Prof. Charitha Jayaruk Thambiliyagodage

Person:
Prof. Charitha Jayaruk Thambiliyagodage

ORCID

https://orcid.org/0000-0003-0906-4441

Google Scholar

https://scholar.google.com/citations?user=kdc5vsQAAAAJ

Name

Prof. Charitha Jayaruk Thambiliyagodage

Biography

Jayaruk is a graduate of the University of Colombo. He pursued his PhD in Chemistry from The University of Alabama, USA. He has specialized in Materials, Analytical and Physical Chemistry. Currently, he is working as an Assistant Professor at the Department of Applied Sciences, SLIIT. He is the coordinator of the BSc Biotechnology degree programme. He has been awarded the chartered chemist designation by the Institute of Chemistry, Ceylon. He supervises Postgraduate students at the University of Colombo and the University of Kelaniya and supervises undergraduate students at the Institute of Chemistry. He is interested in doing research on using nanomaterials in water purification and as antimicrobial reagents. Further, he is interested in researching on algae and plant materials for their pharmaceutical and cosmeceutical activities. He has specialized in many instruments like Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD), X-Ray Photoelectron Spectrometer (XPS), Gas chromatograph-Mass spectrometer (GC-MS), Raman Spectrometer, FT-IR spectrometer, UV-Visible Spectrophotometer, Brunauer-Emmett-Teller (BET) surface area analyzer etc. He is interested in practical-based science education and believes in uplifting the research culture among upcoming scientists in the country.

Research Interests

Application of nanomaterials for water purification Novel nanomaterials incorporated cosmeceuticals and pharmaceuticals Natural material based neutraceuticals Alternative energy sources Novel packaging materials Environmental Chemistry

