Effect of the hydrophilicity of the polymer matrix on immobilized α-chymotrypsin

1984 ◽  
Vol 49 (6) ◽  
pp. 1552-1556
Author(s):  
Minoru Kumakura ◽  
Isso Kaetsu
Keyword(s):  
Thermal Stability ◽  
Enzyme Activity ◽  
Pore Size ◽  
Polymer Matrix ◽  
Low Temperatures ◽  
Radiation Polymerization ◽  
Thermal Stability Of

α-Chymotrypsin was immobilized by radiation polymerization at low temperatures and the effect of the hydrophilicity of the polymer matrix on the enzyme activity and thermal stability was studied. The activity and thermal stability of immobilized chymotrypsin increased with the increasing hydrophilicity of the polymer matrix or monomer. The thermal stability was affected by the form and pore size of the polymer matrix; chymotrypsin immobilized on a soft-gel polymer matrix exhibited an enhanced thermal stability.

Thermal and viscoelastic behaviors of nanotube-reinforced polyethylene composite

2011 ◽  
Vol 1312 ◽  
Author(s):  
Ananta Raj Adhikari ◽  
Mircea Chipara ◽  
Karen Lozano
Keyword(s):  
Mechanical Property ◽  
Thermal Stability ◽  
Mechanical Behavior ◽  
Storage Modulus ◽  
Polymer Matrix ◽  
Loss Modulus ◽  
Polyethylene Composite ◽  
Viscoelastic Behaviors ◽  
Thermal Stability Of

ABSTRACTThe effect of processing (shear) time on the mechanical behavior and thermal stability of multiwalled nanotube reinforced polyethylene was investigated. It was observed that the mechanical property (storage modulus, loss modulus) of the composites is process dependant whereas the thermal stability does not. The increase in mechanical behavior is attributed to a stronger interface between the nanotube and the polymer matrix.

Immobilization of hemoglobin on stable mesoporous multilamellar silica vesicles and their activity and stability

2005 ◽  
Vol 20 (10) ◽  
pp. 2682-2690 ◽  
Author(s):  
Yufang Zhu ◽  
Weihua Shen ◽  
Xiaoping Dong ◽  
Jianlin Shi
Keyword(s):  
Thermal Stability ◽  
Pore Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Practical Applications ◽  
Silica Material ◽  
Transmission Electron ◽  
Mesoporous Support ◽  
Adsorption Desorption ◽  
Thermal Stability Of

A stable mesoporous multilamellar silica vesicle (MSV) was developed with a gallery pore size of about 14.0 nm. A simulative enzyme, hemoglobin (Hb), was immobilized on this newly developed MSV and a conventional mesoporous silica material SBA-15. The structures and the immobilization of Hb on the mesoporous supports were characterized with x-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, Fourier transform infrared, ultraviolet-visible spectroscopy, and so forth. MSV is a promising support for immobilizing Hb due to its large pore size and high Hb immobilization capacity (up to 522 mg/g) compared to SBA-15 (236 mg/g). Less than 5% Hb was leached from Hb/MSV at pH 6.0. The activity study indicated that the immobilized Hb retained most peroxidase activity compared to free Hb. Thermal stability of the immobilized Hb was improved by the proctetive environment of MSV and SBA-15. Such an Hb-mesoporous support with high Hb immobilization capacity, high activity, and enhanced thermal stability will be attractive for practical applications.

Effects of the Co-Presence of Conflicting Magnetic Anisotropy in Ba Ferrite Particles

2010 ◽  
Vol 67 ◽  
pp. 108-112
Author(s):  
Giancarlo Bottoni
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Low Temperatures ◽  
Magnetocrystalline Anisotropy ◽  
Shape Anisotropy ◽  
Recording Media ◽  
Magnetization Switching ◽  
Crystalline Anisotropy ◽  
Thermal Stability Of

In Ba ferrite particles magnetocrystalline and shape anisotropies are contemporarily present and conflicting. The strength and evolution of the two anisotropies are studied, through the dependence of the anisotropy constants on temperature. While in pure Ba ferrite particles the anisotropy is uniaxial at all temperatures, since the magnetocrystalline anisotropy clearly prevails on shape anisotropy, in particles modified for employment in recording media the two anisotropies are comparable and at low temperatures the shape anisotropy result stronger than the crystalline anisotropy. Besides the irregular shape of the particles introduces further preferred directions for the magnetization. The Co/Ti-doped particles show a multiple axes anisotropy. The macroscopic magnetic properties are found in relationship with the evolution of the anisotropy. Also the influence that the presence of such multiple anisotropy has on the magnetization switching and on the thermal stability of the magnetization of the Ba ferrite particles is analyzed.

Influence of ion exchange and calcination on pore size and thermal stability of MCM-41 with different Si/Al ratios

1998 ◽  
Vol 94 (6) ◽  
pp. 817-820 ◽  
Author(s):  
Heico Koch ◽  
Uwe Böhmer ◽  
Andreas Klemt ◽  
Wladimir Reschetilowski ◽  
Michael Stöcker
Keyword(s):  
Thermal Stability ◽  
Ion Exchange ◽  
Pore Size ◽  
Thermal Stability Of ◽  
Mcm 41

scholarly journals Antimicrobial Properties of Chitosan-Alumina/f-MWCNT Nanocomposites

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Monaheng Masheane ◽  
Lebea Nthunya ◽  
Soraya Malinga ◽  
Edward Nxumalo ◽  
Tobias Barnard ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Polymer Matrix ◽  
Antimicrobial Properties ◽  
Inversion Method ◽  
Bacterial Strains ◽  
Multiwalled Carbon ◽  
Simple Phase ◽  
Phase Inversion Method ◽  
Thermal Stability Of ◽  
Sem Analyses

Antimicrobial chitosan-alumina/functionalized-multiwalled carbon nanotube (f-MWCNT) nanocomposites were prepared by a simple phase inversion method. Scanning electron microscopy (SEM) analyses showed the change in the internal morphology of the composites and energy dispersive spectroscopy (EDS) confirmed the presence of alumina and f-MWCNTs in the chitosan polymer matrix. Fourier transform infrared (FTIR) spectroscopy showed the appearance of new functional groups from both alumina and f-MWCNTs, and thermogravimetric analysis (TGA) revealed that the addition of alumina and f-MWCNTs improved the thermal stability of the chitosan polymer. The presence of alumina and f-MWCNTs in the polymer matrix was found to improve the thermal stability and reduced the solubility of chitosan polymer. The prepared chitosan-alumina/f-MWCNT nanocomposites showed inhibition of twelve strains of bacterial strains that were tested. Thus, the nanocomposites show a potential for use as a biocide in water treatment for the removal of bacteria at different environmental conditions.

Thermal stability of retained austenite in Cr–Ni weld metals at low temperatures

2013 ◽  
Vol 29 (5) ◽  
pp. 594-597 ◽  
Author(s):  
H Qiu ◽  
J G Qi ◽  
L N Wang ◽  
F X Yin ◽  
K Hiraoka
Keyword(s):  
Thermal Stability ◽  
Low Temperatures ◽  
Retained Austenite ◽  
Weld Metals ◽  
Thermal Stability Of
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