Biodegradable Electrospun Fibers Containing the Compound Antihypertensive Drugs

2011 ◽  
Vol 332-334 ◽  
pp. 1218-1222 ◽  
Author(s):  
An Fang Wei ◽  
Juan Wang ◽  
Xue Qian Wang ◽  
Qu Fu Wei ◽  
Da Yin Hou
Keyword(s):  
Antihypertensive Drugs ◽  
Amorphous State ◽  
Heat Stability ◽  
Composite Fiber ◽  
Chemical Components ◽  
Composite Fibers ◽  
Biodegradable Composite ◽  
Ft Ir ◽  
Pure Drug ◽  
Better Than

In this study, the biodegradable composite fiber contained different ratios of the compound antihypertensive drugs were electrospun.The morphology, chemical components, heat stability of the composite fibers were investigated.The results showed the diameters of the composite fibers decreased and their distributions tended to be much evener with the increase of the compound antihypertensive drugs content. Fourier Transform Infrared (FT-IR) showed the chemical components of the compound antihypertensive drugs had not changed when it was electrospun into the composite fibers. DSC results showed that the drugs lost their intrinsic crystallization and existed in amorphous state in the composite fibers and the heat stability of the composite were better than the pure drug.

scholarly journals Morphology and Surface Properties of Poly (L-lactic acid)/Captopril Composite Nanofiber Membranes

2012 ◽  
Vol 7 (1) ◽  
pp. 155892501200700 ◽  
Author(s):  
Anfang Wei ◽  
Juan Wang ◽  
Xueqian Wang ◽  
Dayin Hou ◽  
Qufu Wei
Keyword(s):  
Lactic Acid ◽  
Composite Nanofibers ◽  
Chemical Components ◽  
Pore Width ◽  
Surface Areas ◽  
Composite Nanofiber ◽  
Mass Fractions ◽  
Ft Ir ◽  
Nanofiber Membranes ◽  
Better Than

In this study, Poly (L-lactic acid)/Captopril composite nanofiber membranes were electrospun for drug delivery. Different mass fractions of Poly (L-lactic acid), different ratios of Captopril and the influences of PEG4000 added in the spinning solution are discussed. The morphology, chemical components, the surface areas and pore sizes, wettability of the composite nanofiber membranes were investigated. The results showed that the diameters of the composite nanofibers increased with the increase of Poly (L-lactic acid) mass fractions, the diameters decreased with the increase of Captopril content as well as the addition of the surfactant. Fourier Transform Infrared (FT-IR) showed the chemical components of Captopril remained unchanged when it was electrospun into the composite nanofibers. The surface areas pore width and pore volume of the composite nanofibers became a little larger than those of poly (L-lactic acid) nanofibers, and the wettability of the composite nanofiber membranes was better than those of poly (L-lactic acid) nanofiber membranes. Wettability was improved by an increase of the drug load amount.

scholarly journals Preparation of metal doped quercetin nanoparticles, characterization and their stability study

2019 ◽  
Vol 8 (4) ◽  
pp. 704-710 ◽  
Keyword(s):  
Amorphous State ◽  
Stability Study ◽  
Acidic Condition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanoprecipitation Method ◽  
Ft Ir ◽  
Nanoparticles Characterization ◽  
Metal Doped ◽  
Better Than

The purpose of this study was to develop metal-loaded (Zn, Cu) quercetin nanoparticles (M-QNPs) using a nanoprecipitation method for the investigation of solubility and stability of QNPs and their metal doped NPs (M-QNPs) in acidic condition. The QNPs and M-QNPs were characterized by using UV-visible and FT-IR spectroscopy, X-ray diffraction, UPLC-DAD, scanning electron microscopy (SEM) and energy dispersive X-ray (EDAX) analysis. The XRD and SEM results of QNPs showed the conversion of the amorphous state of the drug to the crystalline state. The microscopic results demonstrate that the QNPs and M-QNPs showed rod shaped structure which ascribed to a different degree of solubility and stability. In conclusion, the metal doped QNPs improved its stability in acidic condition, but the solubility of M-QNPs was better than that of QNPs which could be used as trace elements supplement for micro-nutrient.

