Browsing by Author "Sitinamaluwa, H. S."

Now showing 1 - 3 of 3

item: Conference-Abstract
GO-PES Membrane for industrial dye effluent water purification
(Department of Materials Science and Engineering, University of Moratuwa, 2024) Gamage, K. G. N.; Athapaththu, A. M. S. S.; Sitinamaluwa, H. S.; Sivahar, V.
Clean water scarcity is a major global issue, posing significant challenges for both the environment and human health. A major concern in industrial wastewater management is the presence of elevated concentrations of dyes in water systems. Graphene-based nanomaterial membranes offer a proactive solution, effectively removing industrial dye contaminants from water. The intrinsic two-dimensional structural attributes and remarkable properties exhibited by graphene and graphene oxide (GO) provide opportunities for their integration into nanoporous materials. When combined, these materials offer modifiable characteristics, enabling fine-tuning for enhanced efficacy in water filtration applications. Utilizing a pressure-assisted technique, synthesized GO-PES (GO-Polyether Sulfone) nanoporous membranes demonstrate heightened efficacy in the removal of Methylene Blue (MB) and Methyl Orange (MO), excelling particularly in key parameters such as membrane selectivity and permeation flux. In this study, industrial dye filtration membranes were synthesized using four different concentrations of graphene oxide (GO) to modulate the amount of GO incorporated. The results reveal notable trends: for MB, selectivity increased from 65.1% to 72.4% as GO concentration rose, while flux decreased from 0.03332 to 0.01806 m3/m2s. Similarly, for MO, selectivity increased from 47.9% to 72%, with flux decreasing from 0.02968 to 0.01851 m3/m2s.
item: Conference-Abstract
Graphene oxide-based nanofluid for heat transfer applications
(Department of Materials Science and Engineering, University of Moratuwa, 2024) Arachchi, M. D. P.; Sandaru, D. M. C.; Rajapaksha, S. M.; Abeygunewardane, A. A. G. A.; Sitinamaluwa, H. S.; Sivahar, V.
This research investigates the performance of Graphene Oxide-Deionized Water (GO-DI water) nanofluid, and partially reduced Graphene Oxide-Deionized water (prGODI water) nanofluid for enhanced heat transfer efficiency. GO and prGO were derived from Sri Lankan graphite via the modified hummers method followed by thermal reduction in a tube furnace. The effect of particle loading was analyzed on the viscosity, thermal conductivity (TC) and stability of nanofluid. The results show that the nanofluids beyond mass loading of 0.5 wt% of GO/prGO show poor stability. prGO was found to be more effective in enhancing the TC of the nanofluid, due to the enhanced TC of the prGO particles. TC enhancement of nanofluids up to 30% was achieved, with the highest increment shown by the nanofluid with 0.75 wt% prGO. Furthermore, the thermal transport characteristics of the nanofluids were computationally modelled using finite element analysis. The average convection heat transfer coefficient (CHC) of 0.5 wt% prGO-based nanofluid showed a 52% increment, highlighting the effectiveness of prGO-based nanofluids. Importantly, the nanofluids with particle concentrations below 0.5 wt% show performance enhancement ratio (PER) values suitable for practical applications. The outcome of this research shows the potential of GO-based nanofluids as state-of-the-art heat transfer fluids to be used in the coolant industry.
item: Conference-Abstract
TiO2 Nanotube arrays for sensing applications
(Department of Materials Science and Engineering, University of Moratuwa, 2024) Wijendra, W. A. S. N.; Sitinamaluwa, H. S.; Sivahar, V.
Titanium dioxide (TiO2) nanotubes have emerged as promising materials for gas sensing applications due to their high surface area and unique electronic properties. However, optimizing their synthesis for enhanced sensitivity remains a challenge. In this study, TiO2 nanotubes were synthesized for use as an efficient gas sensing material for detecting ethanol by anodizing pure titanium (Ti) thin (~0.5 mm) foil pieces at varying voltages (60V, 70V, 80V). The structural characteristics of the synthesized TiO2 nanotube arrays were analyzed using Scanning Electron Microscopy (SEM), revealing a variation in tube diameters from approximately 60 nm to 90 nm depending on anodization time (1 hour and 2 hours). The sample anodized for 2 hours at 60V and subsequently annealed at 450°C for 1.5 hours demonstrated a tube length of approximately 6 μm. Furthermore, this study details the design of the gas sensor circuit, the ethanol sensing chamber, and an Arduino-based temperature control system. The gas sensing performance of the TiO2 nanotube-based sensor was evaluated under exposure to 1000 ppm ethanol, demonstrating the potential of this material for efficient alcohol detection