Superhydrophobic coatings are beneficial for applications like self-cleaning, anti-corrosion, and drag reduction. In this study, we investigated the impact of surface geometry on the static, dynamic, and sliding contact angles in the Cassie–Baxter state. We used fluoro-silane-treated silicon micro-post patterns fabricated via lithography as model surfaces. By varying the solid fraction (ϕ_s), edge-to-edge spacing (L), and the shape and arrangement of the micro-posts, we examined how these geometric factors influence wetting behavior. Our results show that the solid fraction is the key factor affecting both dynamic and sliding angles, while changes in shape and arrangement had minimal impact. The Cassie–Baxter model accurately predicted receding angles but struggled to predict advancing angles. These insights can guide the development of coatings with enhanced superhydrophobic properties, tailored to achieve higher contact angles and customized for different environmental conditions.

A novel approach for synthesizing polymer particles that encapsulate Fe₃O₄ nanoparticles using γ-ray irradiated mini-emulsion polymerization is presented. To achieve high encapsulation efficiency, the surface properties of Fe₃O₄ nanoparticles are modified from hydrophilic to hydrophobic, allowing for effective dispersion in the monomer prior to polymerization. Mini-emulsion techniques have proven essential for forming the encapsulated structure and controlling particle size distribution. γ-ray irradiation initiated radical polymerization and solidified the emulsion structure. Characterization via FTIR, XRD, and TEM confirmed the successful encapsulation of Fe₃O₄ nanoparticles within polymer particles. Magnetic measurements demonstrated superparamagnetic behavior and high magnetic induction, both of which are properties considered advantageous for biomedical applications.

Epoxy nanocomposites are widely used in various applications because of their excellent properties. Different types of manufacturing techniques are used to produce epoxy composites based on various fillers, molecular weight, and applications required. The physical properties and chemical structure of epoxy resin help in determining the method for its manufacturing. Coatings and adhesive formulations are prepared using high- molecular-weight epoxies, whereas epoxy nanocomposites require low-molecular-weight epoxies due to ease of manufacturing. A low-molecular-weight epoxy can provide high crosslink density to the epoxy but may also cause inherent brittleness in epoxy nanocomposites. Further, the addition of CNTs may also cause more brittleness in the final product. In this work, the authors have developed a method to process composites based on high-molecular-weight epoxy reinforced with high loading of CNTs (15 wt.%). The high molecular weight will bring lots of challenges during manufacturing. In this paper, a novel manufacturing technique based on separate molding and curing conditions to produce highly concentrated CNT-filled epoxy with high-molecular-weight epoxy resin is described, achieving excellent mechanical properties, good toughness, and high electrical conductivity in an efficient, low-cost, environmentally friendly, and high-volume way. The findings demonstrated improvements in these mechanical properties compared to conventional systems. They also highlight the potential of the novel method to develop advanced composite materials which can revolutionize industrial sectors such as aerospace, automotives, and electronics where structural integrity and thermal stability are important.

A simple and innovative synthesis strategy was established to produce polymer microspheres with a distinctive walnut-like morphology, incorporating Fe₃O₄ nanoparticles within their structure. This was achieved through γ-ray-initiated mini-emulsion polymerization. To ensure high encapsulation efficiency, the surface of the Fe₃O₄ nanoparticles was chemically altered to shift their wettability from hydrophilic to hydrophobic, enabling uniform dispersion within the monomer phase before polymerization. The formation of the walnut-like architecture was found to be significantly influenced by both the polymerization dynamics and phase separation, as well as the shrinkage of the crosslinked polymer network formed between the monomer and the resulting polymer. Divinylbenzene (DVB) was chosen as the monomer due to its ability to generate a mechanically stable polymer framework. The γ-ray irradiation effectively initiated polymerization while preserving structural coherence. A detailed analysis using FTIR, SEM, and TEM confirmed the successful fabrication of the Fe₃O₄-loaded polymer microspheres with their characteristic textured surface. Moreover, magnetic characterization via vibrating sample magnetometry (VSM) indicated pronounced superparamagnetic behavior and strong magnetic responsiveness, highlighting the potential of these microspheres for advanced biomedical applications.

The development of PFAS-free (per- and polyfluoroalkyl substances), liquid-repellent surfaces require a fundamental understanding of how surface geometry governs wetting-state stability. However, the independent role of interparticle spacing remains poorly understood because it is often coupled with changes in particle size, surface chemistry, or hierarchical morphology. Here, we present a geometry-driven strategy to systematically investigate the influence of spacing using re-entrant spherical architectures with controlled spacing ratios. Monodisperse 1 μm silica particles were immobilized within an epoxy matrix, while sacrificial 1 μm polystyrene spheres served as inert spacers to precisely tune interparticle distance without altering particle size or surface chemistry. After spacer removal and conformal hydrophobic silanization, wetting behavior was evaluated using ethanol–water mixtures with surface tensions ranging from 71.93 to 22.28 mN m–1. The apparent contact angle exhibits a nonmonotonic dependence on spacing ratio for liquids with surface tensions above approximately 25 mN m–1, reflecting a critical trade-off between reduced solid–liquid contact fraction, which enhances repellency, and diminished Cassie–Baxter state stability, which promotes wetting transition. As surface tension decreases, the optimal spacing ratio shifts toward smaller values, indicating increasingly stringent geometric requirements for sustaining the suspended wetting state. A theoretical framework integrating the Cassie–Baxter and Wenzel models with a breakthrough-pressure criterion quantitatively captures the experimental trends. These findings establish predictive design rules for geometry-controlled wetting and provide a scalable pathway for engineering high-performance, PFAS-free liquid-repellent coatings.