scholarly journals Dynamics and Rheological Behavior of Chitosan-Grafted-Polyacrylamide in Aqueous Solution upon Heating

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 916
Author(s):  
Mengjie Wang ◽  
Yonggang Shangguan ◽  
Qiang Zheng
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Electron Microscope ◽  
Light Scattering ◽  
Shear Rate ◽  
Critical Value ◽  
Heating Process ◽  
Electrostatic Repulsion ◽  
Thickening Behavior ◽  
Protonation Degree

In this work, the transformation of chitosan-grafted-polyacrylamide (GPAM) aggregates in aqueous solution upon heating was explored by cryo-electron microscope (cryo-TEM) and dynamic light scattering (DLS), and larger aggregates were formed in GPAM aqueous solution upon heating, which were responsible for the thermo-thickening behavior of GPAM aqueous solution during the heating process. The heating initiates a transformation from H-bonding aggregates to a large-sized cluster formed by self-assembled hydrophobic chitosan backbones. The acetic acid (HAc) concentration has a significant effect on the thermo-thickening behavior of GPAM aqueous solution; there is a critical value of the concentration (>0.005 M) for the thermo-thickening of 10 mg/mL GPAM solution. The concentration of HAc will affect the protonation degree of GPAM, and affect the strength of the electrostatic repulsion between GPAM molecular segments, which will have a significant effect on the state of the aggregates in solution. Other factors that have an influence on the thermo-thickening behavior of GPAM aqueous solution upon heating were investigated and discussed in detail, including the heating rate and shear rate.

STUDIES ON CONTINUOUS ADSORPTION OF ACETIC ACID FROM AQUEOUS SOLUTION USING RICE HUSK ADSORBENT

2018 ◽  
Vol 14 (1) ◽  
pp. 42
Author(s):  
S. V. A. R. SASTRY ◽  
SRI ADIBATLA ANUSHA ◽  
S. VARUN ◽  
◽  
◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Rice Husk ◽  
Continuous Adsorption

Spontaneous Formation of Giant Phospholipid Vesicles

1988 ◽  
Vol 43 (11-12) ◽  
pp. 938-947 ◽  
Author(s):  
Rolf-M. Servuss
Keyword(s):  
Aqueous Solution ◽  
Light Microscopy ◽  
Fluid Phase ◽  
Significant Part ◽  
Phospholipid Vesicles ◽  
Electrostatic Repulsion ◽  
Giant Vesicles ◽  
Spontaneous Formation

The spontaneous formation of giant (diameter > 10 μm) vesicles from a number of phospholipids in excess aqueous solution has been studied by light-microscopy. Electrically neutral as well as charged phospholipids swell to form giant vesicles only if the lipids are in the fluid phase. This shows that electrostatic repulsion alone cannot explain the spontaneous formation of giant vesicles. The results confirm the suggestion that steric forces between extended membranes play a significant part in this process.

Acute Mercury Poisoning After Polyvinyl Alcohol Preservative Ingestion

PEDIATRICS ◽  
1980 ◽  
Vol 66 (1) ◽  
pp. 132-134
Author(s):  
James Seidel
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Polyvinyl Alcohol ◽  
Mercuric Chloride ◽  
Medical Center ◽  
Mercury Poisoning

Polyvinyl alcohol preservative (PVA) is used routinely in the laboratory for collection of specimens for examination for ova and parasites.1-4 PVA, presently used at Harbor-UCLA Medical Center, contains: 4.5% mercuric chloride, 5% polyvinyl alcohol, 30% denatured alcohol, 4.5% acetic acid, and 1.5% glycerin in an aqueous solution. The kit, as shown in the Figure, contains three bottles with 10-ml aliquots of PVA, wooden sticks for mixing the specimen, and written instructions for collection of the specimens. The bottles are clearly labeled as poison in English and Spanish, and specific verbal as well as written instructions are given to patients and their families when the ova and parasite kits are dispensed.

