International conference on Frontiers in Chemical Technology 2020 (FCT 2020)
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/21614
Browse
3 results
Search Results
Item The development of novel photodegradable linear low-density polyethylene (LLDPE) and investigation of the antibacterial properties(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Kandambi, D. P. H.; Mudiyanselage, T. Kuruwita; Udawatte, C. S.Plastic does not decompose easily under natural conditions and the need for degradable polyethylene has become an important area of research. In this study, the suitability of using cinnamaldehyde, in its natural and synthetic forms, and benzophenone, as photo oxidative sensitizers were evaluated. The results showed that oxidative degradation of linear low density polyethylene (LLDPE) increased significantly with the incorporation of these materials. Oxidative sensitization increased significantly with incorporation of natural cinnamaldehyde, Best results for oxidative sensitization were obtained by incorporation of 20% by mass natural cinnamaldehyde. The polymer composite films were prepared using a polymer solution in toluene and 2 cm x 2 cm films were caste between glass slides. 10 samples of each type were analyzed. The extent and nature of degradation was evaluated using FTIR spectroscopy, percentage weight loss and surface analysis techniques. The auto oxidative degradation of the composite films was carried out by accelerated UV initiated degradation, and also under natural rooftop conditions. Embrittlement and color development with aging in the photosensitizer incorporated polymer films were noticeably evident, when compared with the nonincorporated polymer films under similar conditions. Since polymer films are used for food and drug packing applications, antibacterial properties of the composite films were evaluated for four bacterial strains, Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853) and Bacillus cereus (ATCC 11778) using agar disc-diffusion method. Cinnamaldehyde containing composite films displayed significant antibacterial properties against all four bacterial strains, whereas benzophenone containing films did not show antibacterial properties against these strains.Item Development of a face and body cleanser using Cocos nucifera (coconut) oil, coconut shell charcoal and rice husk charcoal(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Jayasooriya, J. A. C. T.; Udawatte, C. S.Air pollutants and toxic elements can directly affect the skin as it is the outermost barrier protecting the body. In this study, a cleanser was formulated using charcoal, virgin coconut oil, and other local ingredients. An artificial sweat solution including NaCl, NH4Cl, acetic acid, lactic acid was treated with coconut shell charcoal (CSC) and rice husk charcoal (RHC) varying the particle size, dosage, and the contact time with the solution, in triplicates. The remaining organic acids, NH4 +, and Na+ were determined by formalin titrimetric method and flame photometry. CSC having the particle size of 0.25-0.50 mm exhibited higher adsorption towards the two main components in human perspiration; NaCl and NH4Cl than RHC, at an average contact time of 30 minutes. Therefore, CSC was used as the adsorbent. Virgin coconut oil was used as a moisturizer, an antioxidant, an emulsifying agent, sodium lauryl ether sulfate as the foaming agent and bee’s honey as the binding agent, a thickener, an antimicrobial and a humectant. Other ingredients used were kaolinite, sesame oil, and sweet orange essential oil. The pH of the product was 6; therefore, pH balanced. The product showed significant antibacterial activity against Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa when subjected to agar well diffusion method. The highest result was observed against Staphylococcus aureus, giving an inhibition zone of 2.5 cm for 100 mg of the product, while 5 μg of Ciprofloxacin showed an inhibition zone of 3.0 cm. The product was easily spreadable, washable, and had a thick consistency. Patch test was done by applying 400 mg of the product on the dorsal forearm of 10 volunteers with a diameter of 1 inch, for 30 minutes, then rinsed off with water. No adverse effects were exhibited. Therefore, this product can be considered safe, and it achieves the desired attribute as a cleanser.Item Removal of methylene blue from waste water using cinnamon wood.(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Wijesekara, D. N.; Udawatte, C. S.The presence of dyes in industrial effluents is a major cause of water pollution. Cinnamon (Cinnamomum verum) is native to Sri Lanka and is available in abundance. Cinnamon wood saw dust may be used as a low cost adsorbent with no processing, or with a simple, yet economical modification for enhanced adsorption. This study investigated the removal of Methylene Blue (MB) by non-modified (NMSD) and alkaline modified (MSD) saw dust from cinnamon wood. Batch adsorption experiments were carried out, and experiments were performed in triplicate along with a control without saw dust. Characterization via SEM and FTIR suggested that change in surface morphology and functional groups may account for the increase in adsorption capacity of MSD, which is fourfold higher than NMSD. The highest adsorption capacity observed for NMSD was 44.4 mg g-1, contact time was 90 min, at pH 6 with 0.1 g of NMSD, particle size range less than 0.15 mm, per 25.00 mL of 200 ppm MB solution. The adsorption data for NMSD fitted best with Toth model and insignificant variance with pH, and best fit pseudo first order model indicates physisorption to be dominant over chemisorption. The highest adsorption capacity for MSD was 119.6 mg g-1, contact time was 120 min for 0.1 g of MSD, less than 0.15 mm particle size range, for 25.00 mL of 350 ppm MB at pH 4. Redlich-Peterson isotherm and pseudo second order kinetic model was best for MSD with correlation coefficients greater than 0.99. Kinetic data suggests the possibility of liquid film diffusion being the rate determining step rather than intra-particle diffusion for both NMSD and MSD. The results demonstrate the potential use of cinnamon wood as a low cost adsorbent for MB, henceforth adding commercial value for cinnamon wood, which is otherwise used as firewood or discarded as waste.