• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
• /
• pp.23-24
• /
• 2015

As this study is an experiment for solving problem on the carbonation acceleration of high volume admixture concrete, the capillary pore getting filled up by saponification as cooking oil gets absorbed to the concrete surface in case of applying a cooking oil based coating agent to the concrete has been verified in the previous studies. Accordingly, this study has performed a comparative experiment on the cooking oil and the anticorrosive coating agent sold on the market while the result followed by this experiment has shown the fact of indicating similar carbonation penetration depth and porosity.

• 한국응용과학기술학회지
• /
• 제30권4호
• /
• pp.672-678
• /
• 2013

Although the basalt fiber has superior fire-resistance and chemical resistance, it has many disadvantages in its applications. Generally, the tensile and loop strengths of basalt fiber were decreased with generated frictional heat during industial appplications. To solve this problem, polytetrafluoroethylene (PTFE) coating system was introduced and a sutable coating condition was evaluated. The basalt fiber was pre-treated with triethoxytrifluoropropylsilane (TMTFPS) at various pHs and then coated with PTFE dispersions with penetrating agent sodium bis(2-ethylhexyl)sulfo succinate (DOS-Na) to increase the tensile and loop strengths as well as to reduce the fibril during working. A universial testing machine (Instron Model 3366) was used to measure tensile and loop strengths. When the PTFE dispersion with 0.25 wt% of DOS-Na was coated on the surface of basalt fiber after pre-treating with 5 wt% of PTFE, the highest tensile and loop strengths were reached to 3.5 gf/D and 2.4 gf/D, respectively.

• 한국재료학회지
• /
• 제13권9호
• /
• pp.555-560
• /
• 2003

Ag-coated Cu particles were prepared by dropping method of coating agent and were evaluated by scanning electron microscope and color difference meter. The shape of Cu particles having obvious crystal plan and edge was changed spherically according to the increase of Ag coating amount. When the Ag coating amount was 50 wt% to Cu particles, the whiteness of Ag-coated Cu particles was almost similar to that of pure Ag particles. Adding $NH_4$OH in reductant solution could increase effectively the whiteness of the Ag-coated particles. The Ag-coated particles having the highest whiteness was obtained when the content of hydrazine in reductant solution was 0.48 M.

• 열처리공학회지
• /
• 제19권4호
• /
• pp.200-207
• /
• 2006

In addition to the basic properties of the base and top coating agents, corrosion resistance of non-chrome magni 565 coating and characteristics of coating film when coated to steel substrate were studied. The system had a good wettability at room temperature. Moreover, both the contact angle and surface tension were affected little by the viscosity of coating agent and surface roughness of the steel substrate. And the samples coated with optimal conditions showed a great corrosion resistance in salt spray test with 1500 hours or longer of initial appearance time of rust. The coating film was composed of overlapping layer of zinc and aluminium flakes, and the thickness of base coat increased with an increase of base coat viscosity. Based on the C-F peaks of 1,1-Difluoroethaen homo-polymer, it was thought that the base coat was an inorganic polymer bond layer. Meanwhile, the top coat showed C-F peaks of polytetrafluoroethylene with C-H peaks of phenol in FT-IR analysis. From the lower weight loss of base coat in TG analysis, it was thought that cross linking density of base coat was larger than that of top coat. It was thought that the small exothermic reactions observed in DSC curves were due to the thermosetting resins contained in the coating agents. Compared to the non-coated specimen, the coated sample showed more higher polarization resistance and corrosion potential with lower corrosion current density.

• 한국환경보건학회지
• /
• 제40권6호
• /
• pp.484-491
• /
• 2014

Objectives: A radon emission reducing agent was prepared using charcoal and zeolite, and the amount was measured after coating construction materials with the agent. The availability of the radon emission reducing agent was evaluated. Methods: Construction materials (red brick, cement brick, and gypsum board) coated with reducing agent were placed in a chamber to measure radon emissions. The construction materials were coated one through three times. The spread volume for brick and gypsum board was 50 mL and 75 mL per application, respectively. The amount of radon emitted was measured by RAD-7 after 48 hours. Results: The reduction ratio increased with the number of coatings, and the reduction ratios for red brick, cement brick, and gypsum board were 63.3, 73.6, and 58%, respectively, in the case of three coatings of RA-1. The reduction ratios for red brick, cement brick, and gypsum board were 42.8, 58.1, and 26.2%, respectively in the case of three coatings with RA-2. RA-1 was slightly better than RA-2 in radon emission reduction. Conclusions: Radon emissions from construction materials decreased according to the concentration of reducing agent coating, and it was more effective than existing methods.

