(174bb) Time-Dependent FTIR Microscopy for Mechanism Investigations and Kinetic Measurements in Interfacial Polymerisation: A Microporous Polymer Nanofilm Study

Time-Dependent FTIR Microscopy for Mechanism Investigations and Kinetic
Measurements in Interfacial Polymerisation: A Microporous Polymer Nanofilm Study

Dan Ren¹, Jet Ing Ngie
Yeo², Tian-Yin Liu^{1 ,2*} and Xiaolin
Wang^1*

¹Beijing
Key Laboratory of Membrane Materials and Engineering, Department of Chemical
Engineering, Tsinghua University, Beijing, China

²Barrer
Centre, Department of Chemical Engineering, Imperial College London, South
Kensington Campus, London, SW7 2AZ, UK

*email: *tianyin.liu@imperial.ac.uk *xl-wang@tsinghua.edu.cn

Interfacial polymerisation plays a pivotal role in chemical industry
and academic researches but acquiring chemical insights into the
formation of ultra-thin films remains challenging.^[1] A real-time
and in-situ characterisation
of the interfacial polymerization process is demonstrated here by using Fourier
Transform Infrared (FTIR)-mapping spectroscopy with microscopy. The entire
formation process of microporous polyarylate films
was studied using this approach to reveal the mechanism and measure reaction
kinetics, which are not established. Our key findings reveal that the mechanism
involves a two-stage reaction: the diffusion-controlled
stage and the film formed stage. We measured the diffusivity by 2D- DOSY of ¹H-NMR and the oil/water
partition
coefficient K by UV spectrum. The concentration changes of each species over
time is quantified based on areas of the identified FTIR peaks. The reaction rate
constant, k is obtained for resorcinol
(RES)-trimesoyl chloride (TMC) (119.0 L mol^-1
s^-1) and 9,9-bis(4-hydroxyphenyl)fluorene (BHPF)-TMC (32.87 L mol^-1
s^-1) ,which illustrated
that the
rigid and contorted monomer, BHPF, is slower in both diffusion and reaction
during film formation.

This work was
supported by National Key Technologies R&D Program
of China (No. 2015BAE06B00).

References

[1] A.
Nowbahar, V. Mansard, J. M. Mecca, M. Paul, T. Arrowood and T. M. Squires, J. Am. Chem. Soc., 2018, 140, 13083-13091.

[2] M. F. Jimenez-Solomon, Q. Song, K.
E. Jelfs, M. Munoz-Ibanez and A. G. Livingston, Nat. Mater., 2016, 15,
760-769.

Keywords: Fourier Transform Infrared (FTIR)-mapping
spectroscopy; interfacial polymerization;
polyarylate; kinetics.