THE SYNTHESIS OF ETHYLENEDIAMINE-MODIFIED POLYACRYLONITRILE NANOFIBER USING ELECTROSPINNING METHOD FOR THE ADSORPTION OF DI-(2-ETHYLHEXYL) PHTALATE

• Main Author: Rizqia Zahra, Ridha
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/62883
• Institution: Institut Teknologi Bandung

Di-(2-ethylhexyl) phthalate (DEHP) is the most widely used phthalic acid ester (PAE) commercially as a plasticizer and can cause pollution in the aquatic environment. This is because DEHP is not chemically bound to the polymer matrix so that it can migrate to the environment easily. These compounds can also disrupt the endocrine system so that it threatens human health. DEHP removal methods that have been developed so far include biodegradation, chemical oxidation and adsorption. However, biodegradation and chemical oxidation have disadvantages in terms of incomplete degradation and long operation times of DEHP removal. As for the adsorption method, the application of micro and nano- sized adsorbents faces challenges related to difficulties in separation and recovery for reuse. To avoid this limitation, material synthesis was carried out using the electrospinning method to produce nanofibers that are easily separated by precipitation or filtration. This study aimed to synthesize polyacrylonitrile (PAN) nanofibers modified with ethylenediamine (EDA) that can be applied as DEHP adsorbents. PAN nanofibers were made using the electrospinning method by optimizing the parameters of concentration, flow rate, distance and voltage. Nanofiber characterization was carried out using Forier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy – Energy Dispersive Spectroscopy (SEM-EDS), Brunaeur-Emmett-Teller (BET), and zeta potential analysis. The optimization results based on fiber imaging using a digital and optical microscope showed the optimum conditions for making PAN nanofibers at a concentration of 18%, flow rate of 0.5 Lmin-1, distance of 15 cm and voltage of 9.5 kV. Modification with EDA obtained the optimum immersion time of 2 hours. The FTIR spectrum showed that modification with EDA made the 3300-3550 cm-1 peak (NH stretching) stronger and wider, increased the peak intensity at 1630- 1670 cm-1 (C=N vibration) and decreased the intensity of the nitrile and carbonyl peaks at 2243 cm-1 and 1737 cm-1. Characterization with SEM showed that modification with EDA increased fiber diameter and produced a rough fiber surface compared to PAN without modification. The results of zeta potential analysis showed that the surface charges of PAN and PAN-EDA were -2.8 mV and +20.03 mV respectively at adsorption pH. PAN-EDA nanofibers showed better adsorption of DEHP than PAN nanofibers without modification. Based on the literature review, DEHP adsorption tends to follow the Langmuir isotherm model and pseudo-second-order kinetics.