Tunable electrical properties of polystyrene/gold core-shell structure by in situ metallization of cationic gold complex on selective ion-exchange sites

2009 ◽  
Vol 24 (1) ◽  
pp. 253-259 ◽  
Author(s):  
Jun-Ho Lee ◽  
Hyoukryeol Choi ◽  
Jae-Do Nam

Gold-coated polystyrene (PS) beads were fabricated by an in situ metallization route involving a cationic-gold complex with a controlled amount of sulfonic acid groups formed on the PS bead surface. The interaction ratio of SO3− to [Au(phen)Cl2]+ may be estimated to be 2.4, which means that 2.4 sulfonated groups will interact with one gold cationic ligand based on geometric considerations. A modeling methodology was developed to predict the mechanical deformation, conductivity, and contact surface area of a spherical bead under compression.

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 456
Author(s):  
Keita Yasumoro ◽  
Yushi Fujita ◽  
Hideki Arimatsu ◽  
Takuya Fujima

Polyethylene dioxythiophene and polyethylene sulfonic acid (PEDOT/PSS) composite is gathering attention as an organic transparent conductive film material. However, it requires a core-shell structure in which conductive PEDOT is covered with insulating PSS. Providing film formability and a carrier to PEDOT, the PSS shell hinders carrier conduction as an insulating barrier. In this study, we realized that creating a macro-separated PEDOT/PSS composite by using a polyelectrolyte brush substrate and in-situ PEDOT polymerization without the PSS barrier increases durability and conductivity in comparison with commercially available PEDOT/PSS film, achieving a conductivity of 5000–6000 S/cm.


Author(s):  
E. S. Boatman ◽  
G. E. Kenny

Information concerning the morphology and replication of organism of the family Mycoplasmataceae remains, despite over 70 years of study, highly controversial. Due to their small size observations by light microscopy have not been rewarding. Furthermore, not only are these organisms extremely pleomorphic but their morphology also changes according to growth phase. This study deals with the morphological aspects of M. pneumoniae strain 3546 in relation to growth, interaction with HeLa cells and possible mechanisms of replication.The organisms were grown aerobically at 37°C in a soy peptone yeast dialysate medium supplemented with 12% gamma-globulin free horse serum. The medium was buffered at pH 7.3 with TES [N-tris (hyroxymethyl) methyl-2-aminoethane sulfonic acid] at 10mM concentration. The inoculum, an actively growing culture, was filtered through a 0.5 μm polycarbonate “nuclepore” filter to prevent transfer of all but the smallest aggregates. Growth was assessed at specific periods by colony counts and 800 ml samples of organisms were fixed in situ with 2.5% glutaraldehyde for 3 hrs. at 4°C. Washed cells for sectioning were post-fixed in 0.8% OSO4 in veronal-acetate buffer pH 6.1 for 1 hr. at 21°C. HeLa cells were infected with a filtered inoculum of M. pneumoniae and incubated for 9 days in Leighton tubes with coverslips. The cells were then removed and processed for electron microscopy.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1201
Author(s):  
Xinghua Ji ◽  
Cheng Zhang ◽  
Shufeng Li

SiCp reinforced aluminium matrix composites (AMCs), which are widely used in the aerospace, automotive, and electronic packaging fields along with others, are usually prepared by ex situ techniques. However, interfacial contamination and poor wettability of the ex situ techniques make further improvement in their comprehensive performance difficult. In this paper, SiCp reinforced AMCs with theoretical volume fractions of 15, 20, and 30% are prepared by powder metallurgy and in situ reaction via an Al-Si-C system. Moreover, a combined method of external addition and an in situ method is used to investigate the synergistic effect of ex situ and in situ SiCp on AMCs. SiC particles can be formed by an indirect reaction: 4Al + 3C → Al4C3 and Al4C3 + 3Si → 3SiC + 4Al. This reaction is mainly through the diffusion of Si, in which Si diffuses around Al4C3 and then reacts with Al4C3 to form SiCp. The in situ SiC particles have a smooth boundary, and the particle size is approximately 1–3 μm. A core-shell structure having good bonding with an aluminium matrix was generated, which consists of an ex situ SiC core and an in situ SiC shell with a thickness of 1–5 μm. The yield strength and ultimate tensile strength of in situ SiCp reinforced AMCs can be significantly increased with a constant ductility by adding 5% ex situ SiCp for Al-28Si-7C. The graphite particle size has a significant effect on the properties of the alloy. A criterion to determine whether Al4C3 is a complete reaction is achieved, and the forming mechanism of the core-shell structure is analysed.


2012 ◽  
Vol 77 (7) ◽  
pp. 3640-3645 ◽  
Author(s):  
Mohammad A. Zolfigol ◽  
Ardeshir Khazaei ◽  
Ahmad R. Moosavi-Zare ◽  
Abdolkarim Zare ◽  
Hendrik G. Kruger ◽  
...  

2009 ◽  
Vol 147 (2-3) ◽  
pp. 302-306 ◽  
Author(s):  
D.S. Pito ◽  
I.M. Fonseca ◽  
A.M. Ramos ◽  
J. Vital ◽  
J.E. Castanheiro

2015 ◽  
Vol 127 (17) ◽  
pp. 5231-5235 ◽  
Author(s):  
Won Ju Phang ◽  
Hyuna Jo ◽  
Woo Ram Lee ◽  
Jeong Hwa Song ◽  
Kicheon Yoo ◽  
...  

2019 ◽  
Vol 7 (34) ◽  
pp. 19820-19830 ◽  
Author(s):  
Yuqian Sui ◽  
Yexin Du ◽  
Huayuan Hu ◽  
Jieshu Qian ◽  
Xuan Zhang

Generating acid–base interactions between sulfonic acid groups in a proton exchange membrane (PEM) and the incorporation of basic groups are effective approaches to improving the physicochemical properties of a membrane.


2008 ◽  
Vol 44 (2) ◽  
pp. 475-482 ◽  
Author(s):  
Yi Zheng ◽  
Li Pan ◽  
Yan-Guo Li ◽  
Yue-Sheng Li

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Qunying Wu ◽  
Guyu Xiao ◽  
Deyue Yan

Abstract2-Sulfonate p-terephthalic acid (sTA) was synthesized, and sulfonated polybenzimidazoles (sPBI) were prepared by direct polycondensation of 3,3’- diaminobenzidine (DAB) and sTA with 4,4’-oxybis(benzoic acid) (OBBA) or 2,2’- bis(4-carboxylphenyl)-hexafluoropropane (BCHFP). Thus the ether groups and hexafluoroisopropylidene units were incorporated into the backbone of the sPBI in order to improve the flexibility and solubility. The sPBI based on OBBA showed poor solubility, while the sPBI containing hexafluoroisopropylidene units were soluble in common solvents. sPBI-20 ~ sPBI-60 could form tough and transparent membranes by solution casting. sPBI indicated high thermal stability, the 5% weight loss temperature (T5%) which was higher than 520°C, decreased with the increase of degree of sulfonation. sPBI-20 ~ sPBI-60 showed no glass transition at temperatures lower than 380°C. In addition, sPBI showed low water uptake, low swelling ratio as well as excellent resistance to oxidation. But sPBI exhibited low proton conductivity because of the strong acid-base interactions between basic benzimidazole and sulfonic acid groups.


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