scholarly journals Water Absorption Enhancement of Sodium Poly Acrylate and Poly(2-Acrylamido-2-Methylpropane Sulphonic Acid) Based Hydrogel Mixtures

2021 ◽  
Vol 15 (1) ◽  
pp. 49-54
Author(s):  
Sohair A. Darwish ◽  
Ibrahim M. Ibrahim ◽  
Nasser Y. Mostafa ◽  
Mostafa A. Radwan ◽  
Mohamed A. Sadek ◽  
...  
Keyword(s):  
Free Radical ◽  
Sulfonic Acid ◽  
Room Temperature ◽  
Three Dimensional ◽  
Sulphonic Acid ◽  
Hydrophilic Polymers ◽  
Absorption Enhancement ◽  
Solution Polymerization ◽  
Swelling Capacity ◽  
Glass Tubes

Introduction: Hydrogels are hydrophilic polymers which are cross-linked to form three-dimensional structures, which can absorb, swell and retain huge amounts of water or aqueous fluids. Objective: This paper reports the preparation and characterisation of Poly(2-Acrylamido-2-Methylpropane Sulphonic Acid) (PAMPS) hydrogel with different crosslinking intensities. Methodology: 2-Acrylamido-2-methylpropane sulfonic acid (AMPS) monomer was purchased from Alfa Aesar Company as reagent grade. It was used as received (>98% purity) without any further purification. PAMPS hydrogel was prepared by free radical crosslinking solution polymerization of AMPS in water at room temperature under a nitrogen blanket in cylindrical glass tubes. The characteristics of the obtained PAMPS hydrogel were compared with those of commercial sodium polyacrylates hydrogel. Results: It was found that decreasing the crosslinker weight improved the absorbance capacity but to a limit. The suggested reasons were discussed. The mixture showed higher absorbance rate than PAMPS, and bigger absorbance capacity than sodium polyacrylates. Conclusion: This paper investigates the effect of crosslinker ratio on the swelling capacity of PAMPS. It was found that as the crosslinking ratio decreases, the porosity of the hydrogel increases, thus improving the swelling capacity.

The ephemeral dihydrate of sulfanilic acid

2018 ◽  
Vol 74 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Stefanie Langenstück ◽  
Chenchen Zhao ◽  
Ulli Englert
Keyword(s):  
Sulfonic Acid ◽  
Room Temperature ◽  
Three Dimensional ◽  
Sulfanilic Acid ◽  
Interplanar Distance ◽  
Water Molecules ◽  
Sulfonate Group ◽  
Aromatic Rings ◽  
Dimensional Network ◽  
Pure Phase

Evaporation of an aqueous solution of sulfanilic acid (systematic name: 4-aminobenzene-1-sulfonic acid) at 273 K affords a crystalline dihydrate, C6H7NO3S·2H2O. The organic molecule exists as a zwitterion; two zwitterions are aligned in an antiparallel fashion about a crystallographic centre of inversion. They interact directly via two N—H...O hydrogen bonds between the ammonium group of one zwitterion and the sulfonate group of its symmetry-related counterpart, and their aromatic rings are π-stacked, with an interplanar distance of 3.533 (3) Å. One of the cocrystallized water molecules connects the resulting pairs into layers and the second crosslinks the layers into a three-dimensional network. All H atoms connected to N or O atoms find acceptors in suitable geometries. In the resulting crystal, polar and hydrogen-bond-dominated slabs alternate with stacks of organic arene rings. Although the new dihydrate shows efficient space filling, with a packing coefficient of 75.7%, it is unstable and undergoes fast desolvation at room temperature. In this process, the orthorhombic ansolvate forms as a pure phase.

