Photochemical anchoring of polyelectrolyte to the electrode surface using polymeric silane-coupling agents and their water durability

Abstract

This paper reports a simple effective way to photochemically attach a polyelectrolyte layer to an electrode substrate. The system is based on photoreactive benzophenone (BP)-containing copolymers that are bound to alumina surfaces via an alkoxysilane coupling reaction. The alumina substrate was then covered with a BP film that can be reacted with the polyelectrolyte by irradiation with UV light. As a result of the photochemical reaction, the polyelectrolyte was bound covalently to the electrode surfaces. As an example, a thin layer of copolymer of [2-(acryloyloxy)ethyl]trimethyl ammonium chloride (AETAC), styrene (ST), 2-hydroxyethylacrylate (HEA), and 4-acryloxybenzophenone (BPA) (AETAC/ST/HEA/BPA=60/33/4/3) was attached successfully. A pretreatment of the substrate with BP-containing polymeric silane-coupling reagents, AETAC/3-(trimethoxysilyl)propyl methacrylate (TMSPM)/HEA/BPA=50/30/10/10 or TMSPM/HEA/BPA=50/25/25, was performed to improve the water durability and stability at high temperatures and humidity. Their water durability, high temperature/humidity stabilities and long-term stability were evaluated to confirm their usefulness as a humidity-sensing polyelectrolyte membrane.

AC Complex Impedance Study on the Resistive Humidity Sensors with Ammonium Salt-Containing Polyelectrolyte using a Different Electrode Pattern

“…4,5,[9][10][11][12][13][14] The thickness of the polyelectrolyte closely affects the humidity sensitivities, such as hysteresis and response or recovery time. 15,16 In addition, IDEs-type humidity sensors exhibited a significant change in impedance with a change in the number of fingers and gap size between electrode fingers, which are related to the design of the electrode.…”

Preparation of Humidity Sensor Using Novel Photocurable Sulfonated Polyimide Polyelectrolyte and their Properties

“…감습성 단량체의 중합에 의해 제조된 습도센서용 전해질 고분자 감습막 필름은 물에 쉽게 용해되어 센서의 성능이 크 게 감소한다. 1 따라서 감습막 필름의 물에 대한 안정성과 내 구성을 향상시키기 위하여 소수성 단량체와 공중합, [2][3][4][5][6] 가교 화, [7][8][9][10][11][12] interpenetrating polymer network(IPN) 형성 [13][14][15] 및 유 기/무기 하이브리드 결합을 형성하는 방법 [16][17][18][19][20][21][22] 등이 있다. 그 중에 감습막의 가교는 습도센서 필름의 내수성과 안정성을 향상시키는 효과적인 방법으로 확인되었다.…”