• 한국염색가공학회지
• /
• 제6권3호
• /
• pp.27-36
• /
• 1994

In order to produce a water repellent surface on polyester fabric, samples were treated in the atmosphere of $CF_4$ glow discharge plasma. The samples used in the study were ployester fabric and poyester film. The purpose of film treatment is for the comparison of hydrophobicity with fabric sample at same treatment condition. Radio frequency(13.56MHz) generator was used as electric source and its in put power is 100 Watt. Water repellency was evaluated by contact angle measurement. Result obtained are as follows. 1) Fiber interstice of original fabric was ana lysed as 0.43$\mu$m, and this value was sufficiently ideal for making water repellent fabric. 2) The most favorable setting position of substrate was the center area between two electrodes. 3) Fabric contact angle was higher than film contact angle at same treatment condition, and its difference was more than 50${\circ}$. And it was incapalbe of fabric contact angle measurement when the film contact angle was less than 90${\circ}$. because the fabric is susceptible to absorption of water by the capillary effect. 4) Fabric contact angle can not revealed the precise defferences of surface hydrophobicity, however, the film contact angle showed the real hydrophobic nature. 5) It was not sufficient method to evaluate the hydrophobicity of fabric surface by merely measure of the water contact angle. 6) It showed high water repellent nature at 0.06 torr of $CF_4$ plasma gas pressure and duration of 45 seconds treatment, and it can not be anticipated more improved nature if the pressure and duration of treatment time were increased.

• 한국염색가공학회지
• /
• 제21권1호
• /
• pp.30-37
• /
• 2009

Studies on plants such as lotus leaf suggested that dual-scale structure could contribute to super-hydrophobicity. We introduced super-hydrophobicity onto poly(ethylene terephthalate)(PET) fabric with dual-scale structure by assembling $TiO_2$ nano sol. PET fabric was treated with $TiO_2$ sol, water-repellent agent using various parameters such as particle size, concentration. Morphological changes by particle size were observed using field emmission scanning electron microscopy(FE-SEM) and AFM measurement, contact angle measurement equipment. The contact angle of water was about 138.5$^{\circ}$, 125.8$^{\circ}$, 125.5$^{\circ}$ and 108.9$^{\circ}$ for PET fabric coated with 60.2nm, 120.1nm, 200nm and 410.5nm $TiO_2$ particles, compared with about 111.5$^{\circ}$ for PET fabric coated with water repellent. When we mixed particle sizes of 60.2nm and 120.1nm by 7:3 volume ratio, the contact angle of water was about 132.5$^{\circ}$. And we mixed particle sizes of 60.2nm and 200nm by 7:3 volume ratio, the contact angle of water was about 141.8$^{\circ}$. Also we mixed particle sizes of 60.2nm and 410.5nm by 7:3 volume ratio, the best super-hydrophobicity was obtained. In this paper, we fabricated various surface structures to the water-repellent surfaces by using four types of $TiO_2$ nano-particles, and we found that the nanoscale structure was very important for the super-hydrophobicity.

• 생명과학회지
• /
• 제23권5호
• /
• pp.637-642
• /
• 2013

본 연구에서는 이러한 설치류 기피제로의 안전성과 친환경적인 소재를 발굴하기 위하여 향이 좋고 기능성이 풍부한 천연오일 13가지를 이용하여 설치류 기피제에 적용가능성에 대해 연구하였다. 먹이 섭취저해율과 서식지 기피활성 시험에서, 세이지(SS), 레몬그라스(CC)에서 높은 기피력을 확인하였다. 또한 설치류에 기피활성이 좋은 4가지 정유를 선발하여 8가지 Gram (-)과 Gram (+)균에 대한 항균활성을 평가한 결과 CC, CZ, SA, SS 에서 몇가지 균을 제외한 대부분의 균에 대한 항균활성을 확인하였다. 따라서 이들 오일을 이용하여 새로운 형태의 기피제로서의 개발이 가능하다.

