Papers by Keyword: Polyacrylamide Hydrogel

Abstract: Atomic Force Microscopy (AFM) technology has ushered researchers to directly observe surface topology and the substrate mechanical properties using specialized probe. AFM is one of the microscopic techniques with the highest lateral resolution which can be employed in air or even in liquids. In this experiment, we characterized the local elastic properties of the polyacrylamide (PA) hydrogel using Atomic Force Microscopy (AFM). PA consists of huge units of an organic acrylamide monomers which can be saturated to form a highly water-swollen hydrogel. The hydrogel offers tunable density with a high degree of pliability which depends of its applications. Such applications of PA hydrogel can be in cell substrate studies and measurement of cell-generated forces. Our results with AFM measurement yielded force-distance curves were used to determine the elastic behaviour of the polyacrylamide (PA) hydrogel. Analysis has shown that 15% w/v PA hydrogel concentration has Young’s modulus, Y_av=1608.9 ± 1.3 kPa (n=8) and transverse stiffness, K_av=88.7 ± 9.7 μN/nm (n=8) at Thus, elasticity measurements has provided useful insights for the future experiment on traction force microscopy with amoeboid organism.

Abstract: Pineapple leaf fibers (PALF) have several advantages such as low cost, eco-friendly, and high specific strength. However, the brittleness of PALF limits its application. To overcome this limitation of PALF, it is essential to synergize the advantages of PALF with elastic properties of hydrogel. In this study, PALF was coated with polyacrylamide (PAAm) hydrogel under direct UV light exposure (UVA>300nm). Prior to this coating, PALF was alkali treated to introduce more OH group on PALF fiber. The main purpose of this study was to investigate the effect of untreated/treated PALF coated PAAm hydrogel on the flexibility of the fiber using tensile measurements. From the results, treated PALF coated PAAm hydrogel showed better results in tensile properties compared to untreated PALF due to the alkali treatment which improved the interfacial adhesion between PAAm hydrogel and fiber surface. In general, this study is precursor for further development in natural fiber coating technology.

Abstract: Double network (DN) hydrogels have drawn considerable attention as innovative materials possessing both high water content as well as improved mechanical properties. In this study, DN hydrogels were formed from a combination of two hydrogel networks. The first network composed of acrylamide (AAm) and N’,N’-methylenebisacrylamide (MBAAm). AAm and MBAAm were covalently crosslinked via photopolymerization simultaneously with/without the presence of the second network pre-gel mixture; physically crosslinked gelatin-calcium carbonate (GCa). The mechanical properties characterization of the hydrogels revealed that tensile strength, Young’s modulus and elongation at break increased with the increasing amount of second network component; i.e. GCa. These data could confirmed that the polyacrylamide (PAAm)-GCa DN hydrogels possessed ‘stretchability’ character. Overall, PAAm-GCa DN hydrogels had shown better mechanical strength than the PAAm single network hydrogels. We foreseen that DN hydrogels are highly potential to be developed as artificial muscles.

Abstract: The release mechanisms and the diffusion coefficients of salicylic acid -loaded polyacrylamide hydrogels are investigated experimentally by using a modified Franz-Diffusion cell at the temperature of 37 °C to determine the effects of crosslinking ratio and electric field strength. The fabricated hydrogels retain their physical shapes and sizes during the experiments along with data reproducibility. A significant amount of salicylic is released within 48 h from the hydrogels of various crosslinking ratios, with and without electric field. The release profile of Q vs. t1/2 is linear. Diffusion coefficient, determined from the Higuchi equation, increases with electric field strength and reach maximum values at electric field strength of 0.1 V due to the electrophoresis of the drug, and it becomes saturated at electric field strengths between 0.5 – 10 V.