Tuning the Permeation Properties of Poly(1‐trimethylsilyl‐1‐propyne) by Vapor Phase Infiltration Using Trimethylaluminum

• DOI: 10.1002/admi.202400171
• Publication Date: 2024-08-14T06:52:25Z
• Authors: Jonathan Jenderny; Nils Boysen; Jens Rubner; Frederik Zysk; Florian Preischel; Teresa de los Arcos; Varun Raj Damerla; Aleksander Kostka; Jonas Franke; Rainer Dahlmann; Thomas D. Kühne; Matthias Wessling; Peter Awakowicz; Anjana Devi
• Keywords: Technology; PTMSP; ddc:540; Physics; QC1-999; T; 02 engineering and technology; TMA; vapor phase infiltration; gas separation; 0210 nano-technology; membrane

AbstractVapor phase infiltration (VPI) has emerged as a promising tool for fabrication of novel hybrid materials. In the field of polymeric gas separation membranes, a beneficial impact on stability and membrane performance is known for several polymers with differing functional groups. This study for the first time investigates VPI of trimethylaluminum (TMA) into poly(1‐trimethylsilyl‐1‐propyne) (PTMSP), featuring a carbon–carbon double bond as functional group. Saturation of the precursor inside the polymer is already attained after 60 s infiltration time leading to significant densification of the material. Depth profiling proves accumulation of aluminum in the polymer itself, but a significantly increased accumulation is visible in the gradient layer between polymer and SiO2 substrate. A reaction pathway is proposed and supplemented by density‐functional theory (DFT) calculations. Infrared spectra derived from both experiments and simulation support the presented reaction pathway. In terms of permeance, a favorable impact on selectivity is observed for infiltration times up to 1 s. Longer infiltration times yield greatly reduced permeance values close or even below the detection limit of the measurement device. The present results of this study set a strong basis for the application of VPI on polymers for gas‐barrier and membrane applications in the future.