• Korean Chemical Engineering Research
• /
• 제57권1호
• /
• pp.124-132
• /
• 2019

출발물질로서 TEOS (tetraethoxysilane)와 CTMS (chlorotrimethylsilane)를 사용하여 물과의 가수분해 및 중축합 반응에 의해 발수 코팅 용액을 합성하였다. 또한 이 용액을 PMMA 시트 위에 도포하고 열처리하여 비불소계 발수 코팅 도막을 제조하였다. 코팅 도막은 수접촉각, UV-Vis 투과율 및 미세구조 관찰에 의해 분석되었다. CTMS/TEOS의 몰비를 0.6~1.0으로 변화시켜 제조 된 코팅 도막은 CTMS/TEOS의 몰 비가 0.8일 때 $107^{\circ}$의 최대 접촉각을 나타내었다. 또한 코팅 도막은 CTMS/TEOS의 몰 비가 0.6~0.8일 때 90%의 높은 가시광선 투과율을 보였다. 그러나 CTMS/TEOS의 몰 비가 0.9~1.0인 경우에는 거친 표면의 불균일한 형상으로 인해 코팅 도막은 70% 이하의 낮은 투과율을 보였다.

• 한국건축시공학회지
• /
• 제21권6호
• /
• pp.529-538
• /
• 2021

본 논문은 발수제 첨가 모르타르의 강도 및 발수성에 미치는 다양한 요인 중에서 발수제 종류 및 잔골재 입도에 대한 영향을 검토하고자 하였다. 그 결과 발수제 첨가 시멘트 모르타르의 압축강도는 무첨가 시멘트 모르타르와 비교하여 감소하였고, 올리고머계 발수제 첨가 모르타르의 압축강도는 모노머계 발수제와 비교하여 높게 나타났다. 또한 잔골재 입도에 따른 시멘트 모르타르 압축강도 영향은 크게 나타나지 않았다. 발수제 첨가 모르타르의 접촉각은 무첨가 모르타르와 비교하여 증가하였고, 올리고머계 발수제보다는 모노머계 발수제가 상대적으로 증가하였다. 또한 연마 전후 접촉각은 잔골재 입도에 따라서 상이한 경향을 보이고 있다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.409-414
• /
• 2007

Wettability of solid surfaces with liquids is governed by the chemical properties and the microstructure of the surfaces. We report on the preparation of liquid-repellent surfaces using surface-attached monolayers of perfluorinated polymer molecules on porous silica substrates. A covalent attachment of the polymer molecules to the substrate is achieved by generation of the polymer chains through starting a surface-initiated radical-chain polymerization of a fluorinated monomer. To this, self-assembled monolayers of azo initiators are attached to silica substrates, which are used to kick off the polymerization reaction in situ. The growth of the fluorinated polymer films and the characterization of the obtained surfaces by surface plasmon spectroscopy, XPS, and contact angle measurements is described. It is shown that perfluorinated polymer films can be grown with controlled thicknesses on flat and even on porous silica surfaces, essentially without changing the surface roughness. The combination of the low surface energy coating and the surface porosity allows generation of materials which are both water and oil repellent.

• 셀메드
• /
• 제4권2호
• /
• pp.8.1-8.6
• /
• 2014

Despite the remarkable advancements of the modern medicine, the traditional system of medicine (TSM) still serves as a potential primary health care modality in the in low- and middle-income countries. The recent reports suggest that there is a renewed interest has been observed towards TSM in the developed countries too, because of the adverse side-effect of modern medicines. Medicinal plants have been widely serving as a rich source of therapeutic agent. Ethiopia is one of the most reserves rich countries in the world. It is renowned for well-diversified and natural resources in terms of its unique flora and fauna. Ethiopian deep-rooted tradition and culture largely depends on the usage of plants for their religious ceremonies, impressive festivals, traditional medicinal uses and other basic necessities. The present scrutiny is an attempt to understand the omnipotent nature of an Ethiopian Ethnomedicinal plant called Tinjute [vernacular name (local native language, Amharic); Otostegia integrifolia]. There are several studies suggest that Tinjute can be used as a natural medicine or health-promoting agents for various disorders and ailments. Nevertheless, in Ethiopia, it is renowned as an insect repellent to drive-away insect vector of diseases, particularly mosquitoes in the early evening. However, there are many more issues and challenges which must be urgently addressed to scientifically formulate various potent, efficacious, safe and highly selective phytotherapeutic agents and insects' repellent from the Tinjute plant in the near future.

