Production and characterization of hemicellulose-based halochromic gel pen

Abstract

This study aims to produce an environmentally friendly, economical, and hemicellulose-based halochromic polymeric gel pen which will be equivalent to traditional pH indicators. The tea pulp (TP) was used as a hemicellulose resource in the research. The experimental study was carried out in three stages. In the first step, the tea pulp was supplied, and the hemicellulose was isolated from these resources by the delignification process. Then, halochromic polymeric gel tips were synthesized by the free radical polymerization method. The produced gel tips which can be used repeatedly, have a cross-linked polymeric gel structure. In the last step, the produced gel tips were characterized using analytical and instrumental analysis methods, and a suitable pen was designed and produced to gel tips. The response of the gel-tip pen to pH change was very high (between 5 and 15 s). Its solubility (max 2%) in distilled water was very low. Because the equilibrium swelling capacity (2.5 g water/g gel tip) for the gel tip with the optimum composition was very low, the gel tip did not undergo size deformation in the solution medium. The color change of the gel tip was reversible and could be used repeatedly. It degraded 98% in the soil flora after 60 days, thus it is biodegradable and does not cause environmental pollution. In these respects, the study creates economic added value in terms of solid waste assessment. Unlike its counterparts, it does not lead to water and environmental pollution, and it is easy to use and practical. [GRAPHICS] .