Protein cluster formation in aqueous solution in the presence of multivalent metal ions – a light scattering study

Soft Matter ◽  
2014 ◽  
Vol 10 (6) ◽  
pp. 894-902 ◽  
Author(s):  
Daniel Soraruf ◽  
Felix Roosen-Runge ◽  
Marco Grimaldo ◽  
Fabio Zanini ◽  
Ralf Schweins ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Light Scattering ◽  
Metal Ions ◽  
Cluster Formation ◽  
Protein Cluster ◽  
Scattering Study ◽  
Multivalent Metal

scholarly journals Antioxidant activity of Induna apple pomace extract

2005 ◽  
pp. 239-246 ◽  
Author(s):  
Sladjana Savatovic ◽  
Sonja Djilas ◽  
Vesna Tumbas ◽  
Jasna Canadanovic-Brunet ◽  
Gordana Cetkovic
Keyword(s):  
Aqueous Solution ◽  
Antioxidant Activity ◽  
Acetic Acid ◽  
Electron Spin Resonance ◽  
Hydroxyl Radicals ◽  
Electron Spin ◽  
Esr Spectroscopy ◽  
Methanol Extract ◽  
Apple Pomace ◽  
Spin Resonance

Different concentrations ofmethanol aqueous solution with or without 0.5% acetic acid and 80% acetone were used to achieve the highest yield of extraction of phenolics from Induna apple pomace. The highest content of phenolics (6.38 mg/g) was detected in the 80% methanol extract. The influence of 80% methanol extract of Induna apple pomace on stable l,l-diphenyl-2-picrylhydrazyl (DPPH) and reactive hydroxyl radicals has been investigated by electron spin resonance (ESR) spectroscopy. Based on the obtained results it can be concluded that the investigated extract is more effective in the DPPH test than on the DMPO-OH scavenging. In both cases antioxidant activity increased with increasing concentration of the investigated extract. The high contents ofphenolics (6.38 mg/g), flavonoids (1.01 mg/g) and flavan-3-ols (0.70 mg/g) in 80% methanol extract indicated that these compounds contributed to the antioxidant activity of Induna apple pomace.

Synthesis of ZrO2 Nanotubes by Anodization of Zr Foil

2015 ◽  
Vol 799-800 ◽  
pp. 125-129
Author(s):  
Mary Donnabelle L. Balela ◽  
April Alexa S. Lagarde ◽  
Stephen Jann A. Tamayo ◽  
Nikko S. Villareal ◽  
Ann Marielle Parreno
Keyword(s):  
Aqueous Solution ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Preparation ◽  
The Other ◽  
Preparation Methods ◽  
X Ray ◽  
Anodization Time ◽  
Other Hand ◽  
Scanning Electron

Zirconia (ZrO2) nanotubes were synthesized by anodization of zirconium (Zr) foil in NH4Fand (NH4)2SO4 aqueous solution. Different surface preparation methods (electropolishing and etching) were applied on the Zr foil prior to anodizaton. In addition, the anodization time and NH4F concentration were varied. The structure and morphologies of the nanotubes and their crystallinity were confirmed using scanning electron microscope and x-ray diffractometer, respectively. ZrO2 nanotubes with large diameters and thick walls were formed at lower NH4F concentration and longer anodization time. On the other hand, smaller nanotubes with thinner walls were produced when the NH4F concentration was increased. The synthesized nanotubes were predominantly tetragonal ZrO2 with small amounts of monoclinic ZrO2.

Determination of Plant Hormone Indole-3-Acetic Acid in Aqueous Solution

2012 ◽  
Vol 25 (1) ◽  
pp. 303-307 ◽  
Author(s):  
Jana Bulíčková ◽  
Romana Sokolová ◽  
Stefania Giannarelli ◽  
Beatrice Muscatello
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Plant Hormone ◽  
Indole 3 Acetic Acid
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