무기질섬유 계면처리에 따른 무기섬유강화 시멘트복합체의 계면결착특성에 관한 연구

최응규(Choi Eung-Kyoo),김연희(Kim Yeon-Hee) 대한건축학회 2009 大韓建築學會論文集 : 構造系 Vol.25 No.3

The purpose of this study was to present surface adhesion characteristics of inorganic fiber-reinforced cement composite based on the results of experiment on the cement composite by the interfacial agent for the inorganic fiber PAM (Polyacrylamide). To improve surface adhesion between the inorganic fiber and cement in the inorganic fiber-reinforced cement composite, N-PAM (Nonion), C-PAM (Cation) and A-PAM (Anion), etc. were used as interfacial adhesives. Analysis of the physical properties of inorganic fiber-reinforced cement composite showed that C-PAM adhesive is an optimal interfacial treatment agent for the carbon fiber, whereas A-PAM adhesive is optimal for the epoxy coating carbon fiber. The excellent interfacial adhesion and physical properties of the cement composite were likewise revealed. Besides, the study of the tensily crushed cross section of the cement composite showed that the cement composite using interfacial treatment of the inorganic fiber manifests excellent refinement in the inner structure and interfacial adhesion, along with improved relevant physical properties. Results showed that the epoxy coating carbon fiber has better interfacial adhesion than the carbon fiber. When interfacial adhesion is reinforced by the interfacial adhesive for inorganic fiber, C-PAM was found to be suitable for the carbon fiber, whereas A-PAM adhesive was suitable for the epoxy coating carbon fiber. Analysis of the physical properties of inorganic fiber-reinforced cement composite showed that the epoxy coating carbon fiber has stronger interfacial adhesion to the cement interfacial structure, and better physical characteristics and mechanical properties than the carbon fiber.

무기섬유보강 시멘트복합체에서 계면결착제가 무기섬유계면에 미치는 영향

최응규(Choi Eung-kyoo),고성석(Go Seong-seok),김선국(Kim sun-kuk) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.4

The objective of the study is to examine the characteristic correlations between reinforcing inorganic fiber and interfacial adhesion agent since the interfacial adhesion strength between reinforcing inorganic fiber and matrices is believed to be an essential element influencing the physical properties in inorganic fiber reinforced cement composite using slurry method. The integrity of interfacial adhesion between reinforcing fiber and cement not only affects the quality of fiber reinforced cement composite but also influences to a large degree the physical properties of the cement composite when producing inorganic fiber reinforced cement composite using slurry method. IIaving analyzed the physical properties i.e., water content, tensile strength, flexural strength and flexural toughness of inorganic fiber reinforced cement composite specimens, C-PAM(cation polyacrylamide) was determined to be an optimum interfacial adhesion agent. The study has also demonstrated that interfacial adhesion strength varies large]y on the content and type of the reinforcing fiber. Judging from magnified view of the tensile shear cross-section using VMS (video microscope system), interfacial adhesion strength between reinforcing fiber and matrices is affected by the type of interfacial adhesion agent. According to the result of the experiments, C-PAM was determined to be an ideal interfacial adhesion agent when using carbon fiber in producing inorganic fiber reinforced cement composite with the optimum content of carbon fiber being estabJished.

무기충전재 함량에 따른 PVA섬유강화 시멘트복합체의 계면결착특성 및 물성고찰

최응규(Choi Eung-Kyoo) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.8

The aim of the study is to suggest an optimal inorganic filler and its contents applicable to PVA fiber reinforced cement matrix by means of quantifying the degree of interfacial adhesion between a selected range of inorganic filler materials and PVA fibers followed by analyzing physical and mechanical properties of PVA fiber reinforced cement composite in relation to the contents of inorganic filler. Based on the result of analysis on interfacial adhesion between inorganic filler and PVA fiber materials, kaolin, fly ash andmica have proved to be excellent filler materials for cement matriceshaving superior adhesion performance with PVA fibers.Compactness of cement matrix is influenced by chemical components and their content of the respective filler material being used.In addition physical properties are heavily affected by type of filler materials and its configuration. Observing the failure plane ofPVA fiber-reinforced cement composite mixed with one of the optimal filler materials, mica, the specimens have exhibited highdegree of compactness with little PVA fibers pulled out within the cement matrix. The key elements in producing fiber reinforced cement matrix using a range of filler materials are: (1) Selection of filler material chemically compatible with reinforcing fibers (2) Maintaining maximum adhesion between reinforcing fiber and filler material (3) Use of optimal content of filler materials. The experimental study has determined that when PVA fiber is used in cement matrix, mica proved to be the most suitable filler material and the range of content is from 20% to 25%.

