)包围的水的表面张力。我们将把二氧化碳的蒸汽压与水的表面张力联系起来，为预测火星介孔土壤中的水分含量提供数据。 3.水溶液中自组装肽的表面张力及其相关性质。我们将利用我们在表面张力方面的专业知识，提取有关新设计的氨基酸配对多肽组装的实验条件的重要信息。这一成果将为纳米生物技术应用，特别是药物和基因输送提供控制多肽纳米结构的手段。 4.聚合物加工条件下超临界流体中聚合物熔体的表面张力。我们将测量有无介孔粒子的聚合物熔体在高压和高温下的表面张力。结果将用基于自洽场理论的理论模型来解释。这一成果将直接应用于塑料的微/纳米发泡。

Surface thermodynamics and adsorption kinetics of small molecules, surfactants, peptides, and polymers are of fundamental importance in various chemical and biomedical engineering systems. A central property in surface thermodynamics is surface tension. From the behavior of surface tension, one can infer changes in surface chemical composition as well as molecular adsorption. In the next five years, we will focus our studies on the surface tension and its associated properties of select chemical systems, with four specific objectives: 1. Surface tension of small, volatile, amphiphilic molecules in aqueous and non-aqueous solutions. We will generate both experimental data and theoretical understanding of the surface tension under various conditions. The outcome of this line of research will have significant impact on our understanding of surfaces and emerging nanotechnology advances. 2. Surface tension of water-gas mixtures under conditions relevant to extra-terrestrial environments. We propose to measure the surface tension of water surrounded with vaporous CO2 (the main component of the Martian atmosphere) at varied temperatures and pressures. We will correlate the vapor pressure of CO2 with the water surface tension, providing data to predications of water content in the mesoporous soils of Mars. 3. Surface tension and associated properties of self/co-assembling peptides in aqueous solution. We will exploit our expertise in surface tension and extract important information about experimental conditions under which the newly designed amino acid pairing peptides assemble. The outcome will provide means to control peptide nanostructures for nano-biotechnology applications, especially for drug and gene delivery. 4. Surface tension of polymer melts in supercritical fluids under polymer processing conditions. We will measure the surface tension of polymer melts under high pressure and temperature, with/without mesoporous particles. The results will be explained by theoretical modeling based on self-consistent field theory. The outcome will have direct application to micro/nanocellular foaming of plastics.