Mesoporous silicas with hexagonal structure (MCM-41 and SBA-15) and cubical interconnected pore structure (KIT-6) were synthesized and modified with aminopropyltriethoxysilane (APTES) for using as adsorbents in carbon-dioxide (CO₂)-adsorption application. The CO₂-adsorption experiment was carried out at room temperature and atmospheric pressure using 15% CO₂ with a flow rate of 20 mL/min and the desorption experiment was carried out at 100°C under N₂ balance with a flow rate of 20 mL/min. The adsorption capacity and adsorption rate of all modified mesoporous silicas were enhanced due to the presence of primary amine in the structure, which was able to form a fast chemical reaction with CO₂. All adsorbents showed good adsorption performance stability after using over five adsorption/desorption cycles. Due to the effect of the adsorbents’ porous structure on the adsorption/desorption process, an adsorbent with sufficient pore-size diameter and pore volume together with interconnected pore, KIT-6, represents a promising adsorbent that gave the optimum adsorption/desorption performance among others. It showed reasonable adsorption capacity with a high rate of adsorption. In addition, it could also be regenerated with 99.72% efficiency using 12.07 kJ/mmolCO₂ of heat duty for regeneration.

High-surface-area, hexagonal-structured mesoporous silica, MCM-41, was synthesized and wet impregnated with three different amines of 2-(ethylamino) ethanol (EAE), ethylenediamine (EDA), and tetraethylenepentamine (TEPA) for use as solid adsorbents in post-combustion CO₂ capture application. The CO₂ adsorption test was performed at 25°C and atmospheric pressure using 15/85 vol% of CO₂/N₂ at a 20-mL/minute flow rate. Desorption was carried out at 100°C under 20 mL/minute of N₂ flow. The results show that the capacity and rate of CO₂ adsorption obtained from all the amine-modified adsorbents were significantly increased with increasing amine loading due to carbamate formation. Desorption efficiency and heat duty for regeneration were also affected by the amount of amine loading. The more stable the carbamate produced, the higher the energy was required. They exhibited the highest adsorption–desorption performance at 60 wt% amines used for impregnation. Blended EAE/TEPA at different weight ratios at a total concentration at 60 wt% amines was impregnated on MCM-41 adsorbent. Sorbent impregnated with 50%/10% of EAE/TEPA showed the best performance of 4.25 mmolCO₂/g at a high adsorption rate, a low heat duty of 12 kJ/mmolCO₂ and with 9.4% reduction of regeneration efficiency after five repeated adsorption–desorption cycles.

Polymer film coating with a highly hydrophobic surface property is a practical approach to prevent fouling of any structures in the marine environment without affecting marine microorganisms. The preparation of a polymer coating, from a simple and easy method of solution blending of hydrophobic polydimethylsiloxane elastomer and hydrophilic polyurethane with SiO₂, was carried out in this study, with the aim of improving characteristics, and the coating demonstrated economic feasibility for antifouling application. Incorporation of SiO₂ particles into PDMS and PDMS/PU polymer film improved mechanical properties of the film and the support fabrication of micropatterns by means of a soft lithography process. Observations from field emission scanning electron microscope (FESEM) of the PDMS/SiO₂ composite film revealed a homogeneous morphology and even dispersion of the SiO₂ disperse phase between 1–5 wt.%. Moreover, the PDMS film with 3 wt.% loading of SiO₂ considerably increased WCA to 115.7° ± 2.5° and improved mechanical properties by increasing Young’s modulus by 128%, compared with neat PDMS film. Additionally, bonding strength between barnacles and the PDMS film with 3 wt.% of SiO₂ loading was 0.16 MPa, which was much lower than the bonding strength between barnacles and the reference carbon steel of 1.16 MPa. When compared to the previous study using PDMS/PU blend (95:5), the count of barnacles of PDMS with 3 wt.% SiO₂ loading was lower by 77% in the two-week field tests and up to 97% in the eight-week field tests. Subsequently, when PDMS with 3 wt.% SiO₂ was further blended with PU, and the surface modified by the soft lithography process, it was found that PDMS/PU (95:5) with 3 wt.% SiO₂ composite film with micropatterns increased WCA to 122.1° ± 2.9° and OCA 90.8 ± 3.6°, suggesting that the PDMS/PU (95:5) with 3 wt.% SiO₂ composite film with surface modified by the soft lithography process could be employed for antifouling application.