The document discusses studies on carbon fibre composites. It introduces composites and various natural and synthetic fibres used in composites like carbon, glass, sisal etc. It describes advantages of carbon fibre like strength and light weight. Advantages of sisal fibre include low cost and flexibility. The document outlines methods to modify fibre surfaces including physical, chemical and silane treatments. It also discusses challenges with sisal and carbon fibres and different composite manufacturing methods. Finally, it summarizes various literature on using silane treatments and alkali treatments to improve mechanical properties of fibre-reinforced composites.