Asmida Ismail

Partial Characterisation and Colorimetric Characteristics of Sargassum sp. Colorant on Treated Polyester Fabric with Dendrimer

This study focuses on the characterization of pigment compounds presence in Sargassum sp. extracts. The ground powder of dry Sargassum sp. was macerated in in methanol solution at 60°C for 48 hours in an aluminium foil-wrapped conical flask (to provide the dark environment). The extracted colourant was measured with UV-vis Spectrophotometer and Q-TOF LCMS to determine the compounds presence. The extracted colourant also used to dye pretreated and untreated polyester fabric with poly(amidoamine) dendrimer at different concentrations with and without mordants. The exhaustion dyeing with the simultaneous mordanting procedure was carried at 85°C for 60 minutes. The colorimetric properties of the dyed fabrics were then analysed. The results showed that the pigment compounds presence in Sargassum sp. extracts is fucoxanthin and chlorophyll. The application of dendrimer improved K/S values of the dyed fabric. Thus, Sargassum sp. extract is suitable to be used as natural dyes for textile dyeing.

Epiphytic Terrestrial Algae (Trebouxia sp.) as a Biomarker Using the Free-Air-Carbon Dioxide-Enrichment (FACE) System

The increasing concentration of CO2 in the atmosphere has caused significant environmental changes, particularly to the lower plants such as terrestrial algae and lichens that alter species composition, and therefore can contribute to changes in community landscape. A study to understand how increased CO2 in the atmosphere will affect algal density with minimal adjustment on its natural ecosystem, and the suitability of the algae to be considered as a biomarker, has been conducted. The current work was conducted in the Free-Air-Carbon Dioxide-Enrichment (FACE) system located in Universiti Kebangsaan Malaysia, Bangi, Malaysia. CO2 was injected through special valves located along the ring surrounding specimen trees where 10 × 10 cm quadrats were placed. A total of 16 quadrats were randomly placed on the bark of 16 trees located inside the FACE system. This system will allow data collection on the effect of increased CO2 without interfering or changing other parameters of the surrounding environment such as the wind speed, wind direction, humidity, and temperature. The initial density Trebouxia sp. was pre-determined on 1 March 2015, and the final density was taken slightly over a year later, on 15 March 2016. The exposure period of 380 days shed some light in understanding the effect of CO2 on these non-complex, short life cycle lower plants. The results from this research work showed that the density of algae is significantly higher after 380 days exposure to the CO2-enriched environment, at 408.5 ± 38.5 × 104 cells/cm2, compared to the control site at 176.5 ± 6.9 × 104 cells/cm2 (independent t-test, p < 0.001). The distance between the trees and the injector valves is negatively correlated. Quadrats located in the center of the circular ring recorded lower algal density compared to the ones closer to the CO2 injector. Quadrat 16, which was nearing the end of the CO2 valve injector, showed an exceptionally high algal density—2-fold higher than the average density at 796 ± 38.5 × 104 cells/cm2. In contrast, Quadrat 9, which was located in the center of the ring (lower CO2 concentration), recorded only 277 ± 38.5 × 104 cells/cm2, which further supports the previous claim. Based on the data obtained, this study provides useful data in understanding the positive effect of CO2 on algal density, in a natural environment, and suggests the use of epiphytic terrestrial algae as a biomarker.

Seaweed temporal distribution in southeast coast of Peninsular Malaysia and isolation of endophytic fungi

Temporal study of seaweeds was carried out between on February 2015 and November 2015 at Kampung Jawa Darat and Kampung Sungai Buntu at Pengerang, Johor, Malaysia. The research objectives were to study the diversity of seaweed and to determine the presence of fungal endophyte in the seaweed. The diversity of seaweed in the sampling site was calculated by using quadrat with 25 meter line transect by 3 replication for each site. The specimen were identified and processed in laboratory and kept for reference in the Algae Herbarium, Universiti Kebangsaan Malaysia. The specimen for fungal endophyte isolation was collected randomly by choosing the complete thallus, transferred into sterile zip-lock plastic bag and kept in freezer until used. From this study, a total of 29 species have been successfully identified including 12 species of Chlorophyta, 2 species of Phaeophyta and 14 species of Rhodophyta. From February to November 2015, the number of species highly varied and a significant change in community structure was noted. Kampung Sungai Buntu shows the highest diversity throughout the study compared to Kampung Jawa Darat. Eighteen seaweed species were screened for the presence of fungal endophyte, Sargassum polycystum shows the highest number of fungal endophyte. This study documented the seaweed diversity in two sites at Pengerang, Johor that accommodates fungal endophytes.

