Melting Behavior in Granular Metal Thin Films

1990 ◽  
Vol 195 ◽  
Author(s):  
Karl M. Unruh ◽  
B.M. Patterson ◽  
S.I. Shah
Keyword(s):  
Particle Size ◽  
Melting Temperature ◽  
Average Particle Size ◽  
Melting Behavior ◽  
Multilayer Films ◽  
Relative Reduction ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Metal Thin Films ◽  
Solid Liquid

ABSTRACTGranular metal films consisting of small Sn, Bi, and Pb particles, typically from less than 100 Å to several 1000 Å in size and embedded in a SiO2 matrix, have been fabricated over a range of metal compositions by RF sputter deposition. Two different film geometries have been prepared, homogeneous films and multilayer films consisting of alternating layers of granular metal and SiO2. These films have been characterized by x-ray diffraction and transmission electron microscopy and their melting behavior studied by differential scanning calorimetry. As the concentration of the metal component is decreased, the average particle size decreases and the particle size distribution becomes more narrow. When the solid-liquid transition is studied, the melting temperature has been found to be increasingly depressed as the particle size is reduced. In the smallest particles the relative reduction in the melting temperature is greater than 10 percent. No strong evidence for melting point enhancements, due to pressureeffects arising from the different thermal expansions of the metal particles and the SiO2 matrix, has been observed in either the homogeneous or multilayer films.

Synthesis of Emulsion for Water-Based Pigment Ink Jet

2011 ◽  
Vol 380 ◽  
pp. 81-84
Author(s):  
Li Ming Zhang ◽  
Xiu Lan Xin ◽  
Wei Jiang
Keyword(s):  
Particle Size ◽  
Water Resistance ◽  
Average Particle Size ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Reactive Surfactant ◽  
Potential Value ◽  
Ink Jet ◽  
Water Based ◽  
Pigment Ink

The water-based pigment ink jet emulsion whose particle size was less than 100nm was synthesized by the polymerization of methyl methacrylate, butyl acrylate and ethylhexyl acrylate, and anionic reactive surfactant and nonionic surfactant were used as the emulsifiers. The effects of particle size and water resistance were studied. The glass transition temperature was tested by differential scanning calorimetry. The average particle size of emulsion was range from 60nm to70nm, zeta potential value was less than -60mv; viscosity was 3.5mps; water absorption was 5.9%.

Effect of Core/Shell Ratio on Performance of Paraffin/Polyurea Phase Change Microencapsules

2014 ◽  
Vol 556-562 ◽  
pp. 32-35 ◽  
Author(s):  
Wu Sheng Luo ◽  
Sheng Fei Yu ◽  
Jie Min Zhou
Keyword(s):  
Particle Size ◽  
Phase Change ◽  
Interfacial Polymerization ◽  
Average Particle Size ◽  
Energy Performance ◽  
Toluene Diisocyanate ◽  
Core Shell ◽  
Average Particle ◽  
Mass Ratio ◽  
Solid Liquid

In this paper, paraffin/polyurea (PU) phase change microencapsules were prepared through an interfacial polymerization method using composite paraffin with solid/liquid mass ratio 3:7 as core materials, 2,4 toluene diisocyanate (TDI) and ethylenediamine (EDA) as monomers, NP-10 as an emulsifier. It was explored the effect of the monomer mass ratio mEDA: mTDIon the yield of hollow PU microcapsules, and the effect of core/shell ratio on the particle size and coating efficiency and storage-energy performance of paraffin/PU phase change microencapsules. The experimental results showed the PU yield is increasing with the increasing of EDA:TDI mass ratio until 0.5:1,then keeps the constant. Paraffin/PU phase change microencapsules prepared with the core-shell ratio of 2:1 have better performance: the melting point of 28.1°C, the enthalpy of 58.4KJ/Kg, encapsulation efficiency of 87.5%, the average particle size of 4.32μm, and the uniform particle size distribution.

scholarly journals Physicochemical, Digestive, and Sensory Properties of Panax Notoginseng Saponins Encapsulated by Polymerized Whey Protein

