%0 Journal Article
%T In Situ Disassembling Behavior of Composite Hydrogels for the Efficient Removal of Crystal Violet Dye from Aqueous Solution
%A Venkatesan Srinivasan
%A Sundaram Thiraviam
%A Kullagounder Subramani
%A Sibi Srinivasan
%A Pragathiswaran Chelliah
%A Stanley Anthuvan Babu
%J ISRN Polymer Science
%D 2014
%R 10.1155/2014/632348
%X A novel method for the disassembly of synthetic hydrogels in situ and thereby enhanced adsorption of crystal violet dye is reported. Silicon present in the husk ashes of Panicum miliare is used as the trigger for disassembly of poly(2-acrylamido-1-propane sulfonic acid-co-itaconic acid) hydrogels. Disassembling ability of the ash was determined by changing the temperature of the husk ash. Surface area and particle sizes of both the disassembled and assembled forms of the hydrogels were determined by E. Suito¡¯s method. Removal of crystal violet dye from aqueous solution and the respective adsorption capacities of disassembled and assembled forms of hydrogels were compared by varying parameters such as pH, temperature, and agitation speed. Concentration of the dye in aqueous solution was determined by using UV-Visible spectrophotometer. FTIR analysis was carried out for the characterization of the hydrogels, ash blended hydrogels, and the free ashes. SEM imaging was carried out to differentiate the surfaces of the assembled and disassembled hydrogels. 1. Introduction Many researches are being done on hydrogels to increase and improve their applications in various fields. Cross-linked hydrophilic polymers made hydrogels have capacity for expanding their volumes by their high capacity for water absorption [1, 2] that makes them suitable for purification of wastewater, drug delivery [3], and so forth. The use of hydrogels is known since the late 1950s in the form of the bioengineered contact-lenses [4]. Recently hydrogels such as poloxamers are useful in regenerative medicine. The adsorption ability of aromatic organic molecules of the polymer hydrogels [5] has provided a very good option for polymer adsorbents. Like few other hydrogels poly(2-acrylamido-1-propane sulfonic acid-co-itaconic acid) [poly(AMPS-co-IA)] hydrogels are reported to be good adsorbents for the removal of methylene blue dye [6] and few metal ions [7, 8] from aqueous solution. Crystal violet has been largely used in numerous commercial textile processes as a dye and also in human and veterinary medicines as a biological stain [9, 10]. When discharged into the aquatic system, it can cause severe environmental degradation. The dye has a blue-violet colour with an extinction coefficient of 87,000£¿M£¿1£¿cm£¿1 and an absorbance maximum at 590£¿nm when dissolved in water [11]. Crystal violet has been classified as a recalcitrant. That makes it difficult for the metabolism of living microbes and hence the dye has extended lifetime in various environments [12]. Crystal violet is highly toxic,
%U http://www.hindawi.com/journals/isrn.polymer.science/2014/632348/