Organizational Units

Organizational Unit

Faculty of Humanities & Sciences

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Now showing 1 - 10 of 20

Open Access
Influence of Laboratory Synthesized Graphene Oxide on the Morphology and Properties of Cement Mortar
(MDPI, 2023-01) Ganesh, S; Thambiliyagodage, C; Perera, S. V. T. J; Rajapakse, R.K.N.D
The introduction of Graphene Oxide (GO), a nanomaterial, has shown considerable promise in improving the mechanical properties of cement composites. However, the reasons for this improvement are not yet fully understood and demand further research. This study aims to understand the effect of laboratory-produced GO, using Tour’s method, on the mechanical properties and morphology of cement mortar containing GO. The GO was characterized using Fourier-transform infrared spectroscopy, X-ray Photoelectron Spectroscopy (XRD), X-ray powder diffraction, and Raman spectroscopy alongside Scanning electron microscopy (SEM). This study adopted a cement mortar with GO percentages of 0.02, 0.025, 0.03, 0.035, and 0.04 with respect to the weight of the cement. The presence of GO in cement mortar increased the density and decreased the consistency and setting times. At the optimum of 0.03% GO viscous suspension, the mechanical properties such as the 28-day compressive strength, splitting tensile strength, and flexural strength were enhanced by 41%, 83%, and 43%, respectively. In addition, Brunauer–Emmett–Teller analysis indicates an increase in surface area and volume of micropores of GO cement mortar, resulting in a decreased volume of mesopores. The improvement in properties was due to increased nucleation sites, calcium silicate hydrate (CSH) density, and a decreased volume of mesopores.
Open Access
Fabrication of r-GO/GO/α-Fe2O3/Fe2TiO5 Nanocomposite Using Natural Ilmenite and Graphite for Efficient Photocatalysis in Visible Light
(MDPI, 2023-01) Usgodaarachchi, L; Jayanetti, M; Thambiliyagodage, C; Liyanaarachchi, H; Vigneswaran, S
Hematite (α-Fe2O3) and pseudobrookite (Fe2TiO5) suffer from poor charge transport and a high recombination effect under visible light irradiation. This study investigates the design and production of a 2D graphene-like r-GO/GO coupled α-Fe2O3/Fe2TiO5 heterojunction composite with better charge separation. It uses a simple sonochemical and hydrothermal approach followed by L-ascorbic acid chemical reduction pathway. The advantageous band offset of the α-Fe2O3/Fe2TiO5 (TF) nanocomposite between α-Fe2O3 and Fe2TiO5 forms a Type-II heterojunction at the Fe2O3/Fe2TiO5 interface, which efficiently promotes electron-hole separation. Importantly, very corrosive acid leachate resulting from the hydrochloric acid leaching of ilmenite sand, was successfully exploited to fabricate α-Fe2O3/Fe2TiO5 heterojunction. In this paper, a straightforward synthesis strategy was employed to create 2D graphene-like reduced graphene oxide (r-GO) from Ceylon graphite. The two-step process comprises oxidation of graphite to graphene oxide (GO) using the improved Hummer’s method, followed by controlled reduction of GO to r-GO using L-ascorbic acid. Before the reduction of GO to the r-GO, the surface of TF heterojunction was coupled with GO and was allowed for the controlled L-ascorbic acid reduction to yield r-GO/GO/α-Fe2O3/Fe2TiO5 nanocomposite. Under visible light illumination, the photocatalytic performance of the 30% GO/TF loaded composite material greatly improved (1240 Wcm−2). Field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) examined the morphological characteristics of fabricated composites. X-ray photoelectron spectroscopy (XPS), Raman, X-ray diffraction (XRD), X-ray fluorescence (XRF), and diffuse reflectance spectroscopy (DRS) served to analyze the structural features of the produced composites. © 2022 by the authors.
Open Access
Kinetics and Thermodynamics Study of Methylene Blue Adsorption to Sucrose- and Urea-Derived Nitrogen-Enriched, Hierarchically Porous Carbon Activated by KOH and H3PO4
(American Chemical Society, 2023-04-27) Liyanaarachchi, H; Thambiliyagodage, C; Lokuge, H; Vigneswaran, S
Hierarchically porous nitrogen-enriched carbon materials synthesized by polymerization of sucrose and urea (SU) were activated by KOH and H3PO4 (SU-KOH and SU-H3PO4, respectively). Characterization was undertaken and the synthesized materials were tested for their ability to adsorb methylene blue (MB). Scanning electron microscopic images along with the Brunauer−Emmett−Teller (BET) surface area analysis revealed the presence of a hierarchically porous system. X-ray photoelectron spectroscopy (XPS) confirms the surface oxidation of SU upon activation with KOH and H3PO4. The best conditions for removing dyes utilizing both activated adsorbents were determined by varying the pH, contact time, adsorbent dosage, and dye concentration. Adsorption kinetics were evaluated, and the adsorption of MB followed second-order kinetics, suggesting the chemisorption of MB to both SU-KOH and SUH3PO4. Times taken to reach the equilibrium by SU-KOH and SU-H3PO4 were 180 and 30 min, respectively. The adsorption isotherm data were fitted to the Langmuir, Freundlich, Temkin, and Dubinin models. Data were best described by the Temkin isotherm model for SU-KOH and the Freundlich isotherm model for SU-H3PO4. Thermodynamics of the adsorption of MB to the adsorbent was determined by varying the temperature in the range of 25−55 °C. Adsorption of MB increased with increasing temperature, suggesting that the adsorption process is endothermic. The highest adsorption capacities of SU-KOH and SU-H3PO4 (1268 and 897 mg g−1 , respectively) were obtained at 55 °C. Synthesized adsorbents were effective in removing MB for five cycles with some loss in activity. The results of this study show that SU activated by KOH and H3PO4 are environmentally benign, favorable, and effective adsorbents for MB adsorption.