Electrical properties of Mg doped ZnO nanostructure annealed at different temperature

In this work, ZincOxide (ZnO) nanostructures doped with Mg were successfully grown on the glass substrate. Magnesium (Mg) metal element was added in the ZnO host which acts as a doping agent. Different temperature in range of 250°C to 500°C was used in order to investigate the effect of annealing temperature of ZnO thin films. Field Emission Scanning Electron Microscopy (FESEM) was used to investigate the physical characteristic of ZnO thin films. FESEM results have revealed that ZnO nanorods were grown vertically aligned. The structural properties were determined by using X-Ray Diffraction (XRD) analysis. XRD results showed Mg doped ZnO thin have highest crystalinnity at 500°C annealing temperature. The electrical properties were investigating by using Current-Voltage (I-V) measurement. I-V measurement showed the electrical properties were varied at different annealing temperature. The annealing temperature at 500°C has the highest electrical conductance properties.

Microwave-Enzyme-Assisted Extraction and Dyeing of Lichen Species: Parmotrema praesorediosum

This research work involves the dyeing of silk fabrics with lichen Parmotrema praesorediosum. The dyes were extracted using two techniques involving microwave-assisted extraction (MAE) and microwave-enzyme-assisted extraction (MEAE). This was found to be comparable with conventional boiling technique. The CIE L*a*b* and K/S values of the dyed samples were measured. Colourfastness properties including washing, rubbing and light of each sample was measured. The research results indicated that modification of MEAE led to higher dye absorption shade compared to MAE and boiling method. The optimal microwave power is 700 W. The colourfastness testing shows that all samples produced good colourfastness for natural dye.

Dyeing Properties and Absorption Study of Natural Dyes from Seaweeds, Kappaphycus alvarezii

This research focuses on the extraction of natural dyes from red, green and brown strains of Kappaphycus alvarezii for textile colourant. The green, brown and red strains of Kappaphycus alvarezii seaweeds were extracted using boiling water and microwave-assisted extraction methods. The extracted colourant was measured with UV–Vis spectrophotometer to analyse the absorbance value at the maximum wavelength or peak absorbance (λmax) as well as to determine the compounds present which contribute to the shades obtained. The dyeing was then performed by exhaustion at 85 °C for 60 min. Alum and iron were used as mordant and applied simultaneously in the dyebath. The dyed samples were then measured using spectrophotometer to analyse the shades obtained with regard to L*a*b* values and reflectance curves. The dyed samples were also compared in terms of their ability to withstand washing, perspiration, rubbing/crocking and light. The results showed that natural dye obtained from microwave-assisted extraction method gave darker shades in comparison with the dye obtained from boiling water extraction. Fastness properties of the dyed samples were evaluated according to MS ISO standard. The results ranged from good to excellent rating except for lightfastness which gave poor rating.

Utilization of Eco-Colourant from Green Seaweed on Textile Dyeing

Synthetic dyes are toxic and harmful to the living things. Therefore, the demand for natural dyes is emerging globally due to the fact that they are safer and more environmental friendly, and thus, the application of natural dyes should be considered as a better alternative to synthetic dyes. Using natural dyes contributes to the acceptability of the product by the customers and also responses to the increasing demand of compatibility with the environment. Along the Malaysian coast, stretching along Peninsula, Sabah and Sarawak are the habitats for marine plants and algae. Previously, seaweeds are used for food, processed products and medicinal usage by local ethnics. However, this research focuses on the extraction of natural dye from green seaweed of Caulerpa lentillifera as textile colourant. Caulerpa lentillifera was extracted using boiling water and ammonia fermentation methods. The dyeing was then performed by exhaustion at 85 °C for 60 min. Three types of mordant were used by metachrome or simultaneous addition of mordant and dye in the dyebath. The dyed samples were then measured using spectrophotometer to analyse the shades obtained with regard to L*a*b* values and K/S values (colour strength). The dyed samples were also compared in terms of their ability to withstand washing, perspiration, rubbing/crocking and light. The results showed that the natural dye obtained from boiling water extraction method gave higher K/S values in comparison with the dye obtained from ammonia fermentation method. Fastness properties of the dyed samples were evaluated according to MS ISO standard and ranged from good to excellent rating except for lightfastness which is poor.