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

Full item page

Search Results

Now showing 1 - 10 of 12

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
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.
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
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).
Open Access
A Study on Conscinium fenestratum and Chitosan Biopolymer Composite for Ayurvedic Drug Delivery
(Faculty of Humanities and Sciences, SLIIT, 2024-12-04) Alwis, M; Jayanetti, M; Thambiliyagodage, C
This study delves into the synergisti c amalgamati on of Coscinium fenestratum, an Ayurvedic medicinal plant, and chitosan biopolymer. This results in the innovati ve Venivel Chitosan Composite, which has established a pioneering drug delivery system. Subsequently, the composite material, Venivel Chitosan Composite, was formulated by integrati ng Coscinium fenestratum extract and chitosan biopolymer. Structural characteristi cs of Chitosan biopolymer and Venivel Chitosan Composite were determined via scanning electron microscopy (SEM), off ering valuable insights into their morphological features. Furthermore, a comprehensive characterizati on of the composite was achieved through the analysis of X-ray diff racti on (XRD) patt erns, elucidati ng its crystalline structure. A meti culous examinati on of the in vitro drug release profi le revealed a predominant diff usion mechanism, indicati ng the potenti al suitability of this system for applicati ons in wound healing treatments. In conclusion, integrati ng Coscinium fenestratum with chitosan biopolymer presents a versati le composite with promising anti bacterial, anti oxidant, and anti - infl ammatory properti es, elevati ng its potenti al for targeted and controlled ayurvedic drug delivery applicati ons.
Embargo
Kinetic study of in vitro release of curcumin from chitosan biopolymer and the evaluation of biological efficacy
(Elsevier B.V., 2024-09) Wijayawardana, S; Thambiliyagodage, C; Jayanetti, M
Sustained release of curcumin from the polymeric carrier system chitosan, a natural biopolymer material derived from chitin originated from natural shrimp shell waste, was studied. Six kinetic models, zero order, first order, Korsmeyer–Peppas (KP), Peppas – Sahlin (PS), Higuchi, and Hixson–Crowell, were applied to study the drug release kinetics. The release mechanism of the drug from the curcumin-chitosan composite was evaluated by changing the pH, ionic strength of the release media, and drug concentration. KP and PS models were selected among the studied models to investigate the drug release mechanism from the chitosan biopolymer based on the R2 values (R2 > 0.99). The model constants m in the PS model and n in the KP model stand for the case II relaxation and Fickian diffusion contribution, respectively. The n being < 0.43 in the KP model suggests that the Fickian diffusion governs the drug release. Furthermore, there is a noticeable difference between the values obtained for model parameters m and n in the PS and KP models, indicating that Case II relaxation and Fickian diffusion play crucial roles in the curcumin release mechanism from chitosan. Polymer relaxation has been proven to play a predominant role in releasing curcumin from the composite at lower ionic strengths and higher pH values. Anti-inflammatory activity was tested using the egg-albumin denaturation assay, and the diphenyl-2-picrylhydrazyl assay was carried out to determine the antioxidant activity of the composite. The composite material showed IC50 values of 0.29 mg/ mL and 1.08 mg/ mL for anti-inflammatory and anti-oxidant activities, respectively. The drug composite has shown antibacterial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus, which are highly effective against S.aureus. The resulting inhibition zones for S.aureus were 13.34 ± 0.34 mm, 16.34 ± 0.60 mm, and 13.34 ± 0.73 mm for 5, 10, and 20 mg/ml concentrations, respectively. The drug composite’s minimum inhibitory concentration/ minimum bactericidal concentration ratio for S.aureus, K. pneumoniae, and P.aeruginosa was greater than 4, suggesting that they cause bacteriostatic effects.
Open Access
In vitro influence of PEG functionalized ZnO–CuO nanocomposites on bacterial growth
(PubMed ID, 2024-01-14) Thambiliyagodage, C; Jayanetti, M; Liyanaarachchi, H; Ekanayake, G; Mendis, M; Usgodaarachchi, L
Polyethyleneglycol-coated biocompatible CuO–ZnO nanocomposites were fabricated hydrothermally varying Zn:Cu ratios as 1:1, 2:1, and 1:2, and their antibacterial activity was determined through the well diffusion method against the Gram-negative Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and the Gram-positive Staphylococcus aureus. The minimum inhibitory concentration and the minimum bactericidal concentration values of the synthesized samples were determined. Subsequently, the time synergy kill assay was performed to elucidate the nature of the overall inhibitory effect against the aforementioned bacterial species. The mean zone of inhibition values for all four samples are presented. The inhibitory effect increased with increasing concentration of the nanocomposite (20, 40 and 60 mg/ml) on all the bacterial species except for S. aureus. According to the MBC/MIC ratio, ZnO was found to be bacteriostatic for E. coli and P. aeruginosa, and bactericidal for S. aureus and K. pneumoniae. Zn:Cu 2:1 was bactericidal on all bacterial species. A bacteriostatic effect was observed on E. coli and P. aeruginosa in the presence of Zn:Cu 1:1 whereas, it showed a bactericidal effect on S. aureus and K. pneumoniae. Zn:Cu 1:2 exhibited a bacteriostatic effect on E. coli while a bactericidal effect was observed for E. coli, P. aeruginosa, and K. pneumoniae. The metal oxide nanocomposites were found to be more sensitive towards the Gram-positive strain than the Gram-negative strains. Further, all the nanocomposites possess anti-oxidant activity as shown by the DPPH assay.