• Elastomers and Composites
• /
• 제50권2호
• /
• pp.98-102
• /
• 2015

A series of polyurethane-acrylate hybrids were synthesized by 2-step emulsion polymerization of a variety of acrylate monomers such as 2-hydroxy ethyl methacrylate (HEMA), methyl methacrylate (MMA). Experiment was performed to improve stability and emulsibility of surface treatment agent, and it was found that the polyurethane-acrylate hybrids having an optimum composition (MMA : 20%, LA(EO)3-S : 3% and TDA-7 : 5%) was shown to be quite surface active in the solid contents. These results suggests that the optimal polyurethane-acrylate hybrids in this study have high potential as top coating agent, which may have high gloss and excellent properties.

• 한국대기환경학회지
• /
• 제29권2호
• /
• pp.125-134
• /
• 2013

Various antimicrobial technologies have been developed to inactivate bioaerosols in indoor environments. In this study, air filter media were treated with a natural antibacterial agent of Sophora flavescens in order to inactivate the bacteria collected on the air filter. Three treatment methods were applied to manufacture the test antibacterial air filter media: electrospray, nebulization and dip-coating methods. In case of electrospray and nebulization processes, the size distribution of aerosolized natural antibacterial agent was measured using a scanning mobility particle sizer. Staphylococcus epidermidis bacteria were aerosolized to test inactivation of the filter media treated with a natural antibacterial agent. The pressure drop and the antibacterial efficiency of the filter media increased with increasing the mass loading of natural antibacterial agent in each treatment method. The antibacterial efficiency per loaded antibacterial agent mass by the electrospray method was the highest and the filter treated by the dip-coating method was the lowest among three treatment methods.

• 접착 및 계면
• /
• 제10권4호
• /
• pp.182-190
• /
• 2009

본 연구에서는 아스팔트 혼합물의 수분 손상을 감소시키기 위한 박리방지제 효과에 대하여 고찰하였다. 아스팔트 박리방지제는 tetraethylene pentamine (TEPA), Triethylenetetramine (TETA), 그리고 bis(hexamethylene)-triamine (BHMT) 각각과 포름알데히드의 축합반응에 의하여 합성하였다. 또한 스테아르산 또는 팔미트산과 금속 수산화물과의 반응을 통하여 금속계 박리방지제를 합성하였다. 박리방지제가 첨가된 아스팔트 혼합물의 기계적 특성은 마샬안정도, 수침잔류안정도 및 피막률에 대하여 분석하였다. 본 연구에서 합성된 박리방지제는 아스팔트 혼합물의 수분손상을 감소시켰다. 특히 BHMT계 및 C/S (Calcium stearate hydroxide) 박리방지제가 가장 높은 수침잔류 안정도 및 피막률을 보였다. 왜냐하면 각각 아민농도의 증가, 그리고 금속계면활성제의 효과적 역할로 인하여 BHMT 박리방지제와 C/S 박리방지제는 아스팔트와 골재 사이의 접착력을 향상시켜 주었기 때문이다.

• 월간포장계
• /
• 통권363호
• /
• pp.50-52
• /
• 2023

• 한국세라믹학회지
• /
• 제54권6호
• /
• pp.492-498
• /
• 2017

A thermal barrier coating (TBC) with self-healing property for cracks was proposed to improve reliability during gas turbine operation, including structural design. Effect of healing agent on crack propagation behavior in TBCs with and without buffer layer was investigated through furnace cyclic test (FCT). Molybdenum disilicide ($MoSi_2$) was used as the healing agent; it was encapsulated using a mixture of tetraethyl orthosilicate and sodium methoxide. Buffer layers with composition ratios of 90 : 10 and 80 : 20 wt%, using yttria stabilized zirconia and $MoSi_2$, respectively, were prepared by air plasma spray process. After generating artificial cracks in TBC samples by using Vickers indentation, FCTs were conducted at $1100^{\circ}C$ for a dwell time of 40 min., followed by natural air cooling for 20 min. at room temperature. The cracks were healed in the buffer layer with the healing agent of $MoSi_2$, and it was found that the thermal reliability of TBC can be enhanced by introducing the buffer layer with healing agent in the top coat.