• Title/Summary/Keyword: SEM/EDX analysis

Search Result 306, Processing Time 0.027 seconds

Adsorption properties and metal growth aspects on the surface of activated carbon monolith electrochemically deposited with Ag

  • Oh, Won-Chun;Lim, Chang-Sung
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.14 no.2
    • /
    • pp.37-46
    • /
    • 2004
  • The electrochemical adsorption of the Ag ions from aqueous solution on pelletized activated carbon monolith was investigated over wide range of operation time. The adsorption capacities of pelletized activated carbon monolith are associated with their internal porosity and are related properties such as surface area, pore size distribution. The chemical industry generates wastewater that contains toxic matters like heavy metals in small concentrations so that their economic recovery is not feasible. But, the method using activated carbon monolith can be used to withdrawal of heavy metals in waste water. After the electrochemical treatment, the quantitative properties in Ag ion solutions are also examined by pH concentration and studied elemental analysis by ICP-Atomic Emission Spectrometer and Energy Disperse X-ray (EDX) spectra. It is consider that the pH is very important factor at the reason of water pollutant with increasing acidity in industrial field. The result of quantitative analysis using Inductively Coupled Plasma-Atomic Emission Spectrometer of metal after electrochemical reaction in Ag ions solution depending on time are shown that the amount of Ag ions deposited was decreased with growth of Ag particles on the carbon surfaces as increasing electrochemically treated time. And, surface morphologies are investigated by scanning electron microscopy (SEM) to explain the changes in adsorption properties.

A Study on Dielectric Properties of Flame-Retardant Silicone Rubber Due to Silica Amount Change (실리카 양 변화에 의한 난연성 실리콘 고무의 유전특성에 관한 연구)

  • Lee, Sung Ill
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.34 no.5
    • /
    • pp.364-370
    • /
    • 2021
  • In this study, the dielectric properties of flame retardant silicone rubber mixed with the amount of silica 50~65 phr were measured at frequencies ranging from 1 to 2.7 MHz and temperature ranges from 30℃ to 160℃. The permittivity decreased with higher frequencies and higher temperatures, and tanδ are thought to have decreased due to the increased heat oxidation of the methyl group bound to Si, which increased the hardness of silicone rubber. FT-IR analysis of specimen mixed with SiO2 of 50~65 phr showed oscillations of OH groups bound to SiO2 between wavenumber 3,600 and 3,300. As a result of analyzing surface components by Energy Dispersive X-ray (EDX) on all specimens mixed with SiO2 of 50 to 65 phr, all specimens contained Si, and the analysis by field emission scanning electron (FE-SEM) confirmed that about 1~5 ㎛ particles were distributed regularly on the surface of the specimens.

A Study on the Cut Off Characteristics and Graphite Analysis of Residual Current Protective Devices for Low Voltage (저압용 누전차단기의 차단특성 및 그라파이트 분석에 관한 연구)

  • 최충석;이경섭;정재희;박수홍;김병수;이덕출
    • Journal of the Korean Society of Safety
    • /
    • v.14 no.1
    • /
    • pp.49-54
    • /
    • 1999
  • In this paper. we studied cut off characteristics and fire hazard of residual current protective devices(RCD or ELB) for low voltage. The operative time of RCD with grounding resistance was analyzed by using RCD operating tester. The surface structure and composition of insulator were analyzed by using scanning electron microscope(SEM) and energy dispersive x-ray spectroscopy(EDX). The surface of phenol resin showed network structure and void. The spectra shown in EDX analysis are composed not only of the corresponding elements but also of several new spectra, as CK. OK$\alpha$. MgK, SiK. and CaK, which were absent in original material.