유기 및 무기 섬유로 보강한 포트랜드 시멘트의 물성 연구

장복기,김윤주,Chang Pok-Kie,Kim Yun Ju 한국세라믹학회 2004 한국세라믹학회지 Vol.41 No.9

본 연구에서는 무기(강, 아스베스트와 카본) 및 유기(폴리아크릴과 폴리아마이드) 섬유가 포트랜드 시멘트의 물성 보강에 미치는 영향을 조사하였다. 각 시편의 하중-변형 관계도로부터 굽힘강도, 탄성계수, 파괴에너지 및 파괴인성 값을 구하여 서로 비교하였다. 그리고 따로 충격에너지 실험도 수행하였으며 파괴에너지와 비교하였다. 휨강도 개선에는 무기(아스베스트) 섬유보강이 가장 효과적이었으며, 충격에너지의 보강섬유로는 유기(폴리아크릴) 섬유가 가장 좋았다. 한편 강 섬유는 휨 강도와 충격에너지 양자를 동시에 보강하는 데에 가장 적합했다. 또한 강 섬유는 모든 섬유 중에서 가장 높은 파괴에너지와 파괴인성 값을 나타내었다. In this study, inorganic (steel, asbestos and carbon) and organic (polyacryl and polyamide) fibers were used to investigate their reinforcing effects of the physical properties of Portland cement. From the load-displacement curve of each reinforced specimen, fracture strength, Young's module, fracture energy and fracture toughness were computed and compared with each other. In addition, the experiment of their impact toughness was carried out and compared with the fracture energy. For the improvement of fracture strength the inorganic (asbestos) fiber reinforcement was most effective, while the best reinforcing effect of impact toughness was achieved by organic (polyacryl) fiber. And steel fiber proved to be most adequate for improvement of both fracture strength and impact toughness. Steel fiber also showed the highest fracture energy and fracture toughness among all of the fibers.

유기질섬유 계면처리에 따른 유기섬유강화 시멘트복합체의 계면구조특성 및 물성고찰

최응규(Choi Eung-Kyoo) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.8

The aim of the study is to analyze physical and mechanical properties of cement composite specimens by way of adding varying contents of a selected range of Polyacrylamides(PAMs) as interfacial coupling agent for organic fibers. In line with the aim of the study, mode of failure has also been carefully examined. Based on the experiment, the study attempts to suggest a characteristic of interfacial structure matrix and physical properties of organic fiber-reinforced cement composite. In the experiment, N-PAM(Nonion), C-PAM(Cation) and A-PAM(Anion) were used as interfacial coupling agent for organic fibers such as PVA and acrylics. The experiment has demonstrated A-PAM for PVA fibers and C-PAM for acrylic fibers to be an optimum interfacial coupling agent for the respective organic fibers in terms of both interfacial adhesion and physical properties. When an inappropriate interfacial treatment agent was used, a number of organic fibers were found to have been pulled out and the matrices were found to be loose. It is evident from the experiment that there is an optimal PAM as interface treatment agent for respective organic fibers, producing high degree of compactness of the matrix as well as excellent physical properties including interfacial adhesion. The experiment has demonstrated that when PVA fibers are treated with A-PAM and acrylic fibers with C-PAM, PVA fibers proved to be superior to acrylic fibers in terms of adhesion to cement matrix as well as in terms of physical and mechanical properties.

