Radically new cellulose nanocomposite hydrogels: Temperature and pH responsive characters.
Innovation produced for synthesis of radically new stimuli-responsive hydrogels were described. The innovation is based on inclusion of cellulose nanowhiskers (CNW)-polyacrylamide (PAAm) copolymer in poly N-isopropyl acrylamide (PNIPAm) semi interpenetrating network (IPN) hydrogel. After being prepared as per free radical polymerization of AAm onto CNW, the as prepared copolymer was incorporated in a polymerization system, which comprises NIPAm monomer, bismethylene acrylamide (BMA) crosslinker, K2S2O8 initiator and TEMED accelerator, to yield CNW-PAAm-PNIPAm nanocomposite hydrogels. The latter address pH-responsive hydrogel as well as temperature-responsive. Hydrogels exhibit the highest equilibrium swelling ratio (ESR) in acidic medium (pH 4). Meanwhile they perform good swelling behavior and hydrophilicity at a temperature of 32°C. These hydrogels carry the characteristic features of CNW-PAAm copolymer as conducted from FTIR and TGA. The hydrogels are homogenous and well-proportioned network structure with highly connected irregular pores with a large size ranging from 30 to 100nm as concluded from SEM.
National Research Centre, Textile Research Division, Dokki, Cairo, Egypt.
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Hebeish
National Research Centre, Textile Research Division, Dokki, Cairo, Egypt.
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Farag
National Research Centre, Textile Research Division, Dokki, Cairo, Egypt.
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Sharaf
National Research Centre, Textile Research Division, Dokki, Cairo, Egypt.
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Shaheen
D002482:Cellulose / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D011108:Polymers / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013818:Thermogravimetry
D020100:Hydrogels; D011108:Polymers; D002482:Cellulose
Cellulose nanowhiskers; Polyacrylamid; Responsive hydrogel