Designing of Self-healable and Self-assembled polymers towards self-stratifying coatings, strain sensing, and adhesive applications

Abstract

Self-stratifying coatings with self-healing capabilities are an advanced class of materials that improve surface durability and functioning. Self-stratifying coatings are designed to produce distinct layers upon application, each with unique qualities that address various functional requirements. This stratification is often caused by variances in the physical and chemical characteristics of the components in the coating composition. These coatings typically have three layers: top, middle, and bottom. However, self-healing coatings may fix damage on their own, increasing the coating's lifespan and performance. Combining self-stratification with self-healing capabilities entails creating a coating that can layer itself during application and repair itself if damaged. This necessitates a synergistic design in which each layer contributes to the overall self-healing capabilities while retaining its own features. Each layer can be equipped with unique self-healing processes. For example, the top layer may have UV-resistant, self-healing polymers, while the bottom layer could have microencapsulated corrosion inhibitors. The self-healing components must be stratification-compatible, so that they migrate to the appropriate layer during application. Such coatings are extremely beneficial in industries that require long-term dependability and durability, such as automotive, aerospace, electronics, and infrastructure. Self-stratifying coatings with selfhealing capabilities provide a smart approach for improving surface durability and usefulness. These coatings can greatly increase the service life of covered substrates and minimize maintenance costs by carefully designing their materials and including innovative healing processes. Furthermore, strain sensors with self-healing properties are sophisticated devices designed to detect mechanical deformations (such as stretching, compressing, and twisting) and repair themselves autonomously after being damaged. These sensors are crucial for structural health monitoring, wearable electronics, soft robotics, and a variety of other industries that require durability and dependability. Strain sensors with self-healing characteristics represent a significant improvement in sensor technology, providing increased durability and dependability for a wide range of important applications. Ongoing research strives to enhance the materials and systems involved in these sensors' performance and practical application. Furthermore, self-assembly of inorganic-organic hybrids, particularly those combining polyoxometalates (POMs) and polymers, is a promising area of materials research. These hybrid materials combine the distinct features of inorganic POM clusters with the adaptability of organic polymers, resulting in several applications in catalysis, energy storage, and nanotechnology. POM-polymer hybrids can self-assemble by a variety of interactions and mechanisms, including hydrogen bonding, electrostatic interactions, covalent and coordinate bonds, hydrophobic interactions, and so on. Self-assembly of inorganic-organic hybrids of polyoxometalates and polymers results in multifunctional materials with improved and controllable characteristics. These hybrids show promise for a variety of sophisticated applications, including catalysis, energy storage, drug delivery, and sensing. The ongoing study focuses on understanding and directing self-assembly processes to customize the characteristics of these hybrid materials to specific applications. This doctorate thesis aims to create self-stratifying polymers with self-healing characteristics for coating purposes. Self-assembly with increasing multifunctional physical and mechanical features. The thesis is structured into six chapters that focus on the scope and use of selfhealing and self-assembly polymers with specialized functionality for a variety of applications. Chapter 1. Introduction This chapter describes the backdrop and inspiration for the thesis. This chapter provides a review of self-stratifying, self-healing, and strain-sensing polymeric systems, including their physical and mechanical characteristics. In this section, we will go over the core concept and technique of the self-stratification coating, which has good mechanical qualities. Also mentioned are self-healing functional groups, which extend the self-life of the material. Furthermore, a detailed discussion of self-healable ion gels and their applications in gauge strain sensors is provided, as well as a measurement of strain sensor sensitivity. Furthermore, addresses the self-assembly of organic-inorganic hybrids and their applications in underwater adhesives. This chapter discusses the design opportunities for self-healing polymers in a variety of applications, as well as the strong physical and mechanical qualities, as well as the quick, efficient, multiple-time self-healing achieved by including numerous chemical functions. Chapter 2. Siloxane and Fluorous polymers for self-stratified Coating with Multiresponsive Self-Healing Properties This chapter discussed the use of the self-stratification idea in coating due to the incompatible behavior of two separate functional groups. In this case, siloxane and fluorous polymers are incompatible and organize themselves in layers. Thiol and cinnamyl groups were inserted as healing agents to extend the self-life of the material. The study also examined the selfstratification, thermal stability, tensile characteristics, phase transition, surface hydrophobicity, nano dynamic mechanical properties, and self-healing capability of crosslinked copolymers. Chapter 3a. PVA-Tannic acid and oligosiloxane-based self-stratified coating with self-healing properties XIX This chapter examined the usage of self-stratification in the coating due to the diffusion of the particles in two different layers in a mixture of solvents. PVA, TA (tannic acid), and oligosiloxanes self-assemble into large and small particles. Smaller particles, due to their increased mobility, are more likely to reach and aggregate at the top of the drying layer, whereas larger particles, with slower diffusion, trail behind and tend to remain deeper and arrange into a self-stratification layer. This material has high chemical and mechanical strength, as demonstrated by numerous characterizations. Chapter 3b. Poly(vinylalcohol)-Oligosiloxanes-Borate based hybrid polymer for self-healing applications In this chapter describes the explores boric acid-based self-healing in siloxane and PVA hybrid networks. We synthesize tricoordinated borate-based self-healing polymers. Siloxane, PVA, and boric acid formed the double network structure; boric acid links with both siloxane and PVA. This hybrid material self-heals for 4 minutes in the presence of water at 40 °C. This hybrid has mechanical strength measured by universal tensile testing (UTM) as well as thermal stability, phase transition, and surface properties examined. Chapter 4. PVIM-PPA based self-healed ionogel with superior toughness and strain-sensing applications This chapter described the self-healing ionogels for strain-sensing applications. In this work, we sought to build an ionogel made of poly(vinyl imidazolium) [PVIMH]n+ and polyphosphate anion [PPA]n-, with electrostatic interactions and hydrogen bonding to self-heal the material. The presence of phosphate anion has flame retardant properties, as proved experimentally by UL-94 and synthesized ionogel has been successfully employed as a strain-sensor to detect diverse human activities as a wearable device. Chapter 5. POM-Polymer hybrid fabricated into a rope-like structure and utilized in underwater applications In this chapter, describes the self-assembly of the polyoxometalates (POM) and polymerbased hybrid (PEI-hexyl-Br) [Co-WCo3] were assembled in a rope-like structure in methanol solvent, which provided underwater adhesive characteristics owing to the existence of electrostatic interactions and hydrogen bonding. Initially, self-assembly was analysed by the DLS and zeta potential and further examined by the FESEM and cryo-TEM. Chapter 6. Summary and Future Aspects This chapter focuses on the results of this thesis as well as potential future prospects in the connected topic.