Swelling Behaviors of Acrylic-Based Superabsorbent Fibers

2012 ◽  
Vol 476-478 ◽  
pp. 1331-1335
Author(s):  
Qi Xia Liu ◽  
Zhi Rong Ding ◽  
Zhen Dong
Keyword(s):  
External Solution ◽  
Ion Concentration ◽  
Water Absorbency ◽  
Absorption Mechanism ◽  
Ph Values ◽  
Ionic Valence ◽  
Swelling Equilibrium ◽  
Saline Solutions ◽  
Osmotic Pressure Difference ◽  
Swelling Behaviors

The swelling behaviors of SAF in distilled water and various saline solutions were investigated and the absorption mechanism of SAF was discussed. Emphasises were laid on the effects of swelling time, saline solutions as well as the pH values of solutions on water absorbency of SAF. Results showed that water absorbency of SAF was significantly influenced by ion concentration and ionic valence of saline solutions as well as the pH values of solutions, but it was less affected by swelling time after reaching swelling equilibrium. The absorption mechanism of SAF is consistent with Flory’s theory of network and the osmotic pressure difference between SAF and the external solution is the motive force for swelling of SAF.

Swelling Behavior of Poly(Acrylamide) Nanoclay Composite Hydrogels

2008 ◽  
Vol 47-50 ◽  
pp. 230-233
Author(s):  
Peng Li ◽  
Siddaramaiah ◽  
Ok Kyung Park ◽  
Nam Hoon Kim ◽  
Seok Bong Heo ◽  
...  
Keyword(s):  
Saline Solution ◽  
In Situ Polymerization ◽  
Ph Value ◽  
Water Absorbency ◽  
Ph Values ◽  
Swelling Capacity ◽  
Influence Of Ph ◽  
Swelling Behaviors ◽  
Poly Acrylamide

A series of nanocomposite (NC) hydrogels were synthesized by in-situ polymerization of acrylamide (AAm) monomer using laponite XLS clay as a crosslinker. This paper focused on water absorbency of the NC hydrogels with various clay contents, at various pH values and ionic strengths. The influence of pH value on swelling behaviors showed that a maximum swelling ratio was observed at pH 11. The swelling abilities of the NC composites decreased in saline solution strength. Heat treatment of NC hydrogels improved the swelling capacity of the hydrogels.

Prediction and Analysis of Reinforcement Corrosion in Simulated Concrete Pore Solution Based on Neural Network

2020 ◽  
Vol 34 (14) ◽  
pp. 2059047
Author(s):  
Fengjiao Jiang ◽  
Jinxin Gong ◽  
Jichao Zhu ◽  
Huan Wang ◽  
Weibo Song
Keyword(s):  
Neural Network ◽  
Equivalent Circuit ◽  
Pore Solution ◽  
Equivalent Circuit Model ◽  
Chloride Ion ◽  
Ion Concentration ◽  
Equivalent Circuits ◽  
Chromium Alloy ◽  
Ph Values ◽  
Impedance Characteristics

The corrosion of reinforcement has always been a problem to be solved in the field of architecture. In this paper, the corrosion characteristics of chromium alloy steel under different pH conditions are studied. The impedance characteristics and equivalent circuit are predicted by neural network model. First of all, in simulated pore solution with different pH values, the characteristics of Nyquist impedance spectroscopy of the whole chromium alloy under passivation stage and the damaged passivation film of reinforcing bars under initial corrosion stage have been found. Then, according to the difference of impedance characteristics under different pH values, different equivalent circuits have been established and [Formula: see text] values of different equivalent circuits under different chloride ion concentration have been calculated. By fitting the electrochemical parameters of the equivalent circuit with [Formula: see text] values, the equivalent circuit model which can be predicted by neural network has good consistency with the equivalent circuit which can be predicted by [Formula: see text] values.

scholarly journals Block of single L-type Ca2+ channels in skeletal muscle fibers by aminoglycoside antibiotics.