Plasma Thromboplastin Component (Christmas Factor, Factor IX) Levels in Stored Human Blood and Plasma

1960 ◽  
Vol 04 (03) ◽  
pp. 376-388 ◽  
Author(s):  
J Dieter Geratz ◽  
John B. Graham
Keyword(s):  
Human Plasma ◽  
Human Blood ◽  
Whole Blood ◽  
Room Temperature ◽  
Close Agreement ◽  
Factor Ix ◽  
Deficient Patient ◽  
Glass Tubes ◽  
Disodium Hydrogen Citrate ◽  
Bank Blood

Summary1. PTC activity was assayed in 26 units of human plasma prepared from whole blood stored for 3 weeks at 4° C. The plasma had been frozen and stored at — 20° C for additional periods ranging from a few days to 4 months. High PTC activity was still present in the plasma at the end of this period, the activity averaging 95% of normal.2. The PTC activity of 19 samples of “reclaimed“ plasma stored for an additional 6 months at — 20° C decreased by an average of 23%. This decrease was statistically significant.3. Liquid plasma kept at room temperature for 5½—7½ months contained no PTC activity.4. Lyophilized plasma stored at room temperature for 6—8 years contained an average of 30% PTC activity. Lyophilized plasma stored at — 20° C for 4 years contained 68% PTC activity.5. ACD and disodium hydrogen citrate anticoagulant solutions served equally well in preserving PTC activity in whole blood stored in glass tubes over a period of 3 weeks at 4° C.6. “Reclaimed“ plasma from outdated bank blood provided effective hemostasis in two operations for the removal of 20 teeth from a severely PTC-deficient patient.7. The high PTC activity of “reclaimed“ plasma was confirmed by the close agreement between the PTC level expected in a PTC deficient patient after transfusion of such plasma and that observed.

An Efficient Synthesis of 2-Substituted Quinazolin-4(3H)-ones by Using Recyclable Wang Resin Supported Sulfonic Acid Catalyst

2020 ◽  
Vol 17 ◽  
Author(s):  
Kalyani K. ◽  
Srinivasa Reddy Kallam
Keyword(s):  
Sulfonic Acid ◽  
Functional Group ◽  
Acid Catalyst ◽  
Sulphonic Acid ◽  
Isatoic Anhydride ◽  
Efficient Synthesis ◽  
Wang Resin ◽  
Polymer Supported ◽  
High Yields

Abstract:: An efficient synthesis of 2-substituted Quinazolin-4(3H)-ones has been developed from isatoic anhydride with various amidoximes by using recyclable polymer supported sulphonic acid catalyst. Excellent functional group compatibil-ity and high yields are the important features of this protocol.

scholarly journals Crystal structure of K[Hg(SCN)3] – a redetermination

2014 ◽  
Vol 70 (9) ◽  
pp. i46-i46 ◽  
Author(s):  
Matthias Weil ◽  
Thomas Häusler
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Three Dimensional ◽  
Lattice Parameters ◽  
Bond Lengths ◽  
Dimensional Network ◽  
Anisotropic Displacement Parameters ◽  
Precision And Accuracy ◽  
Standard Deviations ◽  
Atomic Coordinates

The crystal structure of the room-temperature modification of K[Hg(SCN)3], potassium trithiocyanatomercurate(II), was redetermined based on modern CCD data. In comparison with the previous report [Zhdanov & Sanadze (1952).Zh. Fiz. Khim.26, 469–478], reliability factors, standard deviations of lattice parameters and atomic coordinates, as well as anisotropic displacement parameters, were revealed for all atoms. The higher precision and accuracy of the model is, for example, reflected by the Hg—S bond lengths of 2.3954 (11), 2.4481 (8) and 2.7653 (6) Å in comparison with values of 2.24, 2.43 and 2.77 Å. All atoms in the crystal structure are located on mirror planes. The Hg2+cation is surrounded by four S atoms in a seesaw shape [S—Hg—S angles range from 94.65 (2) to 154.06 (3)°]. The HgS4polyhedra share a common S atom, building up chains extending parallel to [010]. All S atoms of the resulting1∞[HgS2/1S2/2] chains are also part of SCN−anions that link these chains with the K+cations into a three-dimensional network. The K—N bond lengths of the distorted KN7polyhedra lie between 2.926 (2) and 3.051 (3) Å.