Open Access
Antibacterial Activity of Zn Decorated TiO2 Nanocomposites
(Faculty of Humanities and Sciences, SLIIT, 2023-11-01) Kumarasinghe, N.M.A,; Thambiliyagodage, C; Jayanetti, M; Liyanaarachchi, H
Bacterial infections have a significant public health impact. Infections are caused by bacteria in animals, plants as well as humans. Pathogenic bacteria can produce toxins, which are chemical poisons that interfere with cell function such as digestion of normal human enzymes, evasion of infection-fighting white blood cells, and immune clearance. Antibiotic prophylaxis is used to prevent bacterial infection. Antibiotic resistance is one of the most serious concerns in world health. Antibacterial nanoparticles are one possible answer to antimicrobial resistance. These nanomaterials not only kill antibiotic-resistant bacteria through various modes of action but, they can also be employed in conjunction with existing clinically relevant antibiotics to help overcome antimicrobial resistance mechanisms. In this study, anodized titanium dioxide (TiO2) nanorods were treated hydrothermally with zinc oxide (ZnO) nanoparticles to give titanium (Ti) antibacterial properties. The antibacterial activity of synthesized samples was investigated by Agar Well Diffusion method at 40 mg/ml concentration, against gram negative Klebsiella pneumoniae. To determine the antibacterial activity, the diameter of the zone of inhibition was measured, and the resulting data were statistically analyzed. Zn/TiO2 nano particles were characterized by using X-ray diffraction (XRD) Analysis.
Embargo
Synthesis of Amine Functionalized Silica- Cu4O3 Adsorbent from Rice Husk for Efficient Removal of Crystal Violet from Aqueous Solution
(Faculty of Humanities and Sciences,SLIIT, 2021-09-25) Usgodaarachchi, L.; Thambiliyagodage, C; Angappan, S
Silica based Nano adsorbent (SCN) synthesized using rice husk as the raw material via sol- gel pathway. Silica nanoparticles were successfully functionalized with 3-aminopropyl triethoxysilane (APTES) via in-situ functionalization method. Synthesized nanoparticles were characterized by XRD and FT-IR. The equilibrium adsorption capacity of 0.02g of SCN to adsorb 10 mg/L crystal violet (CV) was 20.09 mg/g. The influence of pH, adsorbent dosage, and initial CV concentration on adsorption of CV to SCN were studied. The equilibrium data for CV adsorption on SCN well fitted to Freundlich model, with a Freundlich adsorption capacity of 8.23 mg g-1. The adsorption of CV could be best described by the pseudosecond order model with 0.99 linier regression coefficient.
Embargo
Assessing the Efficacy of Machine Learning Algorithms in Predicting Critical Properties of Gold Nanoparticles for Pharmaceutical Applications
(Springer Nature Link, 2025-07-08) Fernando, H; Mohottala, S; Jayanetti, M; Thambiliyagodage, C
Au nanoparticles are increasingly used in pharmaceuticals, but their synthesis is costly and time-intensive. Machine Learning can help optimize this process. In this research, eight distinct Machine Learning models were implemented and optimized on a dataset comprising 3000 records of gold nanoparticles. The performance of these models was assessed using four accuracy metrics and the time required for training and inference. The results are promising, with all seven models demonstrating high accuracy and low time requirements. Notably, the XGBoost and Artificial Neural Network models exhibited exceptional performance, with Mean Squared Error values of 0.0235 and 0.0098, Mean Absolute Error values of 0.1021 and 0.0674, Mean Absolute Percentage Deviation values of 0.4945 and 0.3590, R2 scores of 0.9995 and 0.9998, and inference times of 0.0029 and 0.4299 s, respectively. The Explainable Artificial Intelligence analysis of the resulting models revealed some interesting insights into how the models make the predictions and what factors heavily contribute to the nanoparticle AVG_R, allowing chemists to optimize the synthesis for gold nanoparticles better. The key contributions of the research include the design and development of eight Machine Learning models using industry-standard frameworks, the training, tuning, and evaluation of these eight models using five different metrics, and further assessment of these trained models using Explainable Artificial Intelligence. The findings indicate a substantial potential for applying neural networks in the design phase of nanoparticle synthesis, which could lead to significant reductions in both the time and cost required for synthesizing Au nanoparticles for pharmaceutical applications.
Open Access
Recent Advances in Chitosan-Based Applications—A Review
(MDPI, 2023-03-03) Thambiliyagodage, C; Jayanetti, M; Mendis, A; Ekanayake, G; Liyanaarachchi, H; Liyanaarachchi, S
Chitosan derived from chitin has gathered much interest as a biopolymer due to its known and possible broad applications. Chitin is a nitrogen-enriched polymer abundantly present in the exoskeletons of arthropods, cell walls of fungi, green algae, and microorganisms, radulae and beaks of molluscs and cephalopods, etc. Chitosan is a promising candidate for a wide variety of applications due to its macromolecular structure and its unique biological and physiological properties, including solubility, biocompatibility, biodegradability, and reactivity. Chitosan and its derivatives have been known to be applicable in medicine, pharmaceuticals, food, cosmetics, agriculture, the textile and paper industries, the energy industry, and industrial sustainability. More specifically, their use in drug delivery, dentistry, ophthalmology, wound dressing, cell encapsulation, bioimaging, tissue engineering, food packaging, gelling and coating, food additives and preservatives, active biopolymeric nanofilms, nutraceuticals, skin and hair care, preventing abiotic stress in flora, increasing water availability in plants, controlled release fertilizers, dye-sensitised solar cells, wastewater and sludge treatment, and metal extraction. The merits and demerits associated with the use of chitosan derivatives in the above applications are elucidated, and finally, the key challenges and future perspectives are discussed in detail.
