• Elastomers and Composites
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• 제54권3호
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• pp.182-187
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• 2019

To improve the mechanical properties of glass-fiber-reinforced polypropylene (PP) composites through interfacial adhesion control between the PP matrix and glass fiber, the surface of the glass fiber was modified with PP-graft-maleic anhydride (MAPP). Surface modification of the glass fiber was carried out through the well-known hydrolysis-condensation reaction using 3-aminopropyltriethoxy silane, and then subsequently treated with MAPP to produce the desired MAPP-anchored glass fiber (MAPP-a-GF). The glass-fiber-reinforced PP composites were prepared by typical melt-mixing technique. The effect of chemical modification of the glass fiber surface on the mechanical properties of composites was investigated. The resulting mechanical and morphological properties showed improved interfacial adhesion between the MAPP-a-GF and PP matrix in the composites.

• 센서학회지
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• 제17권2호
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• pp.95-99
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• 2008

Various etching methods of optical fiber and formation of metal nano particles on the optical fiber have been proposed for fabrication of fiber optic localized surface plasmon resonance (FO LSPR) biosensors. Different types of etched optical fiber are possible by removing the cladding of optical fiber using HF (hydrofluoric acid) solution and BHF (buffered hydrofluoric acid) solution, which results in improved surface roughness when BHF solution is used. Localized surface plasmon can be formed and measured by formation of silver and gold nano particles on the etched optical fiber. The characteristics of the etched optical fiber and metal nano particles on the etched surface of the optical fiber play a key role in dictating the sensitivity of the LSPR sensors, so that the proposed results can be expected to be applied for related research on fiber optic based biosensors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.581-583
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• 1993

One of the principal problems encountered in the use of fiber reinforced composites is to establish an active fiber surface to achieve maximum adhesion between resin and fiber surface. In order to improve the interface bonding, the surface of glass fiber should be treated with silane coupling agent in ordinary composite manufacturing processes. However, the price of the coupling agent is very high and in the treating process voids are formed, which decreasees electrical and mechanical strength. We want to develope new process that will overcome the disadvantage of the coupling agent and achieve maximum adhesion at the interface between resin and fiber by active plasma treatment on the glass fiber surface. In this study, we investigate the improvement of contact angle on the glass plate surface as the first step in developing new GFRP.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.283-286
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• 2002

In fiber optic sensor, the error of the measurement is influenced by the surface roughness of the target and surroundings, especially the outside light. To reduce or modify this error, the sensitivity of the fiber optic sensor and the noise change by the surface roughness of the target should be known. The purpose of this paper is to observe the sensitivity of the fiber optic sensor and the noise according to the surface roughness of the target.

• Elastomers and Composites
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• 제57권4호
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• pp.175-180
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• 2022

To produce a co-poly-para-aramid fiber (AF, Technora^®)-reinforced neoprene rubber composite, dispersion of AF in a neoprene matrix is investigated. The AF is then surface-modified by mercerization and acetone, plasma, and silane treatments to improve dispersibility. Finally, an internal mixer process is used to disperse the surface-modified fibers in the neoprene rubber matrix.

• Advances in concrete construction
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• 제16권6호
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• pp.277-290
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• 2023

In order to study the mechanical properties of basalt fiber reinforced ultra-fine fly ash concrete (BFUFARC), the effects of ultra-fine fly ash (UFA) content, basalt fiber content, basalt fiber length and water reducing agent content on the compressive strength, splitting tensile strength and flexural strength of the composite material were studied through experimental and theoretical analysis. Also, a scanning electron microscope (SEM) was employed to analyze the mesoscopic structure in the fracture surface of composite material specimens at magnifications of 500 and 3500. Besides, the energy release rate (G_c) and surface free energy (γ_s) of crack tip cracking on BFUFARC in different basalt fiber content were studied from the perspective of fracture mechanics. Further, the cracking resistance, reinforcement, and toughening mechanisms of basalt fibers on concrete substrate were revealed by surface free energy of BFUFARC. The experimental results indicated that basalt fiber content is the main influence factor on the splitting tensile strength of BFUFARC. In case that fiber content increased from 0 to 0.3%, the concrete surface free energy at the tip of single-sided crack showed a trend of increased at first and then decreased. The surface free energy reached at maximum, about 3.59 × 10^-5 MN/m. During the process of increasing fiber content from 0 to 0.1%, G_C-2_γS showed a gradually decreasing trend. As a result, an appropriate amount of basalt fiber can play a preventing cracking role by increasing the concrete surface free energy, further effectively improve the concrete splitting tensile performance.

