Browsing by Author "Munaweera, I"

Now showing 1 - 3 of 3

item: Conference-Full-text
Deflourination of drinking water using layered double Hydroxides
(2013-11-19) Warsakoon, E; Gunawardene, N; Kalahe, H; Munaweera, I; Madusanka, N; Kottegoda, N
Safe drinking water is one of the prerequisites for a healthy life. In Sri Lanka 70% of the population satisfy their water needs from ground water and as a result majority of them suffer from water related problems. One of the pertaining problems prevailing in the dry zone of Sri Lanka is the presence of elevated levels of fluoride ions in drinking water leading to many health related problems. Many studies have been carried out to address the issue however little success has been reported up to date. This study focuses on suggesting a nanotechnology based solution to deflourinate drinking water in the dry zone, Sri Lanka, for domestic water tanks or as a region water purification solution. Layered double hydroxides (LDHs) which readily undergo anion exchange reactions have been used as a suitable candidate for deflourination. The study further concentrates on the regeneration of the material after removal of fluoride ions without releasing flouride ions back in to the water cycle.
item: Article-Full-text
A Novel green approach to synthesize curcuminoid-layered double hydroxide nanohybrids: Adroit biomaterials for future antimicrobial applications
(1270-9638, 2021) Madhusha, C; Rajapaksha, K; Munaweera, I; de Silva, M; Perera, C; Wijesinghe, G; Weerasekera, M; Attygalle, D; Sandaruwan, C
Thermal instability, photodegradation, and poor bioavailability of natural active ingredients are major drawbacks in developing effective natural product-based antimicrobial formulations. These inherited issues could be fruitfully mitigated by the introduction of natural active ingredients into various nanostructures. This study focuses on the development of a novel green mechanochemical synthetic route to incorporate curcuminoids into Mg-Al-layered double hydroxides. The developed one-pot and scalable synthetic approach makes lengthy synthesis procedures using toxic solvents redundant, leading to improved energy efficiency. The hydrotalcite-shaped nanohybrids consist of surface and interlayer curcuminoids that have formed weak bonds with layered double hydroxides as corroborated by X-ray diffractograms, X-ray photoelectron spectra, and Fourier transmission infrared spectra. The structural and morphological properties resulted in increased thermal stability of curcuminoids. Slow and sustained release of the curcuminoids was observed at pH 5.5 for a prolonged time up to 7 h. The developed nanohybrids exhibited zeroth-order kinetics, favoring transdermal application. Furthermore, the efficacy of curcuminoid incorporated LDHs (CC-LDH) as an anticolonization agent was investigated against four wound biofilm-forming pathogens, Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant Staphyloccocus aureus, and Candida albicans, using a broth dilution method and an in vitro biofilm model system. Microbiological studies revealed a 54−58% reduction in biofilm formation ability of bacterial pathogens in developed nanohybrids compared to pure curcuminoids. Therefore, the suitability of these green-chemically synthesized CC-LDH nanohybrids for next-generation antimicrobial applications with advanced dermatological/medical properties is well established.
item: Article-Full-text
Urea–hydroxyapatite-montmorillonite nanohybrid composites as slow release nitrogen compositions
(Elsevier, 2017) Madusanka, N; Sandaruwan, C; Kottegoda, N; Sirisena, D; Munaweera, I; De Alwis, A; Karunaratne, V; Amaratunga, GAJ
Nanohybrid composite was developed by the encapsulation of urea modified hydroxyapatite nanoparticles into the nanolayers of montmorillonite. The nanohybrid composites were synthesized by two approaches; solution phase synthesis and liquid assisted grinding techniques and were tested for their slow release nitrogen in soil. The characterization results revealed the successful realization of a nanohybrid containing urea modified hydroxyapatite nanoparticles encapsulated in montmorillonite. The release behavior of urea in different pH values indicated a slow and sustained release of nitrogen. The rate of release of N was significantly lower in the nanohybrid composite prepared using solvent assisted grinding techniques. Pot trials conducted using Oryza sativa (rice) demonstrated a significant yield enhancement with the novel plant nutrient system. Montmorillonite nanohybrid composite thus prepared can be used as an environmentally friendly fertilizer formulation which could be extended to solve one of the major problems faced in the global fertilization of low nitrogen use efficiency in agriculture.