Preparation and Characrization of Tic/C Composite Fiber by Chemical Vapor Deposition

2012 ◽  
Vol 455-456 ◽  
pp. 935-938
Author(s):  
Hai Quan Wang
Keyword(s):  
Chemical Vapor Deposition ◽  
Carbon Fibers ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Composite Fiber ◽  
Composite Fibers ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Tic Particle ◽  
Higher Temperature

- TiC/C composite fibers were prepared by vapor phase titanizing of the regular carbon fibers via chemical vapor deposition (CVD). The carbon fibers were titanized from the surface of the fiber to the core. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were applied to characterize the morphology and structure of the TiC/C composite fibers. The influences of CVD reaction conditions such as temperature and reaction time on the TiC particle size and the thickness of the deposited layer were investigated. Higher temperature and longer time resulted in the growth of bigger size of the TiC crystal particles, and the particle uniformity was also decreased.

scholarly journals Starch-Based Fishing Composite Fiber and Its Degradation Behavior

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Wenwen Yu ◽  
Fei Yang ◽  
Lei Wang ◽  
Yongli Liu ◽  
Jiangao Shi
Keyword(s):  
Melt Spinning ◽  
Starch Content ◽  
Reactive Extrusion ◽  
Composite Fiber ◽  
Mechanical Analysis ◽  
Composite Fibers ◽  
Reactive Blending ◽  
Dynamic Mechanical ◽  
One Step ◽  
Β Relaxation

The starch-based fishing composite fibers were prepared by one-step reactive extrusion and melt spinning. The effects of starch contents on the microstructural, thermal, dynamic mechanical, and mechanical properties of starch-based composite fibers were studied. And the degradation behaviors in soil of the fibers were also investigated. The compatibility between starch and HDPE is improved significantly by grafting maleic anhydride (MA) using one-step reactive blending extrusion. As the starch content increased, the melting temperature and the crystallinity of the fibers gradually decreased due to fluffy internal structures. Dynamic mechanical analysis showed that the transition peak α in the high-temperature region was gradually weakened and narrowed with increasing starch content; moreover, a shoulder appeared on the low-temperature side of the α peak was assigned to the β-relaxation related to starch phase. In addition, the mechanical results showed the significant decrease in the breaking strength and increase in the elongation at break of the starch-based composite fibers as the starch content increased. After degradation in soil for 5 months, the surface of the composite fibers had been deteriorated, while flocculent layers were observed and a large number of microfibers appeared. And the weight loss rate of the starch-based composite fibers (5.2~34.8%) significantly increased with increasing starch content (50~90 wt%).

Study on Modified Rapeseed Oil/Montmorillonite Nanocomposites

2010 ◽  
Vol 123-125 ◽  
pp. 1291-1294 ◽  
Author(s):  
Bin Lü ◽  
Jian Zhong Ma ◽  
Dang Ge Gao ◽  
Lei Hong
Keyword(s):  
Rapeseed Oil ◽  
Fourier Transforms ◽  
Raw Materials ◽  
Infrared Spectrometry ◽  
Emulsifying Properties ◽  
X Ray Diffraction ◽  
Layer Spacing ◽  
Transmission Electron ◽  
Ft Ir ◽  
Better Than

Modified rapeseed oil(MRO) was prepared by using rapeseed oil, ethylene diamine and acrylic acid as the raw materials. Modified rapeseed oil/montmorillonite(MRO/MMT) nanocomposite was prepared by using modified rapeseed oil and montmorillonite. The emulsifying properties of MRO and MRO/MMT were determined respectively. Fourier transforms infrared spectrometry (FT-IR) and Transmission Electron microscope (TEM) results showed that MRO/MMT was prepared successfully. X-ray diffraction (XRD) results showed that modified rapeseed oil could smoothly enter the interlayer of montmorillonite, and modified the montmorillonite; with an increase in the amount of montmorillonite, the layer spacing of montmorillonite in the MRO/MMT lower after the first increase. The results of emulsifying properties indicated that emulsifying properties of MRO/MMT was better than MRO.

