Abstract
Pineapple is one of the most widespread crops in the world. High volume of pineapple leaf (PL) waste which is burnt directly on the farm or landfill site after harvest leads to negative impacts on the environment. However, PL residue can be considered an important potential source for renewable materials due to its significant cellulose content. As means to reduce waste and enhance cellulose-based materials, nanocellulose gains high attraction due to its special properties such as non-toxicity, biocompatibility, biodegradability, and 100 % environmental friendliness. Because of nanometer scale, nanocellulose becomes a promising material, which expresses high mechanical strength, extremely large surface area, good modifiability and results in various value-added applications, namely packaging, regenerative medicine, electronics, etc. Aiming to sustainability and feasibility, focusing on environmental-friendly resources like nanocellulose to generate high-value materials efficiently is one of the progressive actions. To summarize the common methods approached to utilize PL as raw materials to produce high-value engineering nanocellulose and its potential applications, this review focuses firstly on chemical and mechanical pre-treatment of PL to enrich cellulose content; secondly on the preparation of nanocellulose via conventional acid hydrolysis, enzymatic hydrolysis, and newly mechano-hydrolysis and its physicochemical properties as well as characteristic structure; finally on the sustainable applications of nanocellulose in production of renewable materials such as aerogel, hydrogel, nanocomposite, and other promising fields.
