RUI: Determination of the Free-Volume Size Distributions in Polymeric Materials

一种新的正电子湮没谱学方法 寿命技术将用于确定自由体积 聚合物材料中的孔尺寸分布。 研究 活动包括：1）正电子寿命测量， 温度和压力在环氧树脂、聚乙烯 醋酸酯），PMMA和PEEK聚合物，以及2） 正电子寿命谱学通过显著改进核 计数效率和仪器分辨率，并通过采用 数值拉普拉斯反演技术来分析正电子 寿命数据。 这些中的自由体积孔尺寸分布 选择的聚合物将通过实验确定， 第一次作为研究的一部分。

A new spectroscopic approach using the positron annihilation lifetime technique will be used to determine the free-volume hole-size distributions in polymeric materials. The research activities involve: 1) positron lifetime measurements as a function of temperature and pressure in epoxy, poly(vinyl acetate), PMMA and PEEK polymers, and 2) a renaissance of positron lifetime spectroscopy by significantly improving nuclear counting efficiency and instrument resolution, and by employing numerical Laplace inversion techniques to analyze the positron lifetime data. The free-volume hole-size distributions in these selected polymers are to be determined experimentally for the first time as a part of the research.