Piezoelectric approaches to organic polymeric materials

Abstract

Piezoelectricity refers to the ability of certain materials to generate electric charges when subjected to mechanical stress or strain, and vice versa. This phenomenon has been widely studied in inorganic materials, such as quartz and ceramics, and has found numerous applications in sensing, actuation, and energy harvesting. There has been a growing interest in piezoelectricity for polymeric materials that are lightweight, flexible, and highly processable for a wide range of applications, including sensors for environmental and biomedical monitoring, energy conversion from mechanical vibrations, and actuation in soft robotics. Note that the characterization of the piezoelectric tendency of polymeric materials tends to be a complex and challenging process, as the effect is often weak and dependent upon various factors including material structure, processing conditions, and measurement setup. While many past and current review articles have covered theories and principles associated with piezoelectric polymers to some extent, detailed information on the corresponding experimental techniques used to measure their piezoelectric properties remains limited. This mini‐review paper aims to consolidate and summarize various approaches, including quasi‐static methods, optical interferometry, dielectric spectroscopy, and piezoelectric force microscopy, and provide insights into the principles, advantages, limitations, and challenges associated with these techniques.This article is protected by copyright. All rights reserved.

Superhydrophobic, Highly Adhesive, and Corrosion-Protective Fluoropolymer-Modified Polythiophene Coatings

“…The chemical composition of a surface also primarily influences its surface energy. ,, For instance, Zisman et al demonstrated that the surface energy decreases with increasing fluorine content in a polymer, following the sequence: CH 2 > CH 3 > CF 2 > CF 3 . , Fluoropolymers exemplify this principle such that the presence of highly polarized and inert C–F bonds promotes material stability and offers a multifaceted defense mechanism against environmental degradation. − This attribute renders them invaluable for designing insulating layers that promote ionic permeability and prevent electron transfer between the metal and corrosive medium, thereby averting the oxidation process. − Polyvinylidene fluoride (PVDF) and its CF 3 -containing copolymer, PVDF- co -hexafluoropropylene (PVDF–HFP), represent two exemplary fluoropolymers extensively employed in the coating manufacturing industry. Renowned for their exceptional inertness, these polymers offer remarkable corrosion and wear resistance, alongside mechanical integrity, film-forming characteristics, low surface energy, and thermal stability. , The synergy between PVDF’s durability and chemical resistance and HFP’s inclusion promoting ease of processability yields coatings that boast mechanical flexibility, outstanding protective properties, and lower surface energy. , Despite their inherently low surface energy, these fluoropolymers alone cannot achieve superhydrophobicity. , Customizing rough surfaces using materials with low surface energy or generating a rough surface on hydrophobic materials is typically employed to achieve superhydrophobicity.…”