1996 ◽  
Vol 107 (3) ◽  
pp. 421-432 ◽  
Author(s):  
C M Haws ◽  
B D Winegar ◽  
J B Lansman
Keyword(s):  
Skeletal Muscle ◽  
Single Channel ◽  
Muscle Fibers ◽  
External Solution ◽  
Bimolecular Reaction ◽  
Aminoglycoside Antibiotics ◽  
Ion Concentration ◽  
Ion Flow ◽  
Skeletal Muscle Fibers ◽  
Ca2 Channels

The activity of single L-type Ca2+ channels was recorded from cell-attached patches on acutely isolated skeletal muscle fibers from the mouse. The experiments were concerned with the mechanism by which aminoglycoside antibiotics inhibit ion flow through the channel. Aminoglycosides produced discrete fluctuations in the single-channel current when added to the external solution. The blocking kinetics could be described as a simple bimolecular reaction between an aminoglycoside molecule and the open channel. The blocking rate was found to be increased when either the membrane potential was made more negative or the concentration of external permeant ion was reduced. Both of these effects are consistent with a blocking site that is located within the channel pore. Other features of block, however, were incompatible with a simple pore blocking mechanism. Hyperpolarization enhanced the rate of unblocking, even though an aminoglycoside molecule must dissociate from its binding site in the channel toward the external solution against the membrane field. Raising the external permeant ion concentration also enhanced the rate of unblocking. This latter finding suggests that aminglycoside affinity is modified by repulsive interactions that arise when the pore is simultaneously occupied by a permeant ion and an aminoglycoside molecule.

Heat Resistance of Alicyclobacillus acidoterrestris Spores as Affected by Various pH Values and Organic Acids‡

1998 ◽  
Vol 61 (1) ◽  
pp. 41-46 ◽  
Author(s):  
APRIL J. PONTIUS ◽  
JOHN E. RUSHING ◽  
PEGGY M. FOEGEDING
Keyword(s):  
Heat Resistance ◽  
Fruit Juice ◽  
Ion Concentration ◽  
Thermal Processes ◽  
Alicyclobacillus Acidoterrestris ◽  
Hydrogen Ion Concentration ◽  
Ph Values ◽  
Acid Type ◽  
Acidic Conditions ◽  
D Values

Alicyclobacillus acidoterrestris, a thermoacidophilic sporeformer, has caused spoilage of fruit juices which had been treated with thermal processes intended to commercially sterilize the juice. The objective of this research was to document the effect of pH, acid, and temperature on the heat resistance of spores of three fruit-juice isolates of A. acidoterrestris. The thermal resistance of spores of A. acidoterrestris strains VF, WAC, and IP were studied in a model fruit-juice system composed of 12% glucose and 30 mM of either citric, malic, or tartaric acid, adjusted to selected pH values ranging from 2.8 to 4.0. Decimal reduction times (D values) and inactivation rates were determined. Spores of strains VF and WAC were similarly resistant to heat under acidic conditions, while strain IP spores were less resistant. In the range of pH 2.8 to 4.0, a statistically significant effect of hydrogen ion concentration on heat resistance was observed at lower temperatures, but not at the higher temperatures. For example, at 91 °C and pH 3.1 and 3.7, D values were 31.3 and 54.3 min, respectively, while at 97°C D values at pH 3.1 and 3.7 were 7.9 and 8.8 min, respectively. The type of acid did not significantly affect the heat resistance. The zD values ranged from 5.9 to 10°C, depending on the acid, pH, and the strain. The models generated from this research can be used to determine adequate thermal processes, accounting for the acid type, pH, and temperature, to destroy A. acidoterrestris spores in beverages, since this organism is able to survive the typical hot-fill and hold process (2 min at 88 to 96°C) currently used to process fruit juice.

THE ELECTRODE POTENTIAL OF IRON IN RELATION TO HYDROGEN ION CONCENTRATION

1936 ◽  
Vol 14b (1) ◽  
pp. 31-40 ◽  
Author(s):  
J. W. Shipley ◽  
J. H. Shipley
Keyword(s):  
Electrode Potential ◽  
Chloride Ion ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Iron Electrode ◽  
General Corrosion ◽  
Citrate Buffer ◽  
Hydrogen Ion Concentration ◽  
Electrically Conducting ◽  
Ph Values

