SYNTHESIS OF COMPOSITE HYDROGEL USING LIGNIN H2SO4 ISOLATED FROM COFFEE SKIN AS METHYLENE BLUE ADSORBENT Tengku Adetya Nurhaliza, Dr.Diana Alemin Barus,M.Sc, Dr.Syahrul Humaidi,M.Sc
Postgraduate Program (Physics),FMIPA
Jln Bioteknologi No 1 Medan, Universitas Sumatera Utara
Abstract
Abstract:The synthesis of hydrogel composite based on coffee husk has been carried out by crosslinking method. The method applied by the addition of lignin H2SO4 isolated from coffee husk was 0.05%, 0.1%, 0.2%, 0.3%, the addition of 2 g of CNF and the addition of 5% PVA for each variation. From the prepared composite hydrogel samples, physical and chemical properties were tested using several measurement techniques for several characterizations. Characterizations applied include characterization of water absorption, methylene blue absorption, characterization of functional groups, characterization of microcrystalline properties, morphological characterization and characterization of mass reduction on thermal treatment. From the results of the characterization, the results are interrelated and mutually supportive. The best sample belongs to the hydrogel sample HYD-005 which has a water absorption capacity of 55% and an effective absorbance of methylene blue which is 81% in every hour applied. The measurement of the absorbance of methylene blue is also applied to variations in temperature, namely 350C, 450C, 550C. From the applied temperature variation, the absorbance values obtained were 59%, 53% and 81%, respectively. Of all the samples synthesized, the HYD-005 sample has the best value from other samples, this is supported by each characterization and analysis obtained.
