Octadecyltrimethoxysilane is widely used as a surface modifier to impart hydrophobic properties to various materials. It is commonly applied in the treatment of glass, ceramics, and metals to create water-repellent surfaces, which are essential in industries like construction and automotive for anti-fogging and anti-corrosion purposes. In the field of nanotechnology, it is utilized to functionalize nanoparticles, enhancing their dispersion in organic matrices and improving the performance of composite materials. Additionally, it serves as a coupling agent in polymer composites, promoting adhesion between organic and inorganic components, which is crucial for enhancing mechanical strength and durability. Its application extends to coatings and paints, where it improves scratch resistance and weatherproofing.