  • PDF

A Study on Soil Cementation and Calcite Precipitation with Clay as a Medium (점토를 매개체로 한 탄산칼슘 석출 및 흙의 고결에 관한 연구)

  • Park, Sung-Sik;Suh, Eun-Hee;Chae, Kyung-Hyeon;Jang, Sang Kyu;Kim, Jin-Ho
    • Journal of the Korean Geotechnical Society
    • /
    • v.31 no.12
    • /
    • pp.17-27
    • /
    • 2015
  • In this study, we tried to precipitate calcium carbonate with carbonate ions decomposed from urea by plant extract and calcium ions dissolved in water. The clay particles carry a net negative charge on their surfaces. Such clay mineral was additionally mixed as a medium to improve soil strength and durability with environmentally-friendly way. The $1^{st}$ solution (plant extracts and urea) and the $2^{nd}$ solution (calcium chloride and clay) were mixed together with clean Nakdong River sand. Then, this mixed soil was compacted into a small cylindrical specimen and then air cured for 7 days in laboratory. The molar concentration of urea and calcium chloride was tested for three different conditions, 1, 5, and 7 mol. Three different clay contents (0, 1, and 3% per total weight) were mixed with sand. For each specimen, a series of unconfined compression test, a durability test, SEM, EDX and XRD analyses were carried out to evaluate its cementation and structure. As the molar concentration of the solution and clay content increased, the unconfined compressive strength and durability increased. The results of SEM, EDX and XRD analyses showed that calcite was precipitated around clay mineral. The thermogravimetry analysis indicated that calcium carbonate precipitated about 1~2% per total weight of the sample.

Surface Characteristics and Biocompatibility of Titanium Coated with Dentin-derived Hydroxyapatite

  • Kim, Hae-Jin;Son, Mee-Kyung;Lee, Kyung-Ku;Lee, Bo-Ah;Kim, Young-Joon
    • International Journal of Oral Biology
    • /
    • v.37 no.1
    • /
    • pp.9-16
    • /
    • 2012
  • The aim of this study was to evaluate surface characteristics and biological properties of the dentin -derived hydroxyapatite (HA) coating on titanium substrate. Dentinderived HA was obtained from extracted human teeth using a calcination method at $850^{\circ}C$. The commercially pure titanium (cp-Ti, ASTM Grade II) was used as a metallic substrate and a radio frequency magnetron sputtering method was employed as a coating method. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were utilized to investigate the coating aspects and composition. Atomic forced microscopy (AFM) and a surface profiler were used to assess the surface morphology and roughness. Corrosion tests were performed in phosphate-buffered saline at a $36.5{\pm}1^{\circ}C$ in order to determine the corrosion behavior of the uncoated and coated specimens. The biocompatibility of dentin-derived HA coated specimens with fetal rat calvarial cells and human gingival fibroblasts was assessed by SEM and cell proliferation analysis. The results showed that the dentin-derived HA coatings appeared to cover thinly and homogeneously the surfaces without changing of the titanium substrate. The EDX analysis of this the coating surface indicated the presence of Ca and P elements. The mean surface roughness of cp-Ti and dentin-derived coating specimens was $0.27{\mu}m$ and, $1.7{\mu}m$, respectively. Corrosion tests indicated a stable passive film of the dentin-derived HA coating specimens. SEM observations of fetal rat calvarial cells and human fibroblast cells on coated surfaces showed that the cells proliferated and developed a network of dense interconnections. The cells on all specimens proliferated actively within the culture period, showing good cell viability. At day 1 and 3, dentin-derived coating specimens showed 89% and 93% cell viability, respectively, when normalized to cp-Ti specimens. These results suggest that dentin-derived HA coating using the RF magnetron sputtering method has good surface characteristics and biocompatibility.

The Cause Analysis on Fracture of Dropper Clamp in Catenary System (전차선로 드로퍼 클램프 파단 원인 분석)

  • Kim Jung-Nam;Kwon Sung-Tae;Kang Kae-Myung
    • Proceedings of the KSR Conference
    • /
    • 2004.06a
    • /
    • pp.909-914
    • /
    • 2004
  • This study investigate the cause analysis on fracture of dropper clamp in catenary system. Dropper clamp is using as a holder between messenger wire and contact wire in catenary system. To analyze the cause analysis on fracture of dropper clamp, we have conducted experiment such as tension withstand strength test, holding strength test of a new products, SEM and EDX of field fractured specimens.

  • PDF

The cause analysis of broken accident on messenger wire in catenary system (수도권 전철구간에서 발생한 조가선 절단원인 분석)

  • Jang Dong-Uk;Lee Ki-Won
    • Proceedings of the KSR Conference
    • /
    • 2003.10c
    • /
    • pp.552-557
    • /
    • 2003
  • The catenary system used in urban electrification railway have suffered mechanical and chemical stresses. These brought out severe messenger wire problems, these have caused accident. Especially, messenger wire is severely influenced by corrosion, vibration and tension. This paper investigate for the cause analysis of broken accident on messenger wire in catenary system. To analyze the cause analysis of accident, we have conducted experiment such as XRD, SEM, EDX and tensile test.

