Chemical Modification of Guaran Gum. Part 3: Carboxymethylation in non-Aqueous Medium

Guar Gum-Based Macroporous Hygroscopic Polymer for Efficient Atmospheric Water Harvesting

Solar-driven atmospheric water harvesting technology has the advantage of not being limited by geography and has great potential in solving the freshwater crisis. Here, we first propose a purely natural and degradable superhydrophilic composite macroporous hygroscopic material by applying guar gum (GG) to atmospheric water harvesting. The material consists of GG-cellulose nanofibers (CNFs) as a porous substrate material, limiting the hygroscopic factor lithium chloride (LiCl) in its three-dimensional (3D) network structure, and carbon nanotubes (CNTs) play a photothermal conversion role. The composite material has a high light absorption rate of more than 95%, and the macroporous structure (20-60 μm) allows for rapid adsorption/desorption kinetics. At 35 °C and 90% relative humidity (RH), the moisture absorption capacity is as high as 1.94 g/g. Under 100 mW/cm2 irradiation, the absorbed water is almost completely desorbed within 3 h, and the water harvesting performance is stable in 10 cycles. Moreover, liquid water was successfully collected in an actual outdoor experiment. This work demonstrates the great potential of biomass materials in the field of atmospheric water collection and provides more opportunities for various energy and sustainable applications in the future.

Properties of galactomannans and their textile-related applications-A concise review

Galactomannans are reserve carbohydrates in legume plants and are primarily extracted from their seeds. They contain galactose side chains throughout the mannose backbone and have unique features such as emulsifying, thickening, and gelling together with biodegradability, biocompatibility, and non-toxicity, which make them an appealing material. Guar gum and locust bean gum mainly are used in all galactomannan needed applications. Nonetheless, tara gum and fenugreek gum have also attracted considerable attention in recent decades. Despite the increased usage of galactomannans in the textile-related fields in recent years, there is no review article published yet. To fill this gap and to demonstrate the striking and increasing importance of galactomannans, a concise summary of the properties of common galactomannans and their comparisons is given first, followed by an account of recent developments and applications of galactomannans in the textile-related fields. The associated potential opportunities are also provided at the end of this review.