Open Access
Fabrication of dual Z-scheme g-C3N4/Fe2TiO5/Fe2O3 ternary nanocomposite using natural ilmenite for efficient photocatalysis and photosterilization under visible light
(Elsevier, 2022-11-11) Thambiliyagodage, C; Liyanaarachchi, H; Kumar, A; Jayanetti, M; Usgodaarachchi, L; Lansakara, B
The advanced oxidation process is a prominent method available to remove dyes released to normal water reservoirs to alleviate water scarcity. We report the fabrication of novel g-C3N4/Fe2TiO5/Fe2O3 using natural ilmenite sand as the precursor of the metallic semi-conductors exploration of a heterostructure for photodegradation of methylene blue under sunlight. Ternary composites were synthesized by varying g-C3N4 with respect to Fe2TiO5/Fe2O3 and varying Fe2TiO5/Fe2O3 with respect to g-C3N4 where the varying component was varied as 8, 24 and 40%, respect to the constant material. The hybridization of the three semi-conductors has been confirmed by the microscopic, chemical, and structural analyses. X-ray diffraction patterns show the presence of all three g-C3N4, Fe2TiO5 and α-Fe2O3 while the transmission electronic microscopic and scanning electronic microscopic images show the heterogeneous distribution of the metal oxide nanoparticles on g-C3N4 matrix forming the composite. HRTEM images further reveal the junction of Fe2TiO5 and α-Fe2O3. X-ray photoelectron spectra show the existence of s-triazine and heptazine rings in the composites with Fe3+ and Ti4+ as the only oxidation states of Fe and Ti. Fe2TiO5/Fe2O3/40% g-C3N4 with bandgap of 2.63 eV calculated by diffuse reflectance UV-Visible spectroscopy showed the highest photocatalytic activity (0.009 min−1) being 1.3 times greater than the Fe2TiO5/Fe2O3 nanoparticles. Enhanced photocatalytic activity over the fabricated composites was observed due to the increased visible light absorption, efficient charge separation and improved charge transportation. g-C3N4 coupled with 40% Fe2TiO5/Fe2O3 showed the highest antibacterial activity against gram-negative E.Coli. The synthesis of dual Z-scheme g-C3N4/Fe2TiO5/Fe2O3 ternary composite provides new sights in developing novel photocatalysts using natural ilmenite sand for environmental applications.
Open Access
Efficient Visible-Light Photocatalysis and Antibacterial Activity of TiO2-Fe3C-Fe-Fe3O4/Graphitic Carbon Composites Fabricated by Catalytic Graphitization of Sucrose Using Natural Ilmenite
(American Chemical Society, 2022-07-26) Thambiliyagodage, C; Usgodaarachchi, L; Jayanetti, M; Liyanaarachchi, C; Kandanapitiye, M; Vigneswaran, S
Dyes in wastewater are a serious problem that needs to be resolved. Adsorption coupled photocatalysis is an innovative technique used to remove dyes from contaminated water. Novel composites of TiO2-Fe3C-Fe-Fe3O4dispersed on graphitic carbon were fabricated using natural ilmenite sand as the source of iron and titanium, and sucrose as the carbon source, which were available at no cost. Synthesized composites were characterized by X-ray diffractometry (XRD), Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), and diffuse reflectance UV-visible spectroscopy (DRS). Arrangement of nanoribbons of graphitic carbon with respect to the nanomaterials was observed in TEM images, revealing the occurrence of catalytic graphitization. Variations in the intensity ratio (ID/IG), Laand LD, calculated from data obtained from Raman spectroscopy suggested that the level of graphitization increased with an increased loading of the catalysts. SEM images show the immobilization of nanoplate microballs and nanoparticles on the graphitic carbon matrix. The catalyst surface consists of Fe3+and Ti4+as the metal species, with V, Mn, and Zr being the main impurities. According to DRS spectra, the synthesized composites absorb light in the visible region efficiently. Fabricated composites effectively adsorb methylene blue via π-πinteractions, with the absorption capacities ranging from 21.18 to 45.87 mg/g. They were effective in photodegrading methylene blue under sunlight, where the rate constants varied in the 0.003-0.007 min-1range. Photogenerated electrons produced by photocatalysts captured by graphitic carbon produce O2•-radicals, while holes generate OH•radicals, which effectively degrade methylene blue molecules. TiO2-Fe3C-Fe-Fe3O4/graphitic carbon composites inhibited the growth of Escherichia coli (69%) and Staphylococcus aureus (92%) under visible light. Synthesized novel composites using natural materials comprise an ecofriendly, cost-effective solution to remove dyes, and they were effective in inhibiting the growth of Gram-negative and Gram-positive bacteria.