Heavy metal adsorption (HMA) is one of the remediation techniques used to remove heavy metals from water/wastewater. Composite membranes with functionalized additives for selective adsorption are being investigated. In this study, Carbon Quantum Dots – Polyacrylonitrile/Polycaprolactone nanocomposite membranes are synthesized by electrospinning which is intended for HMA of Cu2+. The nanofiber mats were characterized using SEM, FTIR, and Contact Angle. Batch adsorption process were performed and to utilize the AAS for kinetic adsorption behavior analysis. SEM micrographs revealed the addition of CQD in PAN and PAN/PCL membrane matrix shifted the fiber size distribution from 50 – 100 nm to 150 – 250 nm indicates the decrease in effective surface area. FTIR analysis exhibited vibrational peaks and binding of distinct functional groups such as amine, nitrile, carboxylic, hydroxyl, and carbonyl for CQD, PAN and PCL, respectively. CQD in aqueous form further increases the hydrophilicity of PAN/PCL membrane matrix which is essential for HMA of Cu2+ ions. The increase of nanofiber mat’s adsorption capacity with respect to contact time obtained a maximum at 63.45 mg/g with a maximum efficiency of adsorption at 90.74%. Kinetic adsorption studies show that the pseudo – first order kinetic model best fits the data for CQD – PAN/PCL nanofiber mat in Cu2+ ions obtaining a correlation value of R2 = 0.9418 and a rate constant k = 0.0172 min1 indicating the adsorption behavior follows the physical adsorption process involving Van der Waals forces and hydrogen bonding between the adsorbent and adsorbate.

Copper Nanoparticle (CuNP) is mi xed as nanofiller to Acrylonitrile Butadiene Styrene (ABS) to pro duce a material that can control bacterial growth on material surfaces and improve antibacterial performance . The nanoco mposite i s produced via melt compounding using a twin-screw ext ruder. Three samples are prepared with 0%, 1.5% and 3% Copper Nanoparticle loading . Th e samples are extruded , placed in a mold and processed in a compression molding machine. The samples were characterized using Fourier Transform Infrared Spectroscopy (F TI R), X-ray Diffraction (XRD), Dynamic Mechanical Testing (DMA) and Antibacterial Testing. Results from FTIR shows presence of molecular vibrations of Acrylonitrile, Butadiene and Styrene groups with the presence of foreign substances identified as an addi ti ve used in commercial ABS production. XRD showed t he incorporation of copper nanoparticles in the nanocomposites. DMA results shows that the incorporation of copper nanoparticles into the ABS matrix results to diverse effect on its mechanical and thermal p r operty. Lastly, antibacterial test showed that both 1.5 wt% CuNP and 3 wt% CuNP exhibited high effectivity on inhibiting Escherichia coli. Index terms: Copper Nanoparticle, Acrylonitrile Butadiene Styrene, filler, nanocomposite, antibacterial material, melt compounding, twin-screw extruder, Escherichia coli .

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Incorporation of nanoparticles in Polylactic Acid (PLA) for additive manufacturing is explored to alter the material property to suit its intended application. In this study, PLA is reinforced with multi-walled carbon nanotubes (MWCNT) using two-roll mill for fused deposition modeling (FDM) additive manufacturing. The chemical composition, thermal behavior, electrical, and antibacterial properties of the PLA/MWCNT nanocomposite were investigated. The Fourier transform infrared spectroscopy (FTIR) analysis showed the physical interaction of MWCNT to the PLA matrix. The x-ray diffraction analysis (XRD) data showed that increasing the MWCNT percentage increases the amorphous region and intensity, indicating the nucleating effect of MWCNT on PLA. Differential scanning calorimetry (DSC) analysis showed a decrease in the glass transition and melting temperatures compared to pure PLA by up to 9.36°C and 23.25°C, respectively, while introducing cold crystallization with the addition of MWCNT. The two point-probe resistance measurement showed a decreasing trend in the resistance of the composite which indicates an increase in conductivity as the the amount of MWCNT is increased. The analysis of disk diffusion test concluded that no bacterial growth of Escherichia coli and Staphylococcus aureus happened underneath the sample. Furthermore, the nanocomposite was successfuly extruded into a filament and test samples were 3D printed using FDM. The PLA/MWCNT produced are suitable for the production of a multifunctional filament with improved electrical, thermal and antimicrobial properties for different fused deposition modelling (FDM) additive manufacturing increasing the probable applications and competitiveness of this promising market niche.

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