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2942
Author(s):  
Zengjia Zhou ◽  
Xiaomeng Sun ◽  
Jianjun Cheng ◽  
Qingfeng Ban ◽  
Mingruo Guo
Keyword(s):  
Particle Size ◽  
Whey Protein ◽  
Functional Foods ◽  
Average Particle Size ◽  
Panax Notoginseng ◽  
Intermolecular Forces ◽  
Sensory Properties ◽  
Average Particle ◽  
Panax Notoginseng Saponins ◽  
Scanning Calorimetry

Panax Notoginseng Saponins (PNS) may be beneficial to human health due to their bioactive function. The application of PNS in functional foods was limited due to the bitter taste and low oral bioavailability. PNS were encapsulated by polymerized whey protein (PWP) nanoparticles. The physicochemical, digestive, and sensory properties of the nanoparticles were investigated. Results showed that the nanoparticles had a particle size of 55 nm, the zeta potential of −28 mV, and high PNS encapsulation efficiency (92.94%) when the mass ratio of PNS to PWP was 1:30. Differential Scanning Calorimetry (DSC) results revealed that PNS were successfully encapsulated by PWP. The mainly intermolecular forces between PNS and PWP were hydrogen bonding and electrostatic attraction confirmed by Fourier Transform Infrared Spectroscopy (FTIR). Results of simulated gastrointestinal digestion indicated that the PNS-PWP (1:30) nanoparticles had smaller average particle size (36 nm) after treatment with gastric fluids and increased particle size (75 nm) after treatment with intestinal fluids. Transmission Electron Microscopy (TEM) micrographs reflected that the nanoparticles had irregular spherical structures. The encapsulated PNS exhibited significantly (p < 0.05) decreased bitterness compared to the non-encapsulated PNS confirmed by the electronic tongue. The results indicated that encapsulation of PNS with PWP could facilitate their application in functional foods.

Formulation and Characterization of Nateglinide Nanosuspension by Precipitation Method

2014 ◽  
Vol 7 (4) ◽  
pp. 2685-2691
Author(s):  
Amruta Papdiwal ◽  
Kishor Sagar ◽  
Vishal Pande
Keyword(s):  
Particle Size ◽  
Dissolution Rate ◽  
Water Solubility ◽  
Average Particle Size ◽  
Biologically Active ◽  
In Vitro Dissolution ◽  
Precipitation Method ◽  
Average Particle ◽  
Scanning Calorimetry

Poor water solubility and slow dissolution rate are major issues for the majority of upcoming and existing biologically active pharmaceutical compounds. Nateglinide is Biopharmaceutical Classification System Class-II drug that has low solubility and high permeability. The purpose of the present study was to improve the solubility and dissolution rate of Nateglinide by the preparation of nanosuspension by the nanoprecipitation technique. Nateglinide nanosuspension was evaluated for its particle size, in vitro dissolution study, and characterized by differential scanning calorimetry and scanning electron microscopy. The optimized formulation showed an average particle size of 207 nm and zeta potential of -25.8 mV. The rate of dissolution of the optimized nanosuspension was enhanced by 83% in 50 min relative to micronized suspension of nateglinide (37% in 50 min). This improvement was mainly due to the formulation of nanosized particles of Nateglinide. Stability study revealed that nanosuspension was more stable at room temperature and refrigerator condition with no significant change in particle size distribution. These results indicate that the nateglinide loaded nanosuspension may significantly improve in vitro dissolution rate and thereby possibly enhance the onset of therapeutic effect.