Open Access
Antibacterial Activity of Cu Decorated TiO2 Nanorods
(Faculty of Humanities and Sciences, SLIIT, 2023-11-01) Nilaweera, G; Thambiliyagodage, C; Jayanetti, M; Liyanaarachchi, H
Global public health is seriously threatened by the spread of infectious illnesses in general, particularly by the appearance of bacterial strains that are resistant to antibiotics. New antibacterial drugs are likely a result of recent developments in the field of nanobiotechnologies, particularly the ability to make metal oxide nanomaterials with specific morphologies. Using antibiotics for a long time period will show antibiotic resistance in host cells, which means the drug does not kill the pathogen anymore. As a solution to this problem, nanoparticles can be used. Researchers may find nanoparticles with high antibacterial activity which can kill the pathogen. This research shows the antibacterial activity of Cu decorated TiO2 nanoparticles against Klebsiella pneumoniae. In here the nanoparticles were synthesized in three weight ratios with TiO2 and CuO using hydrothermal method. Pure CuO and TiO2 were synthesized as controls. Then antibacterial activity was checked by the well diffusion method. After incubation the inhibition zones were measured, and the results were recorded. The antibacterial effect can be determined with the size of the inhibition zone. The synthesized nanoparticles were characterized using XRD to analyze physical properties such as phase composition, crystal structure. The value for inhibition zone of the best performing sample which the sample concentration is 40mg/ml is 13.17±1.53 mm which contains TiO2 : CuO (1:2) weight ratio. Therefore it can be determined that the best performing sample which has the highest antibacterial activity against Klebsiella pneumoniae is G3 which contains TiO2 : CuO (1:2) weight ratio.
Open Access
Fabrication of TiO2 Spheres and a Visible Light Active α‑Fe2O3/ TiO2‑Rutile/TiO2‑Anatase Heterogeneous Photocatalyst from Natural Ilmenite
(researchgate.net, 2022-07-26) Usgodaarachchi, L; Thambiliyagodage, C; Wijesekera, R; Vigneswaran, S; Kandanapitiye, M
High-purity (98.8%, TiO2) rutile nanoparticles were successfully synthesized using ilmenite sand as the initial titanium source. This novel synthesis method was cost-effective and straightforward due to the absence of the traditional gravity, magnetic, electrostatic separation, ball milling, and smelting processes. Synthesized TiO2 nanoparticles were 99% pure. Also, highly corrosive environmentally hazardous acid leachate generated during the leaching process of ilmenite sand was effectively converted into a highly efficient visible light active photocatalyst. The prepared photocatalyst system consists of anatase-TiO2/rutile-TiO2/Fe2O3 (TF-800), rutile-TiO2/Fe2TiO5 (TFTO-800), and anatase-TiO2/Fe3O4 (TF-450) nanocomposites, respectively. The pseudo-second-order adsorption rate of the TF-800 ternary nanocomposite was 0.126 g mg–1 min–1 in dark conditions, and a 0.044 min–1 visible light initial photodegradation rate was exhibited. The TFTO-800 binary nanocomposite adsorbed methylene blue (MB) following pseudo-second-order adsorption (0.224 g mg–1 min–1) in the dark, and the rate constant for photodegradation of MB in visible light was 0.006 min–1. The prepared TF-450 nanocomposite did not display excellent adsorptive and photocatalytic performances throughout the experiment period. The synthesized TF-800 and TFTO-800 were able to degrade 93.1 and 49.8% of a 100 mL, 10 ppm MB dye solution within 180 min, respectively.
Open Access
Persulfate assisted photocatalytic and antibacterial activity of TiO2–CuO coupled with graphene oxide and reduced graphene oxide
(https://www.nature.com, 2024-05-31) Thambiliyagodage, C; Liyanaarachchi, H; Jayanetti, M; Ekanayake, G; Mendis, A; Samarakoon, U; Vigneswaran, S
Photocatalysts of TiO2–CuO coupled with 30% graphene oxide (GO) were hydrothermally fabricated, which varied the TiO2 to CuO weight ratios to 1:4, 1:2, 1:1, 2:1 and 4:1 and reduced to form TiO2–CuO/reduced graphene oxide (rGO) photocatalysts. They were characterized using XRD, TEM, SEM, XPS, Raman, and DRS technologies. TiO2–CuO composites and TiO2–CuO/GO degrade methylene blue when persulfate ions are present. Persulfate concentration ranged from 1, 2, 4 to 8 mmol/dm−3 in which the highest activity of 4.4 × 10–2 and 7.35 × 10–2 min−1 was obtained with 4 mmol/dm−3 for TiO2–CuO (1:4) and TiO2–CuO/GO (1:1), respectively. The presence of EDTA and isopropyl alcohol reduced the photodegradation. TiO2–CuO coupled with rGO coagulates methylene blue in the presence of persulfate ions and such coagulation is independent of light. The catalyst dosage and the concentration of the dye were varied for the best-performing samples. The antibacterial activity of the synthesized samples was evaluated against the growth of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumonia. Ti:Cu (1:2)-GO and Ti:Cu (1:4)-GO had the highest antibacterial activity against K. pneumoniae (16.08 ± 0.14 mm), P. aeruginosa (22.33 ± 0.58 mm), E. coli (16.17 ± 0.29 mm) and S. aureus (16.08 ± 0.88).