Enhancement of facilitated olefin transport by amino acid in silver–polymer complex membranes

Silver ions dissolved in a polymer matrix are additionally coordinated by carbonyl oxygens of asparagines and their counter anions interact with cationic sites, resulting in the enhanced activity of the silver ion as an olefin carrier for facilitated olefin transport.The authors acknowledge the financial support from the Ministry of Science and Technology of Korea through the Creative Research Initiatives Program. Sang Wook Kang and Kookheon Char also acknowledge the financial support from the National Research Laboratory Program (Grant M1- 0104-00-0191) and the Ministry of Education through the Brain Korea 21 Program of Seoul National University

올레핀 촉진수송 분리막의 성능향상을 위한 Valine의 효과

A remarkable seperation performance of olefin/paraffin mixtures has been observed through facilitated olefin transport membranes consisting of silver ions dissolved in polymer matrices. In this research, valine, an amino acid, was introduced in poly (2-ethyl-2-oxazoline)(POZ)/AgBF4 membranes to increase the separation performance. FT-IR spectra show that the cationic sites(-NH3+) of valine interact with the counter anion of the silver salt, resulting in the enhanced activity of the silver ions and consequently improved separation performance. Therefore, the POZ/AgBF4 membranes containing valines exhibit the higher permeance as well as the higher selectivity of propylene/propane than those without valine. ; 은염이 함유된 고분자 전해질을 이용한 올리핀 촉진수송 분리막의 고체상에서 높은 올레핀/파라핀 분리 성능을 나타내었다. 본 연구에서는 프로필렌/프로판 분리 선택도와 투과도의 성능을 향상시키기 위해 아미노산의 일종인 valine을 고분자 전해질막에 첨가하였다. FT-IR 분광학을 통해 valine의 양이온과 은염의 음이온이 상호작용을 하고, 그 결과 valine은 은이온의 활성도를 증가시킴을 알 수 있었다. 따라서 valine을 포함하고 있는 촉진수송 분리막은 valine이 없을 때보다 더 높은 선택도와 투과도를 나타내었다.This research was supported by the Mionistry of Science and Technology of Korea through the Creative Research Initiatives Program (YSK), the CO2 Reduction & Sequestration Center (M102KP01000102K160102011)(JW), the National Research Laboratory Program (Grant M1-0104-00-0191) and the Ministry of Education through the Brain Korea 21 Program of Seoul National University(KC)

Effect of amino acids in polymer/silver salt complex membranes on facilitated olefin transport

The effect of amino acids such as asparagine, valine, glutamic acid and glycine on silver ion activity as a olefin carrier in membrane consisting of silver ions dissolved in poly(2-ethyl-2-oxazoline) (POZ) has been investigated. The presence of amino acids leads to the weakened interaction of the silver ion with its counteranion resulting from the electrostatic interaction between counteranion and NH3+ of amino acids, as confirmed by FT-IR spectra. As a result, the mixed gas permeances and selectivities of propylene/propane through POZ/AgBF4 or POZ/AgNO3 membranes intriguingly increased upon addition of the amino acids. However, the improvement of separation performance is strongly dependent on the type and the concentration of amino acids. Among the amino acids tested, the presence of asparagine containing amide group was found to improve the separation performance of the membranes most significantly. On the other hand, the performance of membrane with lysine containing amine group was the lowest, indicating the amine is not the effective ligand for silver ion in facilitated olefin transport membranes.The authors acknowledge the financial support from the Ministry of Science and Technology of Korea through the Creative Research Initiatives Program. Kookheon Char also acknowledges the financial support from the National Research Laboratory Program (Grant M1-0104-00-0191) and the Ministry of Education through the Brain Korea 21 Program of Seoul National University

Nanocomposite Silver Polymer Electrolytes as Facilitated Olefin Transport Membranes

Solid-state silver polymer electrolyte membranes containing AgNO3 dissolved in poly(2-ethyl-2-oxazoline) (POZ) as an olefin carrier are not efficient for the separation of olefin/paraffin mixtures (selectivity 1). The addition of fumed silica nanoparticles into the POZ/AgNO3 complex membranes, however, resulted in a surprisingly significant enhancement of the permeance and selectivity (higher than 80) for propylene/propane mixtures. These enhancements are explained in terms of the silver ion activity in olefin coordination. FT-IR, X-ray photoelectron spectroscopy (XPS) and FT-Raman demonstrate that the silver ion activity continuously increases by Lewis acid–base interactions upon incorporation of the silica nanoparticles up to 0.1 mole ratio of silica, above which it abruptly decreases. Furthermore, the structural change of polymer electrolyte membranes took place by the presence of nanoparticles, supported by the Tg measurement.We acknowledge the partial financial support from Hanyang University through an internal research fund. KC acknowledges the financial support of the National Research Laboratory Program (Grant M1-0104-00-0191) and the Ministry of Education through the Brain Korea 21 Program at Seoul National University