Synthesis and Characterization of Polyimide/Silica Nanocomposites

2011 ◽  
Vol 311-313 ◽  
pp. 96-100
Author(s):  
Jian Li Cheng ◽  
Cun Zhou ◽  
Hao Peng ◽  
Huan Wang ◽  
Yu Sun
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Amic Acid ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Silica Nanocomposites ◽  
Transmission Electron ◽  
Size Of Particles

Two kind of polyimide/silica nanocomposites which were recorded poly(amic acid)/ silica(PAA/SiO2) and SiO2in poly(amic acid) ammonium salt(PAS/SiO2) respectively, have been prepared for different methods. The size of SiO2in PAA/SiO2and PAS/SiO2are measured by Particle size analysis and the average particle size are 377nm and 53.7nm. Transmission electron microscopy(TEM) images of PAS/ SiO2confirm that the size of particles are ranged from 40 to 80nm. The stuctures of samples have been characterized by FT-IR spectra. The thermal stability of PAA/SiO2and PAS/SiO2are studied by thermogravimetric analysis (TGA) and the thermal behaviors were investigated by differential scanning calorimetry (DSC) in this paper. It is shown that PAA/SiO2have slightly better thermal properties than that of PAS/SiO2. The results obtained from Instron universal strength tester present the water-solube PAS/SiO2own the excellent mechanical prperties as same as PAA/SiO2.

Development of the Process of Pseudo-Ligatures Manufacturing from Aluminum and Nickel Powders for the Modification of Alloys

2014 ◽  
Vol 698 ◽  
pp. 452-456 ◽  
Author(s):  
Ekaterina A. Nosova ◽  
Antonina A. Kuzina ◽  
Anna V. Kuts
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Melting Temperature ◽  
Specific Surface Area ◽  
Aluminum Powder ◽  
Nickel Powder ◽  
Average Particle Size ◽  
Average Particle ◽  
Powder Sintering

Compacting after pressing and sintering of briquettes made from an aluminum powder with an average particle size from 50 to 150 microns, the specific surface area Ssp=0.26 m2/g and a nickel powder with an average particle size from 25 to 100 microns, the specific surface area Ssp= 0.03 m2/g has been investigated. Pressing load varied from 15 to 25 MPa for the aluminum powder and from 20 to 45 MPa for the nickel powder. Sintering of aluminum powder briquettes was carried out at temperatures (0.5-0.83) of melting temperature, (0.3-0.46) of melting temperature from the nickel powder. It is shown that the application of high pressure, low temperatures and short time makes it possible to receive pseudo-ligatures from an aluminum powder with porosity about 32% and a nickel powder with porosity about 30%.

scholarly journals Statistical optimization of dithranol-loaded solid lipid nanoparticles using factorial design

2011 ◽  
Vol 47 (3) ◽  
pp. 503-511 ◽  
Author(s):  
Makarand Suresh Gambhire ◽  
Mangesh Ramesh Bhalekar ◽  
Vaishali Makarand Gambhire
Keyword(s):  
Particle Size ◽  
Factorial Design ◽  
Solid Lipid Nanoparticles ◽  
Ex Vivo ◽  
Average Particle Size ◽  
Entrapment Efficiency ◽  
Lipid Nanoparticles ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Solid Lipid

This study describes a 3² full factorial experimental design to optimize the formulation of dithranol (DTH) loaded solid lipid nanoparticles (SLN) by the pre-emulsion ultrasonication method. The variables drug: lipid ratio and sonication time were studied at three levels and arranged in a 3² factorial design to study the influence on the response variables particle size and % entrapment efficiency (%EE). From the statistical analysis of data polynomial equations were generated. The particle size and %EE for the 9 batches (R1 to R9) showed a wide variation of 219-348 nm and 51.33- 71.80 %, respectively. The physical characteristics of DTH-loaded SLN were evaluated using a particle size analyzer, differential scanning calorimetry and X-ray diffraction. The results of the optimized formulation showed an average particle size of 219 nm and entrapment efficiency of 69.88 %. Ex-vivo drug penetration using rat skin showed about a 2-fold increase in localization of DTH in skin as compared to the marketed preparation of DTH.

scholarly journals Casein Micelles as Nanocarriers for Benzydamine Delivery

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4357
Author(s):  
Nikolay Zahariev ◽  
Maria Marudova ◽  
Sophia Milenkova ◽  
Yordanka Uzunova ◽  
Bissera Pilicheva
Keyword(s):  
Particle Size ◽  
Encapsulation Efficiency ◽  
Drug Loading ◽  
Average Particle Size ◽  
Crosslinking Agent ◽  
Morphological Characteristics ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Casein Micelles ◽  
Fourier Transformed Infrared Spectroscopy