  • PDF

A STUDY FOR THE NATURE OF PIGMENTATION ADJACENT TO TITANIUM MINIPLATE OSTEOSYNTHESIS (티타늄 소강판 주위조직에 발생한 색소침착의 성질에 관한 연구)

  • Weon, Dong-Whan;Joo, Hyun-Ho;Lee, Sang-Hwy;Kim, Il-Hyun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.27 no.1
    • /
    • pp.25-31
    • /
    • 2001
  • The titanium miniplate osteosynthesis system has been used for fixation of bone fragments in the maxillofacial areas due to easy manipulation and even has been proposed for unnecessity of miniplate removal because of the biocompatibility and the corrosion resistance. But recently, there have been some suggestions for its removal, on the basis of findings that there have been pigmentations around the adjacent tissues during miniplate removal procedure and they are the depositions of metal particles. Purposes of this study are to ascertain the presence and nature of pigmentation observed within tissues adjacent to titanium miniplate, and to suggest possible causes of it. We could observe the black pigmentation during miniplate removal procedure for recent about 1.5 year. Pigmented tissues were stained with hematoxylin-eosin(H-E) for light microscophic(LM) examination to investigate the black pigmentations and the histomorphology around them. The scanning electron microscopy(SEM) with energy dispersive X-ray(EDX) analysis was used to examine the ultrastructural nature of pigmentations. Many metal particles with variable sizes and shapes were seen in the connective tissue by SEM and were identified as titanium by EDX.

  • PDF

Characteristics of Surface Modified Activated Carbons Prepared by Potassium Salt Sequentially After Hydrochloric Acid Treatment

  • Oh, Won-Chun;Park, Chong-Sung;Bae, Jang-Soon;Ko, Young-Shin
    • Carbon letters
    • /
    • v.7 no.1
    • /
    • pp.34-41
    • /
    • 2006
  • The objective of this paper is to compare the variation of surface properties by hydrochloric acid pre-treatment and of metallic potassium and their salts loading effect for activated carbon after surfaces transformation by acid. From the results of nitrogen adsorption, each isotherm shows a distinct knee band, which is closely related to the characteristic of microporous carbons with capillary condensation in micropores. In order to present the causes of the differences in surface properties and $S_{BET}$ after the samples were treated with hydrochloric acid, pore structure and surface morphology are investigated by adsorption analysis. X-ray diffraction (XRD) patterns indicate that activated carbons show better performance for metallic potassium and potassium salts by pre-treatment with hydrochloric acid. Scanning electron microscopy (SEM) pictures of potassium/activated carbon particles provide information about the homogeneous distribution of metal or metal complex on the surface. For the chemical composition microanalysis for potassium treatment of the activated carbon pre-treated with hydrochloric acid, samples were analyzed by energy disperse X-ray (EDX). Finally, the type and quality of oxygen groups are determined from the method proposed by Boehm. A positive influence of the acidic groups on the carbon surface by acid treatment is also demonstrated by an increase in the contents of potassium salts with increasing of acidic groups calculated from Boehm titration.

  • PDF

A Study on the Coating Method of Platinum based Catalyst for Odor Gas and VOCs Oxidation (악취가스 및 휘발성 유기 화합물 산화를 위한 백금계 촉매의 코팅 방법에 관한 연구)

  • Shin, Jung Hun;Jung, Min Gie;Hong, Sung Chang
    • Applied Chemistry for Engineering
    • /
    • v.32 no.5
    • /
    • pp.497-503
    • /
    • 2021
  • In this study, different methods to coat honeycomb and metal foam substrate with platinum/titania for removing odor gases and volatile organic compounds were investigated. Among them, the powder coating and the nano coating were compared. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) analysis was used to investigate the surface conditions and exposed platinum composition ratios on honeycomb and metal foam. Also, the catalytic oxidation performance of toluene, trimethylamine and isopropyl alcohol was compared according to the coating method.