Influence of poly(acrylic acid) xerogel structure on swelling kinetics in distilled water

2006 ◽  
Vol 58 (1) ◽  
pp. 243-252 ◽  
Author(s):  
Jelena Jovanovic ◽  
Borivoj Adnadjevic
Keyword(s):  
Acrylic Acid ◽  
Swelling Kinetics ◽  
Distilled Water ◽  
Poly Acrylic Acid

scholarly journals Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution

2007 ◽  
Vol 72 (11) ◽  
pp. 1139-1153 ◽  
Author(s):  
Aleksandar Kostic ◽  
Borivoj Adnadjevic ◽  
Aleksandar Popovic ◽  
Jelena Jovanovic
Keyword(s):  
Acrylic Acid ◽  
Physiological Solution ◽  
Kinetics Model ◽  
Isothermal Kinetics ◽  
Swelling Kinetics ◽  
Distilled Water ◽  
Equilibrium Degree ◽  
Swelling Rate ◽  
Kinetics Of ◽  
Poly Acrylic Acid

The isothermal kinetics curves of the swelling of a poly(acrylic acid) hydrogel in distilled water and physiological solution at temperatures ranging from 20 to 40 ?C were determined. The possibility of applying both the Fick?s kinetics model and kinetics model of the first order chemical reaction to the swelling kinetics of the PAA hydrogel in distilled water and physiological solution were examined. It was found that the possibilities of applying these models were limited. The new model of the kinetics of swelling in distilled water and physiological solution was established. The kinetic parameters (Ea, ln A) for the swelling in distilled water and physiological solution were determined. The decrease of the equilibrium degree of swelling and the saturation swelling rate of the swelling of the PAA hydrogel in physiological solution compared to swelling in distilled water could be explained by the decreased differences in the ionic osmotic pressures between the hydrogel and the swelling medium. The increase of the initial swelling rate in the physiological solution might be caused by an increased density of charges at the network and by an increased affinity of the network towards the water molecules. The increase of the activation energy of the swelling of the PAA hydrogel in the physiological solution is a consequence of its additional "ionic crosslinking".

scholarly journals SOLVENT OPTIMIZATION OF ELECTROSPUN POLY(ACRYLIC ACID) NANOFIBERS

2021 ◽  
Vol 2021 ◽  
pp. 178-184
Author(s):  
M. Geysoğlu ◽  
F.C. Çallıoğlu
Keyword(s):  
Surface Tension ◽  
Acrylic Acid ◽  
Ph Value ◽  
Fibre Diameter ◽  
Optimum Process ◽  
Distilled Water ◽  
Solution Properties ◽  
Atmospheric Conditions ◽  
Fibre Morphology ◽  
Poly Acrylic Acid

In this study, it was investigated experimentally the influence of various solvents (distilled water and ethanol) on the solution properties, spinning performance, and fibre morphology of the electro spun Poly (acrylic acid) nanofibers. Firstly, polymer solutions were prepared at 5 wt % PAA with various solvent ratios of ethanol and distilled water. Then, solution properties such as viscosity, density, pH, conductivity, and surface tension were determined. The production of nanofiber samples was carried out by electrospinning under the optimum process parameters (voltage, distance between electrodes, feed rate, and atmospheric conditions). Finally, the morphological characterization of the nanofiber surface was carried out with SEM. According to the results, it was observed that conductivity, surface tension and the density of the solution increase as the ethanol ratio decreases. On the other hand, pH value increases as the ethanol ratio increases and, so, the acidic value of the solutions decreases. The viscosity increased until the ethanol/distilled water ratio was 50/50 and then decreased as the ethanol percentage decreased to under 50%. In addition, average fibre diameter decreases with ethanol ratio decreases. It is possible to say that solvent type affects solution properties, fibre morphology and spinning performance significantly. Generally, fine, uniform and bead free nanofibers could be electro spun and the PAA solution containing 70 wt % distilled water and 30 wt % ethanol was selected as the optimum in terms of fibre morphology, web quality and spinning performance.

Soft ionic liquid based resistive memory characteristics in a two terminal discrete polydimethylsiloxane cylindrical microchannel

2020 ◽  
Vol 8 (38) ◽  
pp. 13368-13374
Author(s):  
Muhammad Umair Khan ◽  
Gul Hassan ◽  
Jinho Bae
Keyword(s):  
Ionic Liquid ◽  
Acrylic Acid ◽  
Sodium Hydroxide ◽  
Sodium Salt ◽  
Resistive Memory ◽  
Cylindrical Microchannel ◽  
Memory Characteristics ◽  
Poly Acrylic Acid

This paper proposes a novel soft ionic liquid (IL) electrically functional device that displays resistive memory characteristics using poly(acrylic acid) partial sodium salt (PAA-Na+:H2O) solution gel and sodium hydroxide (NaOH) in a thin polydimethylsiloxane (PDMS) cylindrical microchannel.

Synthesis of composite superabsorbent of poly (acrylic acid sodium)/humic acid by using glow discharge electrolysis plasma

2012 ◽  
Vol 29 (4) ◽  
pp. 376
Author(s):  
Jie REN ◽  
Lihong TAO ◽  
Jinzhang GAO ◽  
Yan LI ◽  
Hongwei LIU ◽  
...  
Keyword(s):  
Humic Acid ◽  
Glow Discharge ◽  
Acrylic Acid ◽  
Glow Discharge Electrolysis ◽  
Glow Discharge Electrolysis Plasma ◽  
Poly Acrylic Acid

Reactions of macroions with ester and carboxylic groups of polymers

1987 ◽  
Vol 52 (9) ◽  
pp. 2194-2203
Author(s):  
Miloslav Kučera ◽  
Dušan Kimmer ◽  
Karla Majerová ◽  
Josef Majer
Keyword(s):  
Maleic Anhydride ◽  
Acrylic Acid ◽  
Methyl Methacrylate ◽  
Bond Formation ◽  
Covalent Bond ◽  
The Other ◽  
Poly Methyl Methacrylate ◽  
Other Hand ◽  
Carboxylic Groups ◽  
Poly Acrylic Acid

In the reaction of dianions with poly(methyl methacrylate), only an insignificant amount of insoluble crosslinked product is obtained. If, however, the concentration of grafting dianions approaches that of ester groups, the amount of poly(methyl methacrylate) which may thus be crosslinked becomes quite significant. Dications, too, can bring about crosslinking of only an insignificant number of poly(methyl methacrylate) chains. Carboxylic groups in poly(acrylic acid) react with dianions and dications in an anhydrous medium similarly to ester groups. On the other hand, in the presence of a cocatalytic amount of water dications are more readily bound to carboxylic groups, forming a covalent bond. The relatively highest efficiency was observed in the bond formation between dication and the poly[styrene-alt-(maleic anhydride)], both in an anhydrous medium and in the presence of H2O.

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