Synthesis and characterization of hydrogen bonded co-crystals for application asorganic ferroelectrics

• Main Author: Dharmavarapu Nikhil Rao
• Other Authors: Chen Lang
• Format: Theses and Dissertations
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/52918
• Institution: Nanyang Technological University

Ferroelectrics are a class of functional materials that display the property of possessing two or more distinct states of electrical polarization, which are switchable by the application of an external electric field. Among these materials, Organic Ferroelectrics has recently become a growing field of research.1In the recent past, low cost Organic Electronic Devices (OED) havegenerated significant interest for applications in sustainable energy, electro-optical devices, memory storage and so on. Organic devices offer advantages of ease of fabrication, light weight, lower cost, as compared to the conventional ferroelectric materials.The formation of molecular co-crystals based on principles of supramolecular chemistry i.e.linking molecules through secondary bonding such as the Hydrogen Bond, offers a novel design approach.This type of design also offers a flexibility of working with molecules which are not asymmetric (like conventional perovskites), but may display ferroelectric properties due to phenomena such as proton transfer in the hydrogen bond. Till date, very few materials systems have been developed which exhibit the ferroelectric behavior on account of hydrogen bond.2 The number of materials and understanding of such materials is limited in the literature and correlation between the hydrogen bond and ferroelectricity is not well understood. This work reports the successful synthesis of novel molecular co-crystals which could be potentially useful in organic ferroelectric development. New molecular co-crystals were synthesized starting from a low molecular weight organic Acid-Base combination and were studied using the characterization techniques of XRD, NMR, TGA, DSC, UV-VIS. An estimation of dielectric properties was attempted at room and low temperature.