Ambient temperature cross-linkable acrylic latexes: effect of cross-link density, glass transition temperature and application temperature difference on mechanical properties

Polymer Colloids: Current Challenges, Emerging Applications, and New Developments

Polymer colloids are complex materials that have the potential to be used in a vast array of applications. One of the main reasons for their continued growth in commercial use is the water-based emulsion polymerization process through which they are generally synthesized. This technique is not only highly efficient from an industrial point of view but also extremely versatile and permits the large-scale production of colloidal particles with controllable properties. In this perspective, we seek to highlight the central challenges in the synthesis and use of polymer colloids, with respect to both existing and emerging applications. We first address the challenges in the current production and application of polymer colloids, with a particular focus on the transition toward sustainable feedstocks and reduced environmental impact in their primary commercial applications. Later, we highlight the features that allow novel polymer colloids to be designed and applied in emerging application areas. Finally, we present recent approaches that have used the unique colloidal nature in unconventional processing techniques.

Drying rate of latex coating affected by the deformability of resin particles in convection drying

Latex paints are widely used, and many researchers pointed out that the film formation process depends on the deformability of dispersed polymer particles. However, the relationship between the film formation process and drying rate has not been totally understood due to the lack of accurate data on drying rate throughout the drying process. In the present study, we measured the drying rate of latex coating by the temperature change method proposed by Imakoma in convective drying. We revealed that the drying process significantly depends on particle deformability, especially in the former stage of the falling drying rate period. At a low drying temperature, the close-packed structure of polymer particles is formed throughout the film at the end of the constant drying rate period. On the other hand, partially deformed soft particles due to wet sintering inhibit the drying rate even under high moisture content at high drying temperatures. In either case, after forming the closest-packed structure, the shrinkage of the gap space between particles due to capillary deformation decreases the drying rate, proportional to the moisture content.

Multifunctional superhydrophobic surfaces

Surface wetting has a significant influence on the performance and applications of the materials. The superhydrophobic surfaces have water repellency due to low surface energy chemistry and micro/nanostructure roughness. The amazing applications of superhydrophobic surfaces (SHSs) lead to increase attention to superhydrophobicity in recent decades. The SHSs have been fabricated through chemical and physical methods. The further properties of SHSs as functions such as self-healing, anti-bacterial, anti-fouling, and stimuli-responsiveness are considered as the functions of the SHSs. The Multifunctional SHSs (MSHSs) that contained superhydrophobicity and at least two other properties as the next generation of the SHSs are swiftly developed in recent years. The multiple applications of the MSHSs are originated from specific morphology and functional groups of the MSHSs. The functions (properties) of the MSHSs are categorized into three groups including self-cleaning properties, restrictive properties, and smart properties. Designing and keeping surface structure plays a significant role in fabricating durable MSHSs. However, there is a big challenge to design and also scale up mechanochemical durable MSHSs. Based on state-of-the-art investigations, establishing a self-healing function can improve the durability of SHSs. The durable self-healing MSHSs can enhance the performance of the other functions and lifespan of the surface. In this review, all surface structures and superhydrophobic agents in MSHSs are investigated. The perspective of the MSHSs determined the next generation of the MSHSs have several significant parameters including durability, stability, more functions, more responsiveness, and environmentally friendly features for fabricating the large-scale MSHSs and enhancing their applications.