A Comparison of FT-IR/PA and FT-IR/PBD Spectra of Powders

1986 ◽  
Vol 40 (5) ◽  
pp. 636-641 ◽  
Author(s):  
P. G. Varlashkin ◽  
M. J. D. Low ◽  
G. A. Parodi ◽  
C. Morterra
Keyword(s):  
Probe Beam ◽  
Beam Deflection ◽  
Signal To Noise ◽  
Absorption Bands ◽  
Ir Radiation ◽  
Laser Probe ◽  
Ft Ir ◽  
Better Than

FT-IR photoacoustic (PA) and also photothermal beam deflection (PBD) spectra were recorded with the same particulate samples (graphite, charcoal, aspirin, and silica) under the same conditions in order to compare the quality of the spectra obtainable with the two techniques. A PA cell fitted with windows for the PBD laser probe beam was used, and PA and PBD spectra of each sample were recorded at 8 cm−1 resolution at each of the four different interferometer scan velocities. Although the overall aspects of FT-IR/PA and FT-IR/PBD spectra are the same, the signal-to-noise ratios of PA spectra are appreciably better than those of PBD spectra because PBD detection is more prone to disturbance by vibration than is PA detection. Absorption bands appear at the same wavenumbers in PA and PBD spectra. However, the relative intensities of bands of PBD spectra depend on the absorptive properties of the powdered solids; with weak absorbers, some bands may not be detected at all. PAS can be used with all powders. PBDS is of little or no use for the examination of weakly absorbing powders unless they scatter IR radiation extensively.

New Method of Preparation and Property Study of the Montmorillonite Modified with CTAB

2011 ◽  
Vol 284-286 ◽  
pp. 377-381
Author(s):  
Ji Chu Zhang ◽  
Ze Peng Zhang ◽  
Bo Hu ◽  
Gang Liu
Keyword(s):  
Contact Angle ◽  
Ammonium Bromide ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Hydrophobic Property ◽  
X Ray ◽  
Structure And Property ◽  
Organic Components ◽  
Ft Ir ◽  
Better Than

In this paper, Ca2+-montmorillonite (Ca2+-Mt) was modified with cationic surfactant hexadecyl trimethyl ammonium Bromide (CTAB) directly, without changing Ca2+-Mt into Na+-montmorillonite (Na+-Mt). X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), contact angle tests and rotary viscosity tests were used to characterize the structure and property of the organo-montmorillonite. The results of XRD show that interlayer space (d001) of the product is 4.05nm. The results of TGA indicate the ratio of weight loss of the organic components in the product is 37.7%. The results of FT-IR indicate there are organic components and hardly any water molecules in the product. All these findings indicate that the CTAB has intercalated into the galleries of Ca2+-Mt. Contact angle tests shows the product is well hydrophobic and the hydrophobic property is as good as that of organo-montmorillonite modified from Na+-Mt. Rotary viscosity tests show that the viscosity of the product at the rotational speed of 6R/min is 1226mPa·s, much better than that of the organo- montmorillonite modified from Na+-Mt which is 1070 mPa·s. The thixotropy index of the product is 9.22, much better than that of the organo-montmorillonite modified from Na+-Mt which is 5.88. It can be concluded that organo-montmorillonite with perfect interlayer expansion and thixotropic property was prepared by modifying Ca2+-Mt with CTAB directly.

Preparation of MgO–Y2O3 Composite Ceramic by Aqueous Gel Casting

2021 ◽  
Vol 16 (3) ◽  
pp. 444-451
Author(s):  
Liangwen Liu ◽  
Mu Zhang ◽  
Xing’an Wang ◽  
Xudong Sun
Keyword(s):  
Casting Process ◽  
Composite Ceramic ◽  
Ethanol Solution ◽  
Zeta Potentials ◽  
Gel Casting ◽  
Modification Process ◽  
Die Pressing ◽  
Ft Ir ◽  
Temperature And Pressure ◽  
Better Than