The aim of the present work was to optimize the process parameters of the nano spray drying technique for the formulation of benzydamine-loaded casein nanoparticles and to investigate the effect of some process variables on the structural and morphological characteristics and release behavior. The obtained particles were characterized in terms of particle size and size distribution, surface morphology, production yield and encapsulation efficiency, drug-polymer compatibility, etc., using dynamic light scattering, scanning electron microscopy, differential scanning calorimetry, and Fourier transformed infrared spectroscopy. Production yields of the blank nanoparticles were significantly influenced by the concentration of both casein and the crosslinking agent. The formulated drug-loaded nanoparticles had an average particle size of 135.9 nm to 994.2 nm. Drug loading varied from 16.02% to 57.41% and the encapsulation efficiency was in the range 34.61% to 78.82%. Our study has demonstrated that all the investigated parameters depended greatly on the polymer/drug ratio and the drug release study confirmed the feasibility of the developed nanocarriers for prolonged delivery of benzydamine.

Synthesis of Styrene-Acrylic Emulsion for Aqueous Glazing Agent

2011 ◽  
Vol 380 ◽  
pp. 11-14
Author(s):  
Kun Chen ◽  
Xiu Lan Xin ◽  
Ya Na Wei
Keyword(s):  
Particle Size ◽  
Water Resistance ◽  
Average Particle Size ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Acrylic Emulsion ◽  
Reactive Surfactant ◽  
Potential Value ◽  
Ink Jet ◽  
Pigment Ink

The water-based pigment ink jet emulsion whose particle size was less than 100nm was synthesized by the polymerization of methyl methacrylate, butyl acrylate and ethylhexyl acrylate, and anionic reactive surfactant and nonionic surfactant were used as the emulsifiers. The effects of particle size and water resistance were studied. The glass transition temperature was tested by differential scanning calorimetry. The average particle size of emulsion was range from 60nm to70nm, zeta potential value was less than -60mv; viscosity was 3.5mps; water absorption was 5.9%.

scholarly journals Optimization of Extraction of Anthocyanins from Roselle (Hibiscus sabdariffa var. sabdariffa) in Aqueous Medium

2013 ◽  
Vol 6 ◽  
pp. 69-72 ◽  
Author(s):  
Chanendra Gartaula ◽  
Dhan Bahadur Karki
Keyword(s):  
Particle Size ◽  
Aqueous Medium ◽  
Average Particle Size ◽  
Average Particle ◽  
Anthocyanin Content ◽  
Extraction Temperature ◽  
Hibiscus Sabdariffa ◽  
Liquid Ratio ◽  
Total Anthocyanin ◽  
Solid Liquid

The dried roselle (Hibiscus sabdariffa var. sabdariffa) calyces were studied for the extraction of anthocyanin in aqueous solution. The total anthocyanin content in dried roselle powder was found to be 310.48mg/100g of dry matter. The extraction temperature at 70°C gave the highest yield (66.69-70.61%), while at 90°C the degradation of anthocyanins occurred. The solid-liquid ratio revealed no significant effect (p>0.05), whereas the particle size showed a significant effect (p<0.05) on the extraction of anthocyanin. The yields of anthocyanin extraction for 300 and 600 μm particle powders were significantly higher (p<0.5) than that of 1180μm powder. Reduction in the particle size inversely increased the yield of anthocyanins. In conclusion, the extraction of anthocyanin from dried roselle calyces with an average particle size of 600μm using a solid-liquid ratio of 1:50 in aqueous medium with pH 7.0 at 70°C for 20min showed the maximum yield (69.84%). J. Food Sci. Technol. Nepal, Vol. 6 (66-72), 2010 DOI: http://dx.doi.org/10.3126/jfstn.v6i0.8263

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