SYNTHESIS OF POLYVINYL ALCOHOL/CHITOSAN NANOFIBERS AND THEIR APPLICATION AS ADSORBENT FOR CD(II) METAL IONS

• Main Author: MAYLINA TANJUNG ( NIM : 20514021 ), REVI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23915
• Institution: Institut Teknologi Bandung

Cd(II) ions is a heavy metal ions that causes water pollution and toxic because if accumulates in the body can lead to disruption of the reproductive system, kidney malfunction, and cause damage to the nervous system. Several ways have been done to reduce the content of heavy metal ions such as coagulation, electrochemical, precipitation, and ion exchange resins. However, these methods still have some weaknesses. Adsorption has been regarded as an effective and promising method because besides the cost is quite cheap, adsorption also sensitive to heavy metal ions. Nanofiber membranes have a specific surface area that is widely used as adsorbent to remove heavy metal ions. One of the compound that can be used as adsorbent is chitosan because it can be used to remove heavy metal ions. However, chitosan has a low chain flexibility, high viscosity and low mechanical properties, so it takes supporting polymer to help the formation of nanofiber. One of the materials that can be made into nanofiber is Polyvinyl Alcohol (PVA). PVA can provide hydroxyl groups on the surface of the nanofiber. Hydroxyl groups can also serve to absorb heavy metal ions. In this study, PVA/chitosan nanofibers have been synthesized by electrospinning method for adsorption of Cd(II) metal ions from solution. Synthesis is done by applying a optimum voltage, distance spinnerete - collector and the flow rate respectively 20 kV, 12 cm and 0.01 mL/min. Nanofiber characterized using optical microscopy, SEM (Scanning Electron Microscopy) and TEM (Transmition Electron Microscopy) to morphology analysis, FTIR (Fourier Transform Infrared) to analysis of structure and BET (Braunanear, Emmelt and Teller) to analysis of surface area. The result of SEM obtained diameter of the nanofiber with an average 294.5 nm for PVA and 176.5 for PVA/chitosan. The adsorption process is done by optimization of pH, initial concentration, contact time and adsorbent mass. The optimum conditions PVA and PVA/chitosan nanofibers for adsorption of Cd(II) metal ions at pH 7, the initial concentration of 15 mg/L, contact time of 180 minutes, and adsorbent mass of 0.02 g with a maximum adsorption capacity of 9.67 mg/g and 10.64 mg/g. Adsorption of Cd(II) ions using PVA/chitosan nanofibers followed the Langmuir isotherm model and pseudo second-order kinetic. <br />