다양한 PVP 분자량에 따른 은 나노 입자의 형성과 올레핀 촉진 수송 응용

Abstract

올레핀 촉진 수송 분리막에 많이 쓰이고 있는 운반체 소재 중 하나인 은 나노 입자를 분자량이 다른 poly(N-vinyl pyrrolidone) (PVP)를 환원 및 안정제로 사용하여 합성하고, 은 나노 입자의 형성과 크기들을 분석하였으며, 이들을 다시 메트릭스로서의 PVP에 분산시켜 분리막으로 응용될 때 PVP 분자량의 영향에 대하여 연구하였다.

제 1장에서는 현재 석유 화학 산업에서 올레핀/파라핀의 분리의 중요성과 현재 가지고 있는 문제점에 대해서 설명하고 분리막의 개념과 장점을 통해 대체 분리 기술로서의 전망에 대해 소개한다. 또 한, 프로필렌/프로판을 분리 하는 데에 있어서 분리막 기술이 갖는 한계를 제시한다. 이 한계점을 극복 하기 위한 하나의 방편으로 촉진수송의 개념이 소개 되고 있으며 그 개발 역사와 해석 모델을 제공함으로써 앞으로 설명될 수행된 연구에 대한 이론적 배경을 제공한다.

제 2장에서는 은 이온과 은 나노 입자를 운반체로 이용하여 성공적으로 올레핀 촉진 수송에 이용한 사례를 들어 설명하고 특히 최근 은 나노 입자의 합성과 전자 수용체를 도입함으로써 올레핀 촉진 수송을 성공적으로 수행한 연구를 소개한다. 이 연구를 바탕으로 poly(N-vinyl pyrrolidone)의 분자량을 조절함으로써 은 나노 입자의 형성과 크기 변화 및 분포도를 주사전자현미경 (transmission electron microscopy)과 자외선-가시광선 분광기 (ultraviolet-visible spectroscopy)를 통해 확인하고 프로필렌/프로판 분리막으로 제조함으로 그 분리 성능을 측정하였다. 높은 분자량을 가진 고분자의 경우 그렇지 않은 경우보다 매트릭스로 활용 될 때에 그 안정성이나 내구성에서 더 좋은 성능을 보여 줌을 확인 할 수 있었다.| Formation of silver nanoparticles which were used as carriers for facilitated olefin transport was investigated by varying molecular weight of poly(vinyl pyrrolidone) (PVP) as both reducing and stabilizing agents. Additionally, the matrix property of PVP was also studied depending on the molecular weight of PVP.

In Part 1, the importance is issued on the separation of olefin/paraffin mixtures in the petrochemical industries, and the pros and cons of membrane process were discussed, compared to conventional cryogenic distillation. The facilitated transport concept was adopted to overcome the limitation of common polymeric membrane materials having low separation performance for olefin/paraffin mixtures. The phenomenological models for facilitated transport in the solid state membrane along with experimental backgrounds were also introduced briefly.

In Part 2, facilitated olefin transport membranes using silver ions or metallic silver nanoparticles as carriers were introduced. In particular, silver nanoparticles were synthesized with PVP as reducing and stabilizing agents, and subsequently polarized by 7,7,8,8-tetracyanoquinodimethane (TCNQ). The formation of silver nanoparticles was characterized by transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy by varying the molecular weight of PVP. Finally, membranes were made by dispersing the polarized silver nanoparticles in PVP as a polymeric matrix and the propylene/propane separation performance was investigated. In the viewpoint of long-term stability, the higher MW PVP was better than the low MW PVPs. It was therefore suggested that the high MW PVP could be more appropriate for reducing, stabilizing agents for formation of silver nanoparticles and matrix for facilitated olefin transport.; Formation of silver nanoparticles which were used as carriers for facilitated olefin transport was investigated by varying molecular weight of poly(vinyl pyrrolidone) (PVP) as both reducing and stabilizing agents. Additionally, the matrix property of PVP was also studied depending on the molecular weight of PVP.

In Part 1, the importance is issued on the separation of olefin/paraffin mixtures in the petrochemical industries, and the pros and cons of membrane process were discussed, compared to conventional cryogenic distillation. The facilitated transport concept was adopted to overcome the limitation of common polymeric membrane materials having low separation performance for olefin/paraffin mixtures. The phenomenological models for facilitated transport in the solid state membrane along with experimental backgrounds were also introduced briefly.

In Part 2, facilitated olefin transport membranes using silver ions or metallic silver nanoparticles as carriers were introduced. In particular, silver nanoparticles were synthesized with PVP as reducing and stabilizing agents, and subsequently polarized by 7,7,8,8-tetracyanoquinodimethane (TCNQ). The formation of silver nanoparticles was characterized by transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy by varying the molecular weight of PVP. Finally, membranes were made by dispersing the polarized silver nanoparticles in PVP as a polymeric matrix and the propylene/propane separation performance was investigated. In the viewpoint of long-term stability, the higher MW PVP was better than the low MW PVPs. It was therefore suggested that the high MW PVP could be more appropriate for reducing, stabilizing agents for formation of silver nanoparticles and matrix for facilitated olefin transport.