Composite membranes of cellulose–mesoporous silica: optimization of membrane fabrication and adsorption capacity

• Published in: Cellulose (London) Vol. 30; no. 1; pp. 339 - 357
• Main Authors: Miri, Simin, De Girolamo, Anthony, Nadeem, Humayun, Chin, Benjamin Wey Xien, Hora, Yvonne, Andrews, Philip C., Batchelor, Warren
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2023; Springer Nature B.V
• Subjects: Adsorption; Adsorptivity; Bioorganic Chemistry; Bleaching; Cellulose; Cellulose fibers; Ceramics; Chemistry; Chemistry and Materials Science; Composites; Epichlorohydrin; Eucalyptus; Glass; Heavy metals; Industrial applications; Kraft pulp; Membranes; Methylene blue; Natural Materials; Optimization; Organic Chemistry; Original Research; Particulate composites; Physical Chemistry; Polyamide resins; Polyelectrolytes; Polymer Sciences; Production costs; Silicon dioxide; Sustainable Development; Tin; Adsorption; Mesoporous silica; Cellulose; Composite membrane; Pulp; Depth filtration
• ISSN: 0969-0239; 1572-882X
• DOI: 10.1007/s10570-022-04908-9

In this work, we produced composites of mesoporous silica synthesized in-situ on never-dried bleached eucalyptus kraft pulp fibers with the aim of providing cost-effective depth filters, having high flux, and adsorptivity. The mesoporous silica loading for the produced samples was in the range of 12–35 wt%. The performance of double-layer membranes was studied for the adsorption of charged molecules. The best nanofibrillated cellulose-pulp-mesoporous silica membrane adsorbed 1160 mg/m 2 of methylene blue and had a flux of 10 L m −2  h −1  bar −1 . The nanofibrillated cellulose layer supported the pulp-mesoporous silica layer and improved the adsorptivity of the pulp-mesoporous silica depth filter layer by controlling flux. The membranes showed non-linear-pseudo-first-order adsorption kinetics and non-linear Freundlich isotherm for methylene blue adsorption. The nanofibrillated cellulose-pulp-mesoporous silica membrane was modified for metanil yellow adsorption by adding polyamide amine-epichlorohydrin resin. The best metanil yellow saturated adsorption capacity was 9400 mg/m 2 . The nanofibrillated cellulose-pulp-mesoporous silica depth filter without modification with a polyelectrolyte also had 92% and 94% heavy metal removal of 20 mg of Cu 2+ and Pb 2+ ions, respectively. The novel pulp-mesoporous silica composite membrane, with high adsorption capacity and manufactured by lower embodied energy of cellulose fiber, can significantly lower large-scale depth filter production costs due to the elimination of cellulose pre-treatment for the depth filter layer. The reusability performance in the fifth cycle, after four cycles of metanil yellow adsorption and desorption, was 5.2 mg/g, which was stabilized from the 3rd to 5th cycles. This suggests the suitability of these membranes for industrial applications.