Formation of Supramolecular Assemblies by Modulating Self-Assembling Properties of Diacetylenic Phosphocholines

2001 ◽  
Vol 707 ◽  
Author(s):  
Alok Singh ◽  
Eva M. Wong ◽  
Mark S. Spector ◽  
Joel M. Schnur
Keyword(s):  
Lipid Concentration ◽  
Morphological Transformation ◽  
Lipid Mixture ◽  
Practical Applications ◽  
Spectral Signatures ◽  
Self Assembling ◽  
Effects Of Temperature ◽  
Different Diameters ◽  
Circular Dichroic ◽  
Thermal Stability Of

ABSTRACTDiacetylenic phospholipid dispersions in water produce tubules (500 nm diameter) and helices from their initial vesicular morphology as a function of temperature and concentration. A binary mixture consisting of diacetylenic phospholipid, 1,2 bis (tricosa-10, 12-diynoyl)-sn-glycero-3-phosphocholine and a short chain phospholipid, 1,2-dinonanoyl –sn-glycero-3-phosphocholine was studied to explore the morphological transformation of lipids into tubules to develop an approach to control and produce tubules of different diameters. Circular dichroic spectra not only indicated the chiral nature of these tubules, but also provided distinct spectral signatures differentiating micro- and nanotubules. The effects of temperature and lipid concentration on the formation and stability of tubules were also explored. An equimolar lipid mixture provided structures with uniform morphology, which were stable for several hours up to 36°C. The thermal stability of nanotubules makes them an attractive candidate for many practical applications including controlled release technology.

Formation of Supramolecular Assemblies by Modulating Self-Assembling Properties of Diacetylenic Phosphocholines

2001 ◽  
Vol 711 ◽  
Author(s):  
Alok Singh ◽  
Eva M. Wong ◽  
Mark S. Spector ◽  
Joel M. Schnur
Keyword(s):  
Lipid Concentration ◽  
Morphological Transformation ◽  
Lipid Mixture ◽  
Practical Applications ◽  
Spectral Signatures ◽  
Self Assembling ◽  
Effects Of Temperature ◽  
Different Diameters ◽  
Circular Dichroic ◽  
Thermal Stability Of

ABSTRACTDiacetylenic phospholipid dispersions in water produce tubules (500 nm diameter) and helices from their initial vesicular morphology as a function of temperature and concentration. A binary mixture consisting of diacetylenic phospholipid, 1, 2 bis (tricosa-10, 12-diynoyl)-sn-glycero-3-phosphocholine and a short chain phospholipid, 1, 2-dinonanoyl -sn-glycero-3-phosphocholine was studied to explore the morphological transformation of lipids into tubules to develop an approach to control and produce tubules of different diameters. Circular dichroic spectra not only indicated the chiral nature of these tubules, but also provided distinct spectral signatures differentiating micro- and nanotubules. The effects of temperature and lipid concentration on the formation and stability of tubules were also explored. An equimolar lipid mixture provided structures with uniform morphology, which were stable for several hours up to 36 °C. The thermal stability of nanotubules makes them an attractive candidate for many practical applications including controlled release technology.

High partial thermal conductivity of luminescence sites: a crucial factor for reducing the heat-induced lowering of the luminescence efficiency

2021 ◽  
Author(s):  
Ni Luo ◽  
Jing Xu ◽  
Xiyue Cheng ◽  
ZhenHua Li ◽  
Yidong Huang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Practical Applications ◽  
Good Thermal Stability ◽  
The Past ◽  
Luminescence Efficiency ◽  
Thermal Stability Of

The good thermal stability of a phosphor is crucial for its practical applications. Unfortunately, in the past decades, only Gurney-Mott equation was available to describe the relation between the luminescence...

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.

Synthesis, Morphology and Photophysical Properties of Rod-Coil Copolymers

2009 ◽  
Vol 79-82 ◽  
pp. 2095-2098
Author(s):  
Yang Yen Yu ◽  
Wen Chen Chien ◽  
Chung Yi Hsu
Keyword(s):  
Photophysical Properties ◽  
Mixed Solvents ◽  
Blue Shift ◽  
Morphological Transformation ◽  
Good Thermal Stability ◽  
Lamellar Morphology ◽  
Long Rod ◽  
Spherical Micelles ◽  
Large Compound ◽  
Thermal Stability Of

The synthesis, morphology, and photophysical properties of poly[2,7-(9,9- dihexylfluorene)]-block-poly(2-vinyl pyridine) (PF-b-P2VP) with different coil lengths in mixed solvents of THF/methanol are reported. A flakes-like lamellar morphology is observed at a short coil length of PF-b-P2VP. As the coil length increases, a spherical and large compound micelle is formed. Upon further increase of the coil length, the morphological transformation from spherical micelles to long rod-like structures is observed. TGA results indicate a good thermal stability of the prepared copolymers. The spectra of optical absorption for the PF-b-P2VP in solution have a blue shift when the fraction of methanol in the mixed solvent increases. The present study shows that the significance of the rod/coil ratio and selective solvent content on the aggregate morphologies and photophysical properties of the rod-coil block copolymers.

Effects of Temperature Rise on the Flow of a Viscous Liquid through a Concentric Annulus with an Inner Cylinder Rotating

1964 ◽  
Vol 6 (3) ◽  
pp. 258-263 ◽  
Author(s):  
L. A. Newbery
Keyword(s):  
Exact Solution ◽  
Viscous Liquid ◽  
Temperature Rise ◽  
Forced Flow ◽  
Fluid Temperature ◽  
Practical Applications ◽  
Concentric Annulus ◽  
Effects Of Temperature

An exact solution is presented for the forced flow of a viscous liquid through a concentric annulus in which the fluid temperature is increased and the viscosity decreased by rotation of the inner boundary. Such a solution has not previously appeared in the published literature. Some practical applications are mentioned.

