3D Printed PEGDA/HEMA-Polysaccharide Hybrid Monoliths for Aqueous Dye Adsorption

With the continuous advancement of technology, 3D printing (3DP) has emerged as an invaluable tool across various scientific and engineering disciplines. This study demonstrates the versatility of resin-based 3DP in fabricating functional monolithic structures for wastewater treatment applications. Specifically, it explores the design flexibility and adsorption capabilities of 3D printed monoliths toward both anionic and cationic dyes under varying pH conditions. The monoliths were fabricated using masked stereolithography (MSLA) with biocompatible photopolymer resins such as poly (ethylene glycol) diacrylate (PG) and 2-hydroxyethyl methacrylate (HM) mixed with different polysaccharides such as starch (STC), chitosan (CS), pectin (PEC), and sodium alginate (SA) to form hybrid PG-HM lattice cubes. The surface morphology of the printed monoliths was characterized by field emission scanning electron microscopy (FESEM). Batch adsorption experiments were conducted using both pristine PG-HM and hybrid PG-HM monoliths against cationic dyes, Rhodamine B (RhB) and methylene blue (MB), and anionic dyes such as Congo red (CR) and methyl orange (MO) under controlled conditions. The consistent parameters are 50 ppm dye concentration, pH 7, room temperature, one monolith unit dosage, and 150 rpm agitation. Further studies were performed to evaluate the effects of pH by varying the pH values from 3, 5, 9, and 11 on dye adsorption performance. The hybrid PG-HM structures exhibited a non-uniform distribution of polysaccharides within the cured resin matrix, resulting in a noticeably rougher surface morphology. CS and SA hybrid monoliths exhibited markedly enhanced dye removal efficiencies, achieving over 80% removal of methyl orange at pH 3 and methylene blue at pH 11. In contrast, STC and PEC composites demonstrated only marginal improvements compared to pristine PG-HM monolith. These findings highlight the critical role of polysaccharide incorporation in influencing adsorption behaviour and underscore the potential of sustainable resin-based 3DP for designing customizable materials in advanced in wastewater treatment applications.