Tunable mesoporous silica films were prepared though a sol-gel process directed by the self-assembly of various triblock copolymers. Positron annihilation γ-ray energy spectroscopy and positron annihilation lifetime spectroscopy (PALS) based on intense pulsed slow positron beams as well as ellipsometric porosimetry (EP) combined with heptane adsorption were utilized to characterize the open porosity/interconnectivity and pore size distribution for the prepared films. The consistency between the open porosities was examined by the variations of orthopositronium (o-Ps) 3γ annihilation fractions and the total adsorbed volumes of heptane. The average pore sizes deduced by PALS from the longest-lived o-Ps lifetimes are in good agreement with those by EP on the basis of the Barrett–Joyner–Halenda model, as indicated by a well fitted line of slope k = 1. The results indicate that the EP combined with heptane adsorption is a useful method with high sensitivity for calibrating the mesopore size in highly interconnected mesoporous films, whereas PALS is a novel, complementary tool for characterizing both closed and open pores in them.

中文翻译：

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正电子湮没寿命光谱法和椭偏孔隙率测定法研究介孔二氧化硅薄膜的开孔率和孔径分布

通过由各种三嵌段共聚物的自组装指导的溶胶-凝胶工艺制备了可调介孔二氧化硅薄膜。基于强脉冲慢正电子束的正电子湮没 γ 射线能谱和正电子湮没寿命谱 (PALS) 以及椭圆孔率 (EP) 结合庚烷吸附来表征制备的开孔率/互连性和孔径分布电影。开放孔隙率之间的一致性通过正电子 (o-Ps) 3γ 湮没分数和庚烷总吸附体积的变化来检查。PALS 从最长寿命的 o-Ps 寿命推导出的平均孔径与基于 Barrett-Joyner-Halenda 模型的 EP 一致，如拟合良好的斜率线所示k = 1。结果表明，EP 结合庚烷吸附是一种有用的方法，具有高灵敏度，可用于校准高度互连的介孔膜中的介孔尺寸，而 PALS 是一种新颖的互补工具，用于表征其中的闭孔和开孔。