석면대체 아크릴섬유강화 시멘트복합체에서 각 구성소재의 최적조건 및 물성연구

최응규(Choi Eung-kyoo) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.7

The objective of the study is to analyze the optimum condition and properties of the components necessary for producing acrylic fiber-reinforced cement composite using acrylic fiber, usage of which is now common in most developed countries, as a substitute for asbestos. When acrylic fiber is used as reinforcing fiber in a cement composite, C-PAM(Cation Polyacrylamide) proved to be an optimum interfacial coupling agent in terms of adhesion between acrylic fiber and cement. Excellent degree of internal compactness of the cement composite can be achieved in respect of water content and water absorption by adding adequate amount of acrylic fiber and C-PAM. In respect of tensile and flexural properties, the content of acrylic fiber has significant effect not only on the interfacial adhesion and compactness of the matrices also on the properties of the cement composite. Having examined the tensile failure planes of acrylic fiber-reinforced cement composite, the content of reinforcing fiber determines the mode of failure either pullout or shear of the fibers in the matrix. Optimization of the fiber content is therefore crucially important in the mixture of cement composites. The study has demonstrated that acrylic fiber-reinforced cement composite with excellent interfacial adhesion can be achieved by combining the three key components - acrylic fiber, talc and recycled sulfite pulp, mixed with C-PAM as interfacial coupling agent - with their optimum content being 2.0∼2.5%, 25% and 3.0%, respectively.

Fabrication and Properties of Glass Fiber-Reinforced Composites Using Polyimide Prepregs with Inorganic Nanofillers

임다정,박준철,장시훈,최준,박노형 한국섬유공학회 2021 Fibers and polymers Vol.22 No.3

Numerous studies have addressed the utilization of polyimide (PI) and silica for improving the properties of hybridcomposites. However, the applicability of polyhedral oligomeric silsesquioxanes (POSSs) has not been elucidated. Herein,inorganic nanoparticles containing poly(amic acid)s (PAAs) were synthesized; further, glass fibers (GFs) were impregnatedwith PAA solutions to obtain PAA prepregs. PI-based fiber-reinforced composites were manufactured with the prepregs byusing the hand lay-up technique. The morphology and the thermal, mechanical, and dielectric properties of the compositeswith inorganic nanoparticles were analyzed to investigate the effects of inorganic additives. The addition of inorganicparticles were observed to primarily improve the properties of the PI-based fiber-reinforced composites as compared to thoseof the neat PI composites. While this improvement was limited in the case of the addition of POSSs owing to the aggregationand a poor interaction with the PI matrix, silica-containing composites exhibited superior thermal, mechanical, andparticularly dielectric properties as compared to those of the composites containing POSSs; this was because of the increasein the dispersion of silica nanoparticles that was caused by a silane coupling agent (SCA). The results obtained in this studycan be utilized for applications pertaining to the design of PI composites with high mechanical strengths, enhanced thermalstabilities, and low dielectric constants.

전기방사법에 의한 $SiO_2$-$TiO_2$계 복합무기섬유의 제조 및 광촉매 활성 평가

현동호,김상범,이승구,정원양,김진호,이성욱,Hyun, Dong-Ho,Kim, Sang-Beom,Lee, Seung-Goo,Chung, Won-Yang,Kim, Jin-Ho,Lee, Sung-Wook 한국섬유공학회 2009 한국섬유공학회지 Vol.46 No.5

A series of $SiO_2$-$TiO_2$ composite sols have been prepared by the hydrolysis of tetraethyl orthosilicate (TEOS) and titanium (IV) isopropoxide dissolved in isopropanol which was controlled by HCl addition. The maximum amount of $TiO_2$ for suitable fiber formation was about 50 mol% in $SiO_2$-$TiO_2$ composite inorganic fibers. The SEM, TEM, and FT-IR results showed that the surface morphology and crystalline phase of the electro spun composite micro/nanoscale $SiO_2$-$TiO_2$ fibers were strongly affected by the content of $TiO_2$ and calcination temperature. The SEM and TEM images reveal that the fibers had diameters varying from hundreds of nanometer to 2 micrometer. The photocatalytic activity of composite inorganic fibers was evaluated by decomposition of methylene blue, acetaldehyde, and formaldehyde in waste water which are recognized as volatile organic compounds (VOCs).