• 농약과학회지
• /
• 제4권2호
• /
• pp.18-20
• /
• 2000

민들레(Teraxacum platycerpum leaf), 소나무(Pinus densiflora leaf), 쑥(Artemisia prinseps, leaf), 부추(Allium tuberosum leaf), 결명초(Cassia obtussifolia, whole plant), 고삼(Sophora angestifolia, root), 백부근(Stemonae sessilifolia, root), 인동(Lonicera japonica, stem, leaf, flower) 및 귤(Clivia miniata, left)등 9종의 자생식물(시료11종)의 메탄올 추출물이 흰줄숲모기와 바퀴에 대한 기피효과 실험을 실행하였다. 그결과 흰줄숲모기에 대해서는 소나무잎 민들레잎 부추 잎 및 인동꽃 등의 메탄올 추출물이 기피효과가 우수하였다. 한편 바퀴에 대한 이들의 기피효과에서는 인동잎이 좋았으나 일반적으로 흰줄숲모기에 비해 기피효과가 떨어졌다.

• 대한가정학회지
• /
• 제20권3호
• /
• pp.19-24
• /
• 1982

This study was carried out to investigate the relationship between the water resistance and the air permeability. The results are as follows; 1. In case of the water proofing fabrics, We cannot find that there is any relationship between the water resistance and the air permeability according to the kinds of finishing, while in case of the water repellent finished fabries, we can find that there is a correlationship between them, especially the hydrostatic pressure and the air permeability are found to have negative correlation. 2. In case of the water proofing fabrics, the relationship between the water resistance and the air permeability is not affected by the thickness of the fabrics. On the other hand, in case of the water repellent finished fabrics, the relationship between them is affected by the thickness of the fabrics. Especially, the relationship between the hydrostatic pressure and the air permeability as well as the relationship between the water repellency and the air permeability is effect much by the thickness of the fabrics, too. 3. In case of the water proofing fabrics, the relationship between the water resistance and the air permeability is not affected by fabric count. On the otherhand, in case of the water repellent finished fabrics, the relationship between them is affected by the fabric count. Especially, the relationship between hydrostatic pressure and the air permeability, and the relationship between the water proof and the air permeability are affected much by fabric count.

• Molecular & Cellular Toxicology
• /
• 제3권1호
• /
• pp.68-75
• /
• 2007

[ $\alpha$ ]-Terpinene has been known as a repellent against the mosquito Culex pipiens pallens Coquillett based on a human forearm bioassay. $\alpha$-Terpinene showed significantly greater repellency than a commercial formulation, N, N-diethyl-m-methylbenzamide (deet). In this study, skin and eye sensitivity of $\alpha$-terpinene (2%) was examined with bioassays using white New Zealand rabbits. There were somewhat gross and histological changes observed in these treatments. Eye irritancy assays examined gross changes to cornea, iris and conjuctiva, and histological changes to smear of ocular discharge and eye tissue. Treated rabbits were divided into two cohorts, a saline washed cohort (W) or a non-washed cohort (NW). Opacity of cornea and redness, chemosis and discharge of conjuctiva were observed in both cohorts, but disappeared within 4 and 10 days in W and NW, respectively. Main components of ocular discharges were fibrin, epithelial or epitheloid cells, lymphoid cells, erythrocytes and granulocytes. These abnormal cellular components disappeared within 4 days and 10 days in W and NW, respectively. No permanent histological differences were observed between the two cohorts. However, severe irritation was determined as 57.2 of I.I.O.I value on the first day after treatment. These findings indicate a spray-type solution containing 2% $\alpha$-terpinene may serve as an alternative mosquito repellent and further studies need to reduce the eye irritation with formulation changes.