scholarly journals Effect of dispersant viscosity for self-assembly process of barium titanate aggregates in material texture of polyvinylidene fluoride composites —evaluation of multifractal dimension (Dq [q = 0, 1, 2]) and dielectric properties—

2022 ◽  
Vol 130 (1) ◽  
pp. 21-28
Author(s):  
Mariko TAKEDA ◽  
Haruna YAMAZAKI ◽  
Yoshihiro SATO ◽  
Makoto TANIMURA ◽  
Yasuhide INOUE ◽  
...  
2021 ◽  
pp. 002199832110573
Author(s):  
Fumio Munakata ◽  
Kazuya Ookubo ◽  
Mariko Takeda ◽  
Yoshihiro Sato ◽  
Yuka Mizukami ◽  
...  

In the self-assembly process of β-Si3N4 (SN)/316L stainless-steel (SUS316L) composite materials tailored via sintering of powder mixtures, the formation of a SN agglomerate resulting from condensation–dispersion reactions during the stirring of SN/SUS316L was found to play an important role in improving the thermal conductivity. Moreover, the obtained SN secondary particle groups connected to form a network through diffusion-limited aggregation. In particular, it was shown that the sample prepared at the milling speed of 150 r/min has a similar particle group area (about 1.38 μm2) to that at 120 r/min, but a higher κ (increased from 9.5 W m−1 K−1 to 11.5 W m−1 K−1). To quantitatively evaluate the microstructural morphology of the texture of the self-assembled composite material, global parameters τ( q) and D q and local parameters α( q) and f( α) were determined via multifractal analysis. These characteristics of the anisotropy, dispersion, and cohesiveness of the particle network in the material texture could be analyzed together with the capacity dimension D0, information dimension D1 (configuration entropy), correlation dimension D2, and α( q) (related to internal energy). The results suggest that α( q) reflects the differences in the cohesion of the additive particle agglomeration that constitutes the self-assembly process under the solid-state reaction.


2021 ◽  
pp. 131567
Author(s):  
Fumio Munakata ◽  
Haruna Yamazaki ◽  
Mariko Takeda ◽  
Yuka Takagi ◽  
Hajime Nagata ◽  
...  

2016 ◽  
Vol 848 ◽  
pp. 369-373
Author(s):  
Zi Dong Zhang ◽  
Xiu Jie Ji ◽  
Chen Qin ◽  
Hui Min Wang ◽  
Shu Hui Chen ◽  
...  

In this paper, C/SiO2 bulk composite was prepared via SiO2 microspheres’ self-assembly process combined with heat treatment. SEM and impedance analyzer was used to investigate the microstructure and high-frequency dielectric properties of the composites. The results show that SiO2 microspheres constituted the composite matrix, whose porosity was slightly higher than the densest hexagonal stacking. Sheet carbon distributed in pores formed by SiO2 microspheres. The real and imaginary parts of the dielectric constant of the composite material increased with the content of carbon, but decreased with the frequency. The permittivity of C/SiO2 composite could be adjusted by control the concentration of PVA solution.


2018 ◽  
Vol 221 ◽  
pp. 147-149 ◽  
Author(s):  
Fumio Munakata ◽  
Kentaro Yoshino ◽  
Kazuhiro Nemoto ◽  
Satoko Abe ◽  
Akira Ito

Author(s):  
Krishna Sailaja A ◽  
Amareshwar P

In order to see the functionality and toxicity of nanoparticles in various food and drug applications, it is important to establish procedures to prepare nanoparticles of a controlled size. Desolvation is a thermodynamically driven self-assembly process for polymeric materials. In this study, we prepared BSA nanoparticles using the desolvation technique using acetone as desolvating agent. Acetone was added intermittently into 1% BSA solution at different pH under stirring at 700 rpm. Amount of acetone added, intermittent timeline of acetone addition, and pH of solution were considered as process parameters to be optimized. The effect of the process parameters on size of the nanoparticles was studied. The results indicated that the size control of BSA nanoparticles was achieved by adding acetone intermittently. The standard deviation of average size of BSA nanoparticles at each preparation condition was minimized by adding acetone intermittently. The intermittent addition in polymeric aqueous solution can be useful for size control for food or drug applications.  


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