국내 공기 중 섬유상 물질의 존재실태와 석면의 분석방법에 대한 고찰

황진연 ( Jinyeon Hwang ),오지호 ( Jiho Oh ),이효민 ( Hyomin Lee ),이진현 ( Jinhyun Lee ),손병서 ( Byeongseo Son ) 한국광물학회 2015 광물과 암석 (J.Miner.Soc.Korea) Vol.28 No.2

부산과 울산의 중심지역에 대해 공기 중의 분진시료를 채취하여, 위상차현미경, 위상차분산현미경, 주사전자현미경 등으로 석면을 분석한 결과, 석면은 검출한계 이하로서 확인되지 않았다. 공기중의 분진시료에는 섬유상물질이 다수 포함되었으나, 이들은 대부분 유기질 섬유인 것으로 나타났다. 무기질 섬유물질로는 암면, 세라믹섬유, 석고 등이 소량 포함되었으며, 비섬유상인 석영, 방해석, 장석등의 광물도 가끔 관찰되었다. 국내의 공기 중 분진의 석면분석은 주로 위상차현미경으로 관찰하는 것으로 규정되어 있으나, 이것만으로는 석면의 식별이 불가능한 것으로 나타났다. 따라서 일본 JIS법과 같이 저온회화 처리 장치에 의한 유기물질 제거 후에 분산염색법으로 석면을 식별하고 계수하는것이 효율적인 것으로 사료된다. Dust samples collected from air in metropolitan areas of Busan and Ulsan were analyzed by phase contrast microscopy, phase contrast dispersion microscopy and SEM. Asbestos concentration in dust samples was lower than detection limit. Many fibrous materials were observed in dust samples, but most of them were organic fibers. Inorganic fibers such as rock fiber, ceramic fiber and gypsum were contained in the samples and non-fibrous minerals such as quartz, calcite and feldspar were also occasionally observed. Domestic law requires that asbestos in air dust is mainly analyzed by phase contrast microscopy. From this study, however, precise analysis of asbestos was almost impossible by this method only. As indicated in JIS method of Japan, therefore, count and identification of asbestos were more efficient by dispersion staining method after removing organic materials in samples by low temperature incinerator.

삼중수소 검출용 광섬유 방사선 센서의 제작 및 특성분석

장경원,조동현,유욱재,이봉수,문주현,박병기,조영호,김신,Jang, Kyoung-Won,Cho, Dong-Hyun,Yoo, Wook-Jae,Lee, Bong-Soo,Moon, Joo-Hyun,Park, Byung-Gi,Cho, Young-Ho,Kim, Sin 한국광학회 2009 한국광학회지 Vol.20 No.4

본 연구에서는 무기섬광체와 광섬유를 이용하여 삼중수소 검출용 광섬유 방사선 센서를 제작하였다. 무기섬광체 선택을 위해 $Gd_2O_2S$ : Tb, $Y_3Al_5O_{12}$ : Ce, CsI : Tl을 이용하여 센서팁을 제작한 후, 금속 수소화물 형태의 삼중수소를 이용하여 섬광효율이 가장 좋은 섬광체를 선별하였다. 또한 선정된 섬광체를 사용하여 제작한 센서를 이용하여 삼중수소 선원으로부터 거리에 따른 섬광량을 계측하였고 선원의 방사능 세기에 따른 섬광량을 측정하여 표면 방사능 모니터의 결과와 비교 분석하였다. In this study, we have fabricated a fiber-optic radiation sensor for detection of tritium using inorganic scintillators and optical fibers. We have tested various kinds of inorganic scintillators such as $Gd_2O_2S$ : Tb, $Y_3Al_5O_{12}$ : Ce, and CsI : Tl to select the most effective sensor tip. In addition, we have measured the scintillating lights using a photomultiplier tube as a function of distance between sensor tips to the source with the different activities of hydride tritium. The final results are compared with those which are obtained using a surface activity monitor.