Spent mushroom substrates (SMS) are abundant by-products in agriculture generated by commercial mushroom industries after the harvesting period of mushrooms. If not utilized, a huge amount of SMS is difficult to handle and is discarded through disposal and burning methods, which negatively affect the environment. Coir fiber (CF) is abundantly available in tropical countries and is one of the toughest natural fibers and a rich source of cellulose. The cellulose content from both Ganoderma lucidum SMS and CF was combined for the first time to produce thermal-insulating cellulose-based aerogels via an environmentally friendly and cost-effective freeze-drying process. The effect of the ratio of G. lucidum SMS and CF on the density, porosity, hydrophobicity, and thermal properties of aerogel composites was comprehensively investigated. The as-fabricated aerogel showed an exceedingly low density of 0.096–0.116 g cm^−3 with a high porosity of more than 92%. Due to the porous structure inside, the cellulose-based aerogels exhibit outstanding heat insulation with an extraordinarily low thermal conductivity of 0.039–0.0559 W m^−1 K^−1, which are comparable to commercial insulation materials such as mineral wool, foam glass, polystyrene, and glass wool. The water contact angles were measured on both the surface and cross-section of the cellulose-based aerogels, ranging from 92^o to 115^o, which demonstrated their hydrophobic nature. The research results increase the possibility of applying the developed cellulose-based aerogel from agricultural biomass to practical heat insulation applications.
Roque B. Porcel is a senior Biology student majoring in Microbiology at Polytechnic University of the Philippines-Manila (PUP-Manila). He is from Tabaco City, Albay, and is a proud Uragon. He completed high school as a special science student at Tabaco National High School (TNHS). He graduated senior high school with high honors at Polytechnic University of the Philippines-Manila (PUP-Manila). He developed a strong interest in science during his elementary school years when he was fascinated by the mechanisms behind illness and recovery. In the future, he wants to serve the Filipinos by becoming a Doctor to the Barrios and inspiring younger generations to follow in his footsteps. During his third year in college, his research group received a research grant worth 250 thousand pesos for their study entitled "Fabrication of Aerogel with Heat Insulation Properties from Spent Mushroom Substrate and Coir Fiber." Throughout his college years, he dedicated his time as a student volunteer at the Mycology Laboratory where he was involved in a lot of projects including the Myconema and Balik Scientist Program under Dr. Jennifer Luangsa-ard. His research interests are in Microbiology, Mycology, Biomedical Science, and Material Science.