Effects of pH and temperature on colloidal properties and molecular characteristics of Konjac glucomannan

2015 ◽  
Vol 134 ◽  
pp. 285-292 ◽  
Author(s):  
Wenjie Jian ◽  
Ka-Chai Siu ◽  
Jian-Yong Wu
Keyword(s):  
Konjac Glucomannan ◽  
Molecular Characteristics ◽  
Colloidal Properties ◽  
Effects Of Ph

Adsorption of Cu(II) Ions from an Aqueous Solution by Cross-Linked Carboxymethyl Konjac Glucomannan

2011 ◽  
Vol 239-242 ◽  
pp. 2310-2316 ◽  
Author(s):  
Chun Mei Niu ◽  
Shao Ying Li ◽  
Dong Huang
Keyword(s):  
Adsorption Capacity ◽  
Copper Nitrate ◽  
Konjac Glucomannan ◽  
Ion Adsorption ◽  
Adsorption Time ◽  
Isotherm Equation ◽  
Langmuir Isotherm Equation ◽  
Effects Of Ph ◽  
The Relationship ◽  
Carboxymethyl Konjac Glucomannan

Crosslinked Carboxymethyl Konjac Glucomannan(CMKGM) with substitution degrees ofcarboxymethyl group（DS）0.265, 0.457 and 0.586 were prepared through reaction of monochloroacetic acid, konjac glucomannan(KGM) and epichlorohydrin and used to adsorb Cu(II) from the aqueous solutions of copper nitrate. The effects of pH, adsorbent dose, initial concentration of Cu(II), adsorption time and temperature on adsorption capacity were investigated. The results showed that adsorption capacity increased with an increasing DS of the carboxymethyl groups. Equilibrium adsorption time was 20 min or so and was independent on DS. The adsorption followed Langmuir isotherm equation. Ligand ion adsorption between carboxymethyl group and Cu(II) was thought to be predominate in the process of adsorption according to the relationship between DS and thermodynamic parameters. CMKGM can be used as cheaper and more effective adsorbents.

Study on Molecule Dimension of Different Granularity Konjac Glucomannan

2011 ◽  
Vol 52-54 ◽  
pp. 1344-1347
Author(s):  
Chao Wang ◽  
Yu Peng Zhu ◽  
Mei Xu ◽  
Dong Sheng Li ◽  
Hong Xia Huang
Keyword(s):  
Molecular Conformation ◽  
Laser Light ◽  
Linear Structure ◽  
Konjac Glucomannan ◽  
Theoretical Research ◽  
Molecular Characteristics ◽  
Practical Application ◽  
Molecular Dimension ◽  
Particle Size Analyzer ◽  
Granularity Distribution

In this paper, the relativity on the granularity with different mesh of konjac glucomannan (KGM) and molecular dimension was discussed. Laser particle size analyzer, laser light scattering and digital polarimeter were used to analyze the granularity distribution, molecular characteristics and polarity of KGM. The results showed that the granularity of KGM after gradient refining was gradually decreased and KGM was well dispersed in ethanol(D50=13.11μm).The Mw of KGM was gradually decreased with its granularity decrease and its molecular conformation was from globular to linear structure. The space asymmetry of KGM at 80-100 meshes was minimum and its polarity was maximum. The primary establishment on the relativity offered the references to KGM theoretical research and practical application.

Flexibility Modification of KGM Membranes by Maleic Anhydride

2009 ◽  
Vol 620-622 ◽  
pp. 627-630 ◽  
Author(s):  
Yan Chen ◽  
Xue Gang Luo ◽  
Xiao Yan Lin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Maleic Anhydride ◽  
Processing Parameters ◽  
Konjac Glucomannan ◽  
Optimum Conditions ◽  
Orthogonal Experiments ◽  
Folding Endurance ◽  
Effects Of Ph

Konjac Glucomannan (KGM) was modified by maleic anhydride (MA). The influences of processing parameters on the mechanical properties of KGM films were investigated through orthogonal experiments. The results showed that the effects of pH, temperature and time of KGM swelling on tensile strength and folding endurance of modified KGM membranes were insignificant (F<F0.05). The quantity of MA affected slightly on the tensile strength (F<F0.05), but its effect on the folding endurance was significant (F>F0.01). Folding endurance and tensile strength of KGM membranes could be improved by proper addition of MA. The optimum conditions of KGM modification were that the mixture of KGM and MA was swelling at pH 4.0 and 60°C for 2 h, and then cast on a flat and dried at 50°C to give modified KGM membranes.

Electron microscopy of crystalline structure in thermotropic random copolymers

1991 ◽  
Vol 49 ◽  
pp. 1054-1055
Author(s):  
Afzana Anwer ◽  
S. Eilidh Bedford ◽  
Richard J. Spontak ◽  
Alan H. Windle
Keyword(s):  
Electron Microscopy ◽  
Crystalline Structure ◽  
Liquid Crystalline ◽  
Elevated Temperatures ◽  
Random Copolymers ◽  
Molecular Characteristics ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Identical Monomer ◽  
Periodic Layer

Random copolyesters composed of wholly aromatic monomers such as p-oxybenzoate (B) and 2,6-oxynaphthoate (N) are known to exhibit liquid crystalline characteristics at elevated temperatures and over a broad composition range. Previous studies employing techniques such as X-ray diffractometry (XRD) and differential scanning calorimetry (DSC) have conclusively proven that these thermotropic copolymers can possess a significant crystalline fraction, depending on molecular characteristics and processing history, despite the fact that the copolymer chains possess random intramolecular sequencing. Consequently, the nature of the crystalline structure that develops when these materials are processed in their mesophases and subsequently annealed has recently received considerable attention. A model that has been consistent with all experimental observations involves the Non-Periodic Layer (NPL) crystallite, which occurs when identical monomer sequences enter into register between adjacent chains. The objective of this work is to employ electron microscopy to identify and characterize these crystallites.

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

Effects of pH on proton transport by vacuolar pumps from maize roots

1992 ◽  
Vol 86 (1) ◽  
pp. 63-70 ◽  
Author(s):  
David Brauer ◽  
DeNea Conner ◽  
Shu-I Tu
Keyword(s):  
Proton Transport ◽  
Maize Roots ◽  
Effects Of Ph

DIP quality influenced by process water quality

TAPPI Journal ◽  
2014 ◽  
Vol 13 (9) ◽  
pp. 51-60
Author(s):  
DENNIS VOSS ◽  
HANS-JOACHIM PUTZ ◽  
SAMUEL SCHABEL
Keyword(s):  
Water Quality ◽  
Surface Tension ◽  
Ph Value ◽  
Water Hardness ◽  
Process Water ◽  
Test Results ◽  
Negative Effects ◽  
Water Parameters ◽  
Effects Of Ph ◽  
Contamination Levels

The need for deinking mills to reduce their fresh water consumption has resulted in higher loads of various contaminants in the process water. Lower recovered paper quality also leads to higher contamination levels in the mills. This higher load has an influence on achievable target brightness. The objective of the work was to determine and explain the main reasons for relatively poor deinked pulp quality or poor deinking potential based on the influence of recovered paper composition and process water quality. The process water parameters significantly affect the deinking potential of recovered paper. The test results showed the negative effects of increased water hardness. For standard recovered paper mixtures, flotation selectivity is higher with increasing flotation pH-value. Good results were realized for standard recovered paper with low hardness, low surface tension, and high pH-value. The results for recovered paper containing flexo newsprint could be slightly improved with low hardness, low surface tension, and low pH-value. The results of the test program using design of experiments showed interacting effects of pH-value and surface tension on luminosity and flotation selectivity.

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