Tag Archives: Papia Haque

Preparation and characterization of poly (ethylene glycol) grafted Caalginate fibers by γ-irradiation for biomedical applications

Author
Md. Kamal Khan,
Applied Chemistry and Chemical Engineering
University of Dhaka
Mohammed Mizanur Rahman,
Applied Chemistry and Chemical Engineering
University of Dhaka
Bodrun Nesa,
Applied Chemistry and Chemical Engineering
University of Dhaka
Abstract:
Radiation processing, being a physical process, is an environmentally friendly alternative to chemical modifications. It is economically viable, safe, and possesses several advantages over other conventional methods employed for modification and grafting. To improve the physico-mechanical properties of Ca-alginate fiber (CaAF), poly (ethylene glycol) (PEG) was grafted by applying γ-radiation of different intensities. The effect of γ-irradiation on the physico-mechanical, thermal, morphological, thermal and water aging, water, and simulated body fluid (SBF) uptake were evaluated. FT-IR results confirmed that PEG was successfully grafted onto Ca-alginate fibers by γ-irradiation. From the detailed experimental results, irradiation doses and PEG concentration were optimized for grafting processes. The results showed that 50% PEG and 2.5 kGy irradiation dose yielded the highest tensile strength. Differential scanning calorimetric (DSC) analysis showed that with increasing γ-intensity a decrease of dehydration temperature of the fibers had occurred. On the other hand, the glass transition temperature (Tg) increased with increasing irradiation dose. The tensile cracked surfaces of the grafted alginate fibers were analyzed by scanning electron microscope (SEM) in order to monitor their surface morphologies. The SEM images of the cracked surfaces demonstrated that spherical shape rods were present for irradiated fiber sample while no such rods were observed for non-irradiated fibers. The characteristic data obtained from SBF and water uptake, and water and thermal aging experiments indicated that CaAF grafted with 50% PEG by applying 2.5 kGy γ-irradiation can be potentially
employed for biomedical purposes, such as surgical suture.
For details please see the attached file:

Radiation Physics and Chemistry

Author
Mohammed Mizanur Rahman
Applied Chemistry and Chemical Engineering
University of Dhaka
Shahriar Kabir
Applied Chemistry and Chemical Engineering
University of Dhaka
Taslim Ur Rashid
Applied Chemistry and Chemical Engineering
University of Dhaka

Abstract:

In the present study we have synthesized chitosan from waste prawns hell via g-irradiation of chitin and subsequent alkaline treatment. The detailed experimental studies demonstrated that nonirradiated chitin deacetylated by 40% NaOH solution showed 72% degree of deacetylation(DD), however 50k Gy irradiated chitin, deacetylated by 20% NaOH demonstrated 81.5% DD. Chitosanin solid state as obtained from g-irradiation of chitin was further irradiated by different doses(2–100kGy) of gamma irradiation and the effects of irradiation on the molecular weight, the rmo-mechanical by differential scanning calorimetry(DSC) and thermogravimetric analysis (TGA), and antimicrobial properties were evaluated with respect to nonirradiated chitosan sample. Gamma irradiation of chitosan with a dose of 100kGy caused a decrease in average molecular weight from1.9_105 to 6.5_104 Da  and thus increased its solubility in water. Nonirradiated and g-irradiated chitosan at concentration 1% (w/w) in water were prepared and used to evaluate of its potentiality for growth stimulation of Malabar spinach. The chitosan solution was sprayed on the specimen plants and neighboring soil where germinations were taken place and various plant growth parameters such as plan th eight, number of leaves, leaf areas, dry and wet weight of the plants and roots were investigated. The details study revealed that application of 30 k Gyirradiated chitosan yielded 60% higher growth of the Malabar spinach than that obtained from Nonirradiated chitosan. The data are consistent with preliminary results from field experiments and unambiguously confirms that a minor amount of chitosan has a pro found effect on the growth and development of Malabar spinach. 

For details please see the attached file: