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Title: Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

Abstract

The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towardsmore » pH and temperature can be developed further as drug carrier.« less

Authors:
; ;  [1];  [2]
  1. Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia)
  2. Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)
Publication Date:
OSTI Identifier:
22308330
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1614; Journal Issue: 1; Conference: 2014 UKM FST postgraduate colloquium, Selangor (Malaysia), 9-11 Apr 2014; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
38 RADIATION CHEMISTRY, RADIOCHEMISTRY AND NUCLEAR CHEMISTRY; ACID HYDROLYSIS; ACRYLIC ACID; BLEACHING; CELLULOSE; CROSS-LINKING; MIXTURES; NANOSTRUCTURES; PH VALUE; SCANNING ELECTRON MICROSCOPY; SENSITIVITY; SWELLING

Citation Formats

Lim, Lim Sze, Ahmad, Ishak, Lazim, Mohd Azwani Shah Mat, and Amin, Mohd. Cairul Iqbal Mohd. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC). United States: N. p., 2014. Web. doi:10.1063/1.4895224.
Lim, Lim Sze, Ahmad, Ishak, Lazim, Mohd Azwani Shah Mat, & Amin, Mohd. Cairul Iqbal Mohd. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC). United States. doi:10.1063/1.4895224.
Lim, Lim Sze, Ahmad, Ishak, Lazim, Mohd Azwani Shah Mat, and Amin, Mohd. Cairul Iqbal Mohd. Wed . "Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)". United States. doi:10.1063/1.4895224.
@article{osti_22308330,
title = {Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)},
author = {Lim, Lim Sze and Ahmad, Ishak and Lazim, Mohd Azwani Shah Mat and Amin, Mohd. Cairul Iqbal Mohd},
abstractNote = {The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.},
doi = {10.1063/1.4895224},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1614,
place = {United States},
year = {Wed Sep 03 00:00:00 EDT 2014},
month = {Wed Sep 03 00:00:00 EDT 2014}
}
  • From joint meeting of the American Nuclear Society and the Atomic Industrial Forum and Nuclear Energy Exhibition; San Francisco, California, USA (11 Nov 1973). See CONF-731101-.
  • Previous work has shown that gelation of poly(acrylic acid) in solution occurs most readily in acid form in the presence of 0.01N NaCl. The present investigation was carried out to elucidate in more detail the mechanism of crosslinking occurring in these concentration ranges. Irradiation of the deaerated solutions below the critical concentration led to main-chain scission when NaCl concentrations of solutions to be irradiated were lower than 0.01N. However, in the case of the solutions containing NaCl above 0.01N, the solutions became turbid on irradiation. Detailed studies on properties of these turbid solutions revealed that the origin of turbidity canmore » be attributed to the formation of intra-molecular crosslinking. The reduced viscosities of the intra- molecular-crosslinked polymer were considerably lower than those of the linear polymer over the polymer concentration range studied, and the increase in the reduced viscosity usually observed at lower concentrations was very slight in the case of intramolecular-crosslinked polymer. The values of pH of the intra- molecular-crosslinked polymer were higher than those of the linear polymer. The present study confirms the conclusion in the previous paper that the crosslinking of polyelectrolyte in aqueous solutions can be explained only in terms of both the change in expansion and the repulsion due to ionized groups. (auth)« less
  • Dilute aqueous solutions of poly(acrylic acid) in acid form and in sodium-salt form were irradiated with gamma rays from a Co/sup 60/ source both in the presence and in the absence of air. Changes in gelation dose and viscosity were measured. On irradiation in the absence of air, gel formation was observed, and both the gelation dose and the critical concentration for gel-formation increased as the degree of neutralization of polymers increased. The critical concentrations were 0.25, 0.30, 0.56, and 1.0 wt%, for polymers with degrees of neutralization of 0, 5, 10, and 20%, respectively. When NaCl was added tomore » the solution for irradiation so as to diminish the ionization of carboxyl groups, gelation occurred more readily with increasing NaCl concentration, if the NaCl concentration was relatively low. However, as the concentration of NaCl became higher than 0.01N, gel formation was increasingly suppressed with increasing NaCl concentration. This fact demonstrates that there is an optimum expansion of polyion for crosslinking in aqueous solution. On irradiation in the presence of air, the polymer appeared to degrade exclusively. The higher the degree of neutralization, the higher the degree of degradation. If, however, NaCl was present sufficiently in the solution for irradiation, degradation did not occur practically. (auth)« less
  • Mesoporous silicas with hexagonally arranged pore channels were synthesized in water–ethanol-ammonia solution using cetyltrimethylammonium bromide as template. Directed modification of silica surface with N-[N′-(N′-phenyl)-2-aminophenyl]-3-aminopropyl groups was realized by postsynthetic activation of halogenoalkylsilicas, which have surface uniformly or selectively distributed 3-chloropropyl groups, with 2-aminodiphenylamine in the liquid phase. Chemical composition of silica materials was estimated by IR spectroscopy and chemical analysis of the surface products of reactions. Characteristics of porous structure of MCM-41-type silicas were determined from X-ray and low-temperature nitrogen ad-desorption measurements. Release ability of synthesized silica carriers was established on encapsulation of 4-aminobenzoic acid in pore channels and subsequentmore » delivery at pH=6.86 and pH=1.00. It was found that N-[N′-(N′-phenyl)-2-aminophenyl]-3-aminopropyl groups block pore entrances at neutral pH preventing 4-aminobenzoic acid release. At pH=1.00 repulsion of positively charged surface aromatic amino groups localized near pore orifices provides unhindered liberation of aromatic amino acid from mesoporous channels. - Graphical abstract: Blocking of pores with N-[N′-(N′-phenyl)-2-aminophenyl]-3-aminopropyl groups at pH=6.86 for storage of ABA and opening of pore entrances at pH=1.00 for unhindered ABA liberation. - Highlights: • Modification of MCM-41 with N-[N′-(N′-phenyl)-2-aminophenyl]-3-aminopropyl groups. • Study of release ability of synthesized silica carriers in relation to amino acid. • Controlled blocking and opening of pores by amino groups at pH change were performed. • Retention of amino acid at pH=6.86 and its liberation at pH=1.00 was proved.« less