MgO–Y2O3 composite ceramics were prepared by gel-casting technology. The surface of MgO powder is passivated with H3PO4 ethanol solution. The treated powder can be dispersed in water with a dispersant. The powder surface modification process was verified by pH, Zeta potentials, Fourier transmission infrared absorption spectroscopy (FT-IR), the absorbance of suspension and rheological properties. The obtained stable suspensions were gel cast, dried, and sintered at 1400 °C for 30 min under 35 MPa. As a comparison, the powder was compressed by die pressing and sintered at the same temperature and pressure. After sintering, the MgO–Y2O3 composite ceramic with a theoretical density of 97.29% can be prepared by aqueous gel casting process. The properties of MgO–Y2O3 composite ceramic fabricated by gel casting are better than die pressing.

scholarly journals Electrospun PAN/MAPbI3 Composite Fibers for Flexible and Broadband Photodetectors

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 50 ◽  
Author(s):  
Gaolin Li ◽  
Zhenhua Jiang ◽  
Weilin Wang ◽  
Zengyong Chu ◽  
Ye Zhang ◽  
...  
Keyword(s):  
Optoelectronic Devices ◽  
Composite Fiber ◽  
Composite Fibers ◽  
Optical Gap ◽  
Perovskite Materials ◽  
Highly Sensitive ◽  
Improved Stability ◽  
Moisture Stability ◽  
Flexible Applications ◽  
Thermal Stability Of

Methylammonium lead triiodide perovskite (CH3NH3PbI3, MAPbI3) has been emerging as an easy processing and benign defect material for optoelectronic devices. Fiber-like perovskite materials are especially in demand for flexible applications. Here we report on a kind of polyacrylonitrile (PAN)/MAPbI3 composite fiber, which was electrospun from the mixing solution of PAN and MAPbI3. The absorption edge and optical gap of the PAN/MAPbI3 composite fibers can be easily tuned as the ratio of the perovskite changes. Both the moisture stability and the thermal stability of the perovskite are improved with the protection of PAN polymers. Flexible photodetectors based on this perovskite fiber were fabricated and analyzed. The photoresponse of the detector was highly sensitive to broadband visible light, and reached 6.5 μA W−1 at 700 nm with a voltage bias of 10 V. Compared with pure MAPbI3 photodetectors, this composite fiber photodetector has much-improved stability and flexibility, which can even be used to detect motion-related angular changes.

Stability of buffalo casein micelles

1979 ◽  
Vol 46 (2) ◽  
pp. 401-405 ◽  
Author(s):  
Nripendra C. Ganguli
Keyword(s):  
Sialic Acid ◽  
Gel Filtration ◽  
Skim Milk ◽  
Heat Stability ◽  
Casein Micelles ◽  
Heat Stable ◽  
Micellar Casein ◽  
Acid Release ◽  
The Stability ◽  
Better Than

SUMMARYBuffalo skim-milk is less heat stable than cow skim-milk. Interchanging ultracentrifugal whey (UCW) and milk diffusate with micellar casein caused significant changes in the heat stability of buffalo casein micelles (BCM) and cow casein micelles (CCM). Buffalo UCW dramatically destabilized COM, whereas buffalo diffu-sate with CCM exhibited the highest heat stability.Cow κ-casein stabilizes αs-casein against precipitation by Ca better than buffalo º-casein. About 90% of αs-casein could be stabilized by κ: αs ratios of 0·20 and 0·231 for cow and buffalo, respectively.Sialic acid release from micellar κ-casein by rennet was higher than from acid κ-casein in both buffalo and cow caseins, the release being slower in buffalo. The released macropeptide from buffalo κ-casein was smaller than that from cow κ-casein as revealed by Sephadex gel filtration.Sub-units of BCM have less sialic acid (1·57mg/g) than whole micelles (2·70mg/g). On rennet action, 47% of bound sialic acid was released from sub-units as against 85% from whole micelles. The sub-micelles are less heat stable than whole micelles. Among ions tested, added Ca reduced heat stability more dramatically in whole micelles, whereas added phosphate improved the stability of micelles and, more strikingly, of sub-micelles. Citrate also improved the heat stability of sub-micelles but not of whole micelles.

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