Curing of Cellulose Hydrogels by UV Radiation for Mechanical Reinforcement

Abstract

The use of biomaterials as a replacement for thermoplastic polymers is an environmentally sound strategy. In this work, hydrogels of cellulose isolated from wheat husk were modified by UV irradiation (353 nm) to improve mechanical performance. The cellulose was dissolved with a solvent system N,N-dimethylacetamide/lithium chloride (DMAc/LiCl). Infrared spectroscopy showed that the peak height at 1016 cm−1, associated with the C–O bonds of the glycosidic ring, increases with irradiation time. It was determined that the increase in this signal is related to photodegradation, the product of a progressive increase in exposure to UV radiation. The viscoelastic behavior, determined by dynamic mechanical analysis and rotational rheometry, was taken as the most important parameter of this research, showing that the best results are recorded with 15 min of UV treatment. Therefore, at this time or less, the chemical crosslinking is predominant over the photodegradation, producing an increase in the modules, while with 20 min the photodegradation is such that the modules suffer a significant reduction.

Gels in Motion: Recent Advancements in Energy Applications

“…The absence of strict or uniform regulation imposes a major challenge in techniques like 3D-bioprinting, which is added with high cost and imposes enormous production challenges, particularly in intercontinental transport [99]. In the production of bioink formulation with the capabilities of cell viability and printability, the rate of curing is an essential step that determines the production rate of bioink; thus, the precise control of curing is critical [100]. Thus, the large scale production of effective hydrogels in complex requires skilled chemical understanding and well-documented, strict regulations.…”

Cellulose-Based Metallogels—Part 1: Raw Materials and Preparation

“…The resulting cellulose solution may be transparent or colored in yellow in the case of lignocellulose, or green, yellow or brown when the waste paper was dissolved directly [95]. In [106], the solutions were additionally undergone a UV irradiation (353 nm) to improve mechanical performance.…”

“…The solvent system DMAc/LiCl has been implemented for hydrogel production from cellulose of various origins. The reported sources of cellulose were conventional plant-derived, namely cotton, hardwood pulp, and more sustainable short-length flax fibers [86,103], bamboo [104,105], rice straw, sugarcane bagasse, thanaka heartwood [85], wheat husk [106], waste paper and cardboard [93].…”

“…Gelation of the cellulose solutions in DMAc/LiCl occurs by spontaneous self-assembly and aggregation of lignocellulose chains in ambient conditions with a humid atmosphere for a period from 12 h up to 7 days [86,95,106]. Cruz-Medina and co-authors claimed that moisture of the atmosphere plays the role of antisolvent to coagulate cellulose [102].…”

Some Bond-Additive indices and Its Polynomial of Cellulose

“…It aids in the modeling of a wide range of systems, the structure and operation of which are influenced by the connection patterns of its constituent parts. Modern materials science needs have encouraged the creation of a wide range of bio-based materials, in which cellulose and its derivatives play a significant part, as a reaction to environmental concerns in [3,8,11,18,21,29]. Because of cellulose's exceptional and one-of-a-kind chemical and physical properties, it has received wide recognition in a number of industries.…”