Paper Doped with Polyacrylonitrile Fibres Modified with 10,12–Pentacosadiynoic Acid

This work reports a modification of a fibrous cellulose material (paper) by the addition of polyacrylonitrile (PAN) fibres doped with 10,12–pentacosadiynoic acid (PDA). The fibres are sensitive to ultraviolet (UV) light. When the paper containing PAN–PDA is irradiated with UV light it changes colour to blue as a consequence of interaction of the light with PDA. The colour intensity is related to the absorbed dose, content of PAN–PDA fibres in the paper and the wavelength of UV radiation. The features of the paper are summarised after reflectance spectrophotometry and scanning microscopy analyses. All the properties of the modified paper were tested in accordance with adequate ISO standards. Moreover, a unique method for assessing the unevenness of the paper surface and the quality of printing was proposed by using a Python script (RGBreader) for the analysis of RGB colour channels. The modification applied to the paper can serve as a paper security system. The modified paper can act also as a UV radiation indicator.

Optimization of Bioethanol Synthesis from Durian Seeds Using Saccharomyces Cerevisiae in Fermentation Process

Bioethanol is an alternative energy of environmentally friendly as a substitute for petroleum. Sucrose, starch, and fibrous cellulose (lignocellulose) are the main ingredients for bioethanol production. The material is very easy and abundant to get from the waste of agricultural crops. One of these agricultural wastes in Indonesia that have not been used optimally is durian seeds. Durian seeds only become waste and are not commercially useful, even though they contain high carbohydrates, which is possible as a potential new source for bioethanol production. In this work, an experimental study was conducted on bioethanol synthesis from durian seeds through fermentation by Saccharomyces cerevisiae yeast in aerobic fermenter. The process for the production of starch-based bioethanol includes milling, hydrolysis, detoxification, fermentation, and distillation. At the stage of fermentation, variations in the duration of fermentation were applied for 1-11 days. Carbohydrates contained in durian seed flour are 11.541%, which is the largest content. The highest result of ethanol content is 14.72 % (v/v) in 9 day fermentation periods by using Saccharomyces cerevisiae in aerobic conditions. Distillation to enrich bioethanol was carried out by batch vacuum distillation at 68°C for ± 180 minutes and produced bioethanol with a purity of 95%.