Fabrication of Green Diatomite/Chitosan-Based Hybrid Foams with Dye Sorption Capacity

Abstract

The latest tendency of the scientific community regards the development of different classes of green materials able to solve pollution problems caused by industrial and human activity. In this paper, chitosan and diatomite were used to produce a broad-spectrum hybrid adsorbent, either in powder or in monolithic form for environmental pollutant removal. Diatomite–chitosan-based powders and porous diatomite–chitosan hybrids were prepared and characterized by chemical-physical, thermal and morphological analysis. Moreover, their adsorbent capacity towards anionic dye (Indigo Carmine) was also evaluated. Obtained data showed that chitosan improves the adsorption capacity of both systems, increasing the uptake of dye in both diatomite–chitosan systems.

Open-Celled Foams from Polyethersulfone/Poly(Ethylene Glycol) Blends Using Foam Extrusion

“…Furthermore, the dye uptake test revealed uptake of the solution of 1-1 methylene blue in ethanol due to the color changing from white to blue. This indicated that the capillary effect enabled the absorption of the solution into the foam, thus confirming the open cellularity [ 101 , 102 , 103 ].…”

Tapping the potential of a glucosamine polysaccharide-diatomaceous earth hybrid adsorbent in the solid phase extraction of a persistent organic pollutant and toxic pesticide 4,4′-DDT from water

“…The FT-IR spectrum of chitosan-diatomaceous earth hybrid before adsorption has well dened peaks at 1089 cm À1 which is indicative of the C-O skeletal vibrations and at 3116-3268 cm À1 reecting the N-H and O-H stretching band vibrations. 43 As obvious 2883 cm À1 is a characteristic trait of C-H stretching vibration. Vibrations at 1660 cm À1 corresponds to C]O stretching of amide bond.…”

“…Vibrations at 1660 cm À1 corresponds to C]O stretching of amide bond. The Si-O and Si-O-Si groups 43,44 and the deformations are observed around 620 cm À1 . The FTIRspectra aer adsorption of 4,4 0 -DDT showed a denite shi in N-H vibrational frequency to 3268 cm À1 indicating that the amine groups are indeed involved in the interaction mechanism.…”

Excellent regeneration, easy separation and high capacity of 3D chitosan–melamine sponge composites for anionic dye removal

“…However, the obtained chitosan-based materials are mostly powder, which is easy to block and complicated to reuse in the face of common separation methods. 20,21 Thus, non-traditional chitosan adsorbents including beads, 22 fibers, 23 and foams 24 are developed to overcome the above-mentioned problems. These adsorbents with various morphologies have mechanical strength to some extent but have shortcomings such as weak elasticity and difficulty in generating micropores.…”