Thermal Stability of Moniliformin at Varying Temperature, pH, and Time in an Aqueous Environment†

2000 ◽  
Vol 63 (11) ◽  
pp. 1598-1601 ◽  
Author(s):  
GRACIELA PINEDA-VALDES ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Animal Species ◽  
Keshan Disease ◽  
Aqueous Environment ◽  
Buffer Solutions ◽  
Processing Times ◽  
Effects Of Temperature ◽  
The Stability ◽  
Increasing Temperature ◽  
Major Reduction ◽  
Thermal Stability Of

Moniliformin (MON) is a widely occurring mycotoxin, produced mainly by Fusarium proliferatum and Fusarium subglutinans in corn, that has been shown to be acutely toxic for various animal species and is a suspected cause of Keshan disease in China. The effects of temperature (100, 125, and 150°C) and pH (4, 7, and 9) on the stability of MON were determined in aqueous buffer solutions at processing times ranging from 10 to 60 min. The percentage of MON reduction was positively related to increasing temperature and pH. MON was most stable at pH 4. After 60 min at pH 4 and 150°C, MON was reduced by only 5%. Heating at pH 10 caused major reduction of MON. After 60 min at pH 10 and 100, 125, and 150°C, MON was reduced by 56, 72, and 83%, respectively. One trial done at 175°C and pH 10 showed that less than 1% MON remained after 60 min of processing.

Effects of Temperature, End-Conditions, Flow, and Branching on the Frequency Response of Pneumatic Lines

1972 ◽  
Vol 94 (1) ◽  
pp. 15-20 ◽  
Author(s):  
M. E. Franke ◽  
A. J. Malanowski ◽  
P. S. Martin
Keyword(s):  
Frequency Response ◽  
Experimental Results ◽  
Distributed Parameter ◽  
Transmission Line Theory ◽  
Amplitude Frequency Response ◽  
End Conditions ◽  
Line Theory ◽  
Effects Of Temperature ◽  
Different Diameters ◽  
Signal Sinusoïdal

Experimental results are presented to show the effects of temperature, flow, end-conditions, and branching on the small-signal sinusoidal amplitude frequency response of pneumatic lines. Distributed parameter transmission line theory for uniform lines is extended to include varying conditions of pressure and temperature along the line as well as series-connected lines of different diameters and parallel branching. The experimental results are compared with the formulated theory for several test configurations. Agreement between experiment and computer solutions based on the theory is relatively good.

THE EFFECTS OF TEMPERATURE UPON PANCREATIC AMYLASE IN SELECTED REPTILES AND AN AMPHIBIAN

1967 ◽  
Vol 45 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Yvette Abrahamson ◽  
Michael Maher
Keyword(s):  
Thermal Stability ◽  
Amylase Activity ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Pancreatic Amylase ◽  
Optimum Temperature ◽  
Preferred Temperatures ◽  
Effects Of Temperature ◽  
Subcellular Level ◽  
Thermal Stability Of

The effect of temperature on pancreatic amylase was studied on three species of reptiles and one amphibian. Pancreata were removed from the animals, homogenized, and assayed for amylase activity by the Caraway procedure. Assays were conducted at various temperatures to determine the optimum temperature of activity and the maximum temperature for thermal stability of pancreatic amylase. It appears that between reptiles and amphibians, and also among species of reptiles, there are thermally dependent differences at the subcellular level which are similar to the differences in the preferred temperatures of the animals.

scholarly journals Photoelectrical properties investigated on individual Si nanowires and their size dependence

2020 ◽  
Author(s):  
Xiaofeng Hu ◽  
Shujie Li ◽  
Zuimin Jiang ◽  
Xinju Yang
Keyword(s):  
Barrier Height ◽  
Size Dependence ◽  
Laser Intensity ◽  
Electrostatic Force ◽  
Si Nanowires ◽  
Practical Applications ◽  
Force Microscopy ◽  
Photoelectrical Properties ◽  
Atomic Force ◽  
Different Diameters

Abstract Periodically ordered arrays of vertically aligned Si nanowires (Si NWs) are successfully fabricated with controllable diameters and lengths. Their photoconductive properties are investigated by photoconductive atomic force microscopy (PCAFM) on individual nanowires. The results show that the photocurrent of Si NWs increases significantly with the laser intensity, indicating that Si NWs have good photoconductance and photoresponse capability. This photo-enhanced conductance can be attributed to the photo-induced Schottky barrier change, confirmed by I-V curve analyses. On the other hand, electrostatic force microscopy (EFM) results indicate that a large number of photo-generated charges are trapped in Si NWs under laser irradiation, leading to the lowering of barrier height. Moreover, the size dependence of photoconductive properties is studied on Si NWs with different diameters and lengths. It is found that the increasing magnitude of photocurrent with laser intensity is greatly relevant to the nanowires’ diameter and length. Si NWs with smaller diameters and shorter lengths display better photoconductive properties, which agrees well with the size-dependent barrier height variation induced by photo-generated charges. With optimized diameter and length, great photoelectrical properties are achieved on Si NWs. Overall, in this study the photoelectrical properties of individual Si NWs are systematically investigated by PCAFM and EFM, providing important information for the optimization of nanostructures for practical applications.

Sign in / Sign up

Export Citation Format

Share Document