• 한국염색가공학회지
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• 제27권1호
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• pp.18-26
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• 2015

para-aramid fibers were treated by atmosphere air plasma to improve the interfacial adhesion. The wettability of plasma-treated aramid fiber was observed by means of dynamic contact angle surface free energy measurement. Surface roughness were investigated with the help of scanning electron microscopy and atomic force microscopy. The tensile test of aramid fiber roving was carried out to determine the effect of plasma surface treatments on the mechanical properties of the fibers. A pull-out force test was carried out to observe the interfacial adhesion effect with matrix material. It was found that surface modification and a chemical component ratio of the aramid fibers improved wettability and adhesion characterization. After oxygen plasma, it was indicated that modified the surface roughness of aramid fiber increased mechanical interlocking between the fiber surface and vinylester resin. Consequently the oxygen plasma treatment is able to improve fiber-matrix adhesion through excited functional group and etching effect on fiber surface.

• 센서학회지
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• 제18권3호
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• pp.226-233
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• 2009

In this study, the optical properties of localized surface plasmon resonance sensor using optical fiber was analyzed as the variation of a size and surface density of gold nano particles on the etched optical fiber surface. It is shown that a size and surface density of gold nano particles on optical fiber surface are controlled by $Na_3$ citrate quantity and pH of gold colloid solution. To measure the sensitivity, peak wavelength of absorbance spectrum was detected as the reflective index of the solution. The sensor sensitivity is linearly dependent on the size and surface densities of gold nano particles from the results of optical experiments.

• Carbon letters
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• 제11권2호
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• pp.131-136
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• 2010

Propellant waste was impregnated on the surface of activated carbon fiber and heat-treated at different temperature to introduce newly developed functional groups on the ACF surface. Functional groups of nitrogen and oxygen such as pyridine, pyridone, pyrrol, lacton and carboxyl were newly introduced on the surface of modified activated carbon fiber. The porosity, specific surface area, and morphology of those modified ACFs were changed as increasing the heat-treated temperature from 200 to $500^{\circ}C$. The optimum heat-treatment temperature was suggested to $500^{\circ}C$, because lower temperature given rise to the decrease of specific surface area and higher temperature resulted in the decrease of weight loss. Propellant waste can be used as an useful surface modifier to porous carbons.

• 동력기계공학회지
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• 제12권3호
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• pp.55-59
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• 2008

In this paper, we have investigated on collection efficiency of fine particle of glass fiber-filter bag according to the surface treatment. The solution consisted of polytetrafluoroethylene(teflon), graphite powder, silicon resin and water was used as a basic surface treatment agent. Tensile strength of glass filter-bag increased with up to 3hrs and then decreased with surface treatment time. Tensile strength and initial modulus of the glass fiber-filter bag treated by iodine after basic surface treatment for 3hrs were lower than those of basic surface treatment for 3hrs, however collection efficiency and fracture strain were higher than those of basic surface treatment for 3hrs. Glass fiber-filter bag with lower initial modulus and more strain will be extend the durable period and the one treated by iodine after basic surface treatment 3or 3hrs is expected high collection efficiency of fine particle. This method makes it possible to manufacture glass fiber-filter bag of the optimum condition.