scholarly journals Multicore expandable microbubbles: Controlling density and expansion temperature

Polymer ◽  
2016 ◽  
Vol 90 ◽  
pp. 45-52 ◽  
Author(s):  
Natalia V. Lebedeva ◽  
Samuel N. Sanders ◽  
Maria Ina ◽  
Aleksandr P. Zhushma ◽  
Sean D. Olson ◽  
...  
2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Linjing Zhu ◽  
Hongqiao Lan ◽  
Bingjing He ◽  
Wei Hong ◽  
Jun Li

Encapsulation of menthol in beeswax was prepared by a modified particles from gas-saturated solutions (PGSS) process with controlling the gas-saturated solution flow rate. Menthol/beeswax particles with size in the range of 2–50 μm were produced. The effects of the process conditions, namely, the pre-expansion pressure, pre-expansion temperature, gas-saturated solution flow rate, and menthol composition, on the particle size, particle size distribution, and menthol encapsulation rate were investigated. Results indicated that in the range of studied conditions, increase of the pressure, decrease of the gas-saturated solution flow rate, and decrease of the menthol mass fraction can decrease the particle size and narrow particle size distribution of the produced menthol/beeswax microparticles. An N2-blowing method was proposed to measure the menthol release from the menthol/beeswax microparticles. Results showed that the microparticles have obvious protection of menthol from its volatilization loss.


2011 ◽  
Vol 80-81 ◽  
pp. 225-228
Author(s):  
Wen Yan Duan

Three graphite nanosheets were prepared by sonicating three expanded graphites that were formed by rapidly heating expandable graphite at 600, 800 and 1000 °C, respectively. The graphite nanosheets were characterized by scanning electron microscope. The anti-friction effects of the graphite nanosheets used as lubricating additives were investigated. The results show that the size of the graphite nanosheets decreases with increasing the temperature of expandable graphite. The graphite nanosheets have an obvious anti-friction effect, and the effect is related to the heating temperature.


2005 ◽  
Vol 475-479 ◽  
pp. 925-928
Author(s):  
Kenji Wakashima ◽  
T. Shimoyamada ◽  
H. Noma ◽  
Tomonari Inamura ◽  
Hideki Hosoda

In this paper, we describe our recent work on metal matrix composites (MMCs) with submicron-size TiB2 and Al2O3 particulates that are synthesized in situ from Al-rich Al-Ti-B and Al-TiO2- B powder reactants by reactive sintering. Reaction sequences examined in the two different reactant systems are summarized, and some experimental results on elevated-temperature properties, i.e. thermal expansion, temperature dependence of dynamic tensile modulus and creep behavior, are shown and discussed from micromechanics-based viewpoints.


2020 ◽  
Vol 57 (1) ◽  
pp. 197-201
Author(s):  
Virgil Geaman ◽  
Mihai Alin Pop ◽  
Irinel Radomir ◽  
Augustin Semenescu ◽  
Bogdan Florea ◽  
...  

The work focuses some experimental aspects concerning the weight gain, differential scanning calorimetric (DSC), dilatometer analysis (DIL) and thermo - gravimetric analysis (TG/DTA) for a composite material, based on cotton tissue and unsaturated polyester resin noted MCTDBN and immersed in salt water with 5% NaCl for 90 days. Following these analyzes are emphasized the thermal expansion, temperature glass transition and thermal decomposition. Before of thermal analysis, the treated specimens were dried in an oven at temperature of 30�C for several days. The paper presents also the effect of salt solution treatment and comparative analysis between untreated and treated composites.


2021 ◽  
Vol 29 (19) ◽  
pp. 30567
Author(s):  
Zhiyuan Wang ◽  
Yanxia Ye ◽  
Jialu Chang ◽  
Jingxuan Zhang ◽  
Yunlong Sun ◽  
...  

Cryogenics ◽  
1995 ◽  
Vol 35 (1) ◽  
pp. 69-70 ◽  
Author(s):  
B.-Z. Maytal

2014 ◽  
Vol 962-965 ◽  
pp. 1112-1117
Author(s):  
Gang Xu ◽  
Rui Feng Ma ◽  
Quan Bin Mou

Based on definition of porosity, permeability model of gas-bearing coal was build which took porosity gas pressure, gas adsorption expansion, temperature and crustal stress into account, and the factors affecting the permeability of gas-bearing coal has been analyzed theoretically. The results show that permeability decreased exponentially with crustal stress increasing, permeability decreased linearly with temperature increasing and permeability decreased first and then increased with gas pressure increasing; crustal stress had the strongest effect than gas pressure and temperature, decreasing crustal stress was the most effective way to increase permeability and to improve extraction; the results verified by experiments data show that the smaller error and the higher prediction accuracy can meet production practical requirement, which could provide some guidance to gas extraction.


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3673
Author(s):  
Guiming Xie ◽  
Zhiyang Wang ◽  
Yongzhong Bao

Vinylidene chloride copolymer microspheres were synthesized by in situ suspension copolymerization of vinylidene chloride (VDC), methyl methacrylate (MMA), and/or acrylonitrile (AN) in the presence of a paraffin blowing agent. The effects of shell polymer properties including compositions, glass transition temperature (Tg), crosslinking degree, blowing agent type, and encapsulation ratio (Er) on the expansion properties of copolymer microspheres were investigated. Moreover, the diffusion properties of blowing agent in copolymer microspheres were studied. The results show that VDC-MMA-AN copolymer microspheres exhibited excellent expansion properties, and the volume expansion ratio (Ev) and the apparent density were decreased over 40 times, but it was difficult to expand for the VDC-MMA copolymer microspheres. In addition, the moderately crosslinked inside of the polymer shell enhanced the Ev more than 30 and the stable expansion temperature range (Tr) was about 30 °C by adding 0.2–0.4 wt% of divinyl benzene. The Tg of the shell polymer must be higher than the boiling point of the blowing agent as a prerequisite; the lower the boiling point of the blowing agent, the higher the internal gas pressure driven microsphere expansion, and the wider the Tr. By increasing the Er of blowing agent improved the Ev of the microspheres. The diffusion of pentane blowing agent in VDC-MMA-AN copolymer microspheres were divided into Fick diffusion and non-Fick diffusion.


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