Isolation of Thermally Stable Cellulose Nanocrystals from Spent Coffee Grounds via Phosphoric Acid Hydrolysis

As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This rapid growth in food production results in an ever increasing amount of agricultural wastes,of which already occupies nearly 50%of the total landfill area.For example,is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually.This paper seeks to provide a method for isolating cellulose nanocrystals(CNCs)from spent coffee grounds,in order to recycle and utilize the cellulosic waste material which would otherwise have no applications.CNCs have already been shown to have vast applications in the polymer engineering field,mainly utilized for their high strength to weight ratio for reinforcement of polymer-based nanocomposites.A successful method of purifying and hydrolyzing the spent coffee grounds in order to isolate usable CNCs was established.The CNCs were then characterized using current techniques to determine important chemical and physical properties.A few crucial properties determined were aspect ratio of 12±3,crystallinity of 74.2%,surface charge density of(48.4±6.2)mM/kg cellulose,and the ability to successfully reinforce a polymer based nanocomposite.These characteristics compare well to other literature data and common commercial sources of CNCs.

Mycelium as a self-growing biobased material for the fabrication of single-layer masks

Disposable face masks are an essential piece of personal protective equipment for workers in medical facilities,laboratories,and the general public to prevent the spread of illnesses and/or contamination.Covid-19 resulted in an uptick in the usage and production of face masks,exacerbating issues related to the waste and recycling of these materials.Traditionally,face masks are derived from petrochemicals,such as melt-blown or spunbound polypropylene.As such,there is a need to find sustainable mask materials that can maintain or improve the performance of petrochemical masks.This paper explores an alternative mask material that utilizes fungal mycelium as self-growing filaments to enhance the efficiency of individual polypropylene mask layers.By engineering the growth pattern and time,breathability and filtration efficiency was optimized such that one layer of the mycelium-modified mask could replace all three layers of the traditional three-layer mask.Additionally,it was found that the mycelium-modified mask exhibits asymmetric hydrophobicity,with super-hydrophobicity at the composite-air interface and lower hydrophobicity at the composite-medium interface.This property can improve the performance of the modified mask by protecting the mask from external liquids without trapping water vapor from the user’s breath.The findings from this study can provide a basis for further development of mycelium to create sustainable filtration materials with enhanced functionality.