Efek Variasi Konsentrasi NaOH pada Pembentukan Struktur Selulosa Cladophora sp.

Abstract

The effect of NaOH concentration values was observed on the cellulose structure of Cladophora. Cladophora cellulose is synthesized from Cladophora sp., a green alga that lives in aquatic environments (seawater and freshwater) and soil surfaces (rocks and wetlands). Cellulose synthesis is carried out through the processes of bleaching, alkali hydrolysis, and acid hydrolysis. Bleaching uses NaClO2, alkaline hydrolysis uses NaOH with varying concentrations (0.4; 0.5; 0.6; 0.7; 0.8 M), while acid hydrolysis uses 5% HCl. The physical properties of cellulose were analyzed using Fourier Transformation Infra-Red (FTIR) to determine functional groups, X-Ray Diffraction (XRD) to determine crystal structure, and scanning electron microscopy (SEM) to determine the morphology of cellulose structure. FTIR pattern analysis showed peaks with OH group stretching at 3331, 3347, 3360 cm-1 , CH group stretching at around 2929 cm-1 , C = O stretching at 1640-1650 cm-1 , and CH2 flexural stretching at 1420-1430 cm-1 in all samples. XRD pattern analysis confirmed the recovery of Cladophora cellulose from a highly crystalline of sample c (NaOH 0.5 M) with a crystallinity index of 94.0 % and a particle size of 31.54 nm. SEM image analysis showed the surface morphology of Cladophora rod-shaped raw material with an average diameter of 21.30 µm. At the same time, Cladophora cellulose refers to the formation of a web-like nanofibril network with an average diameter of 30.63 nm. These results indicate that the synthesis has successfully removed lignin, hemicellulose, and amorphous group in Cladophora and formed crystalline cellulose confirmed by nano-sized cellulose.