The electrode potential of iron immersed in phosphate, borate and citrate buffers of varying hydrogen ion concentration was measured, using a normal calomel electrode as the second half of the cell. Breaks in the potential of the iron electrode amounting to as much as 0.7 volts were found to occur at definite pH values for each series of buffers. The electrode exhibited an "initial" and "final" potential depending on the pH of the electrolyte and the time of immersion, the "final" value requiring several days to become established. The "final" break in the electrode potential of 0.74 volts in the pure phosphate buffer occurred between a pH of 3.1 and 4.0, that in the pure borate buffer, of 0.75 volts, occurred between a pH of 4.3 and 4.6, and in the pure citrate buffer, of 0.77 volts, between a pH of 10.1 and 10.9. The effect of chloride ion and de-aeration on the electrode potential was observed. It is suggested that the potential of the iron electrode is determined by the presence or absence of a non electrically conducting film or deposit on the iron, the formation of which is a function of the nature of the electrolyte and its hydrogen ion concentration. De-aeration apparently had no effect on the electrode potential, but the presence of chloride ion affected the establishing of the "final" potential and caused the break in voltage to appear irregularly at a much lower hydrogen ion concentration.At pH values below that at which the break in potential occurred, corrosion of the iron electrode was marked, and the electrode potential remained high, while, at pH values above the break, corrosion was virtually inhibited or confined to local spots on the electrode, and the electrode potential remained low. The presence of the chloride ion stimulated local corrosion and permitted general corrosion to proceed at a lower hydrogen ion concentration.

The Influence of Different Ph Values and High Concentrations of Na2SO4 and NaCl on the Photocatalytic Oxidation (PCO) of Methylene Blue (MB) by Aqueous Suspension of Nano-Sized TiO2

2012 ◽  
Vol 490-495 ◽  
pp. 3892-3896
Author(s):  
Yu Ping Jiang
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Oxidation ◽  
High Salinity ◽  
Aqueous Suspension ◽  
Ion Concentration ◽  
Ph Values ◽  
Orthogonal Experiments ◽  
Degradation Rates ◽  
The Difference ◽  
High Concentrations

To study the PCO of high-salinity organic wastewater, nano-sized TiO2 was used for PCO of MB in solutions with different pH values and high concentrations of Na2SO4 or NaCl. The rates of PCO were monitored by total organic carbon (TOC) measurement. The results showed that the degradation rates increased with increasing pH and decreased as the concentration of Na2SO4 or NaCl increased. The difference of degradation rates in Na2SO4 or NaCl aqueous solutions increased as the ion concentration increased. In the orthogonal experiments, the rates decreased remarkably under certain ratios of the ions concentration. The mechanisms were explored in some detail.

COMPARATIVE RESPONSE OF TWO SAPROPHYTIC AND TWO PLANT PARASITIC SOIL FUNGI TO TEMPERATURE, HYDROGEN-ION CONCENTRATION, AND NUTRITIONAL FACTORS

1961 ◽  
Vol 39 (1) ◽  
pp. 65-79 ◽  
Author(s):  
E. W. B. Ward ◽  
A. W. Henry
Keyword(s):  
Soil Fungi ◽  
Inorganic Nitrogen ◽  
Synthetic Medium ◽  
Trichoderma Viride ◽  
Nitrogen Sources ◽  
Ion Concentration ◽  
Good Growth ◽  
Hydrogen Ion Concentration ◽  
Nutritional Factors ◽  
Ph Values

The behavior of two soil saprophytes, Trichoderma viride and Trichocladium asperum, and two root-infecting fungi, Ophiobolus graminis and Fomes annosus, was compared under various conditions in laboratory culture.On an agar-solidified organic medium optimum temperatures for growth were approximately: T. viride 25–30 °C, T. asperum 20–25 °C, O. graminis 20–25 °C, F. annosus 25 °C. T. viride rapidly outgrew the other fungi in the optimum range but this relationship changed at lower temperatures, its growth rate being equalled by that of O. graminis at 10 °C. T. viride was the only fungus to grow at 35 °C. In a synthetic liquid medium adjusted to pH values from 3.0–7.0 with a citrate–phosphate buffer, growth of O. graminis and F. annosus was sharply reduced at pH values below 5.0. T. viride made good growth at pH 3.1 and reduction in growth of T. asperum occurred only below pH 4.0. Both parasites required thiamine for growth in a synthetic medium and O. graminis also required biotin; in addition they showed a preference for organic as opposed to inorganic nitrogen sources. T. viride and T. asperum grew well with KNO3 as nitrogen source and neither required vitamins. D-Glucose, D-fructose, and D-mannose were readily utilized, and D-arabinose poorly utilized, by all four fungi. Utilization of other hexoses, pentoses, disaccharides, and polysaccharides varied considerably between the fungi.The relationship of the results obtained to the observations of others on the ecology of soil fungi is discussed and the possibility that combinations of physical and nutritional factors may favor specific fungi in the soil is considered.

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