scholarly journals Ab initiostructure determination of nanocrystals of organic pharmaceutical compounds by electron diffraction at room temperature using a Timepix quantum area direct electron detector

2016 ◽  
Vol 72 (2) ◽  
pp. 236-242 ◽  
Author(s):  
E. van Genderen ◽  
M. T. B. Clabbers ◽  
P. P. Das ◽  
A. Stewart ◽  
I. Nederlof ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Room Temperature ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Direct Methods ◽  
Liquid Nitrogen Temperature ◽  
High Dynamic Range ◽  
Electron Diffraction Data ◽  
High Signal

Until recently, structure determination by transmission electron microscopy of beam-sensitive three-dimensional nanocrystals required electron diffraction tomography data collection at liquid-nitrogen temperature, in order to reduce radiation damage. Here it is shown that the novel Timepix detector combines a high dynamic range with a very high signal-to-noise ratio and single-electron sensitivity, enablingab initiophasing of beam-sensitive organic compounds. Low-dose electron diffraction data (∼0.013 e− Å−2 s−1) were collected at room temperature with the rotation method. It was ascertained that the data were of sufficient quality for structure solution using direct methods using software developed for X-ray crystallography (XDS,SHELX) and for electron crystallography (ADT3D/PETS,SIR2014).

Catalytic etherification of glycerol to tert-butyl glycerol ethers using tert-butanol over sulfonic acid functionalized mesoporous polymer

RSC Advances ◽  
2016 ◽  
Vol 6 (86) ◽  
pp. 82654-82660 ◽  
Author(s):  
Pandian Manjunathan ◽  
Manish Kumar ◽  
Sathyapal R. Churipard ◽  
S. Sivasankaran ◽  
Ganapati V. Shanbhag ◽  
...  
Keyword(s):  
Free Radical ◽  
Radical Polymerization ◽  
Sulfonic Acid ◽  
Solvothermal Method ◽  
Free Radical Polymerization ◽  
Tert Butyl ◽  
Mesoporous Polymer ◽  
Glycerol Ethers ◽  
Tert Butanol

Mesoporous polymers (MP) were synthesized by free radical polymerization of divinylbenzene by a solvothermal method followed by sulfonic acid functionalization by a post synthetic modification with conc.

Thermo-Optical Properties of Perfluorinated Sulfonic Acid Membranes: An Investigation of Hydration Based on Absorption Spectra

2017 ◽  
Vol 71 (11) ◽  
pp. 2504-2511 ◽  
Author(s):  
Daniele T. Dias ◽  
Guy Lopes ◽  
Tales Ferreira ◽  
Ivanir L. Oliveira ◽  
Caroline D. Rosa
Keyword(s):  
Sulfonic Acid ◽  
Room Temperature ◽  
Water Retention ◽  
Structural Changes ◽  
Optical Characterization ◽  
Scanning Calorimetry ◽  
Experimental Procedure ◽  
Nafion Membranes ◽  
Perfluorinated Sulfonic Acid

The Nafion membranes are widely used in electrochemical applications such as fuel cells, chlor-alkali cells, and actuators–sensors. In this work, the thermal-optical characterization of Nafion in acid form was performed by photoacoustic spectroscopy, thermogravimetry, and differential scanning calorimetry. In the experimental procedure three distinct hydration levels were considered: (1) pristine membrane (λ ≅ H2O/–SO3H ≅ 5.6); (2) swelling process (λ ≅ 17.4); and (3) drying at controlled room temperature after swelling process (λ ≅ 6.5). The discovered behaviors showed significant irreversible structural changes induced by water retention in the membrane. These structural changes depend on the water population present in the clusters and also affect the directional thermal diffusivity of the membrane irreversibly.

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