• 제목/요약/키워드: Lipid thin film

검색결과 14건 처리시간 0.029초

실리콘 웨이퍼 위에 제작된 DLPC 지질막의 전기적특성 (Elctrical Properties of DLPC Lipid Membrane Fabricated on the Silicon Wafer)

  • 이우선;김충원;이강현;정용호;김남오;김상용
    • 한국전기전자재료학회논문지
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    • 제11권12호
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    • pp.1115-1121
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    • 1998
  • MLS capacitor with lipid ultra thin films were deposited by Langmuir-Blodgett (LB) method on the silicon wafer. The current versus voltage and capacitance versus voltage relationships are depend on the applied voltage, electrode area and electrode materials. LB films deposited were made of L-$\alhpa$-DLPC, the 1 layer’s thickness of 35${\AA}$ was measured by ellipsometer. And MLS capacitor with different electrode materials, the work function of these materials was investigated to increase the leakage current. The result indicated the lower leakage current and very high saturation value of capacitance was reached within 700-800 pF when the two electrode was Ag. And $\varepsilon$1, $\varepsilon$2 versus photon energy showed good film formation.

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DLPC 인지질 단분자막의 변위전류 특성 연구 (I) (A Study on Displacement Current Characteristics of DLPC Monolayer (I))

  • 송진원;이경섭;최용성
    • 전기학회논문지
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    • 제56권1호
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    • pp.117-122
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    • 2007
  • LB method is one of the most interesting technique to arrange certain molecular groups at precise position relative to others. Also, the LB deposition technique can fabricate extremely thin organic films with a high degree of control over their thickness and molecular architecture. In this way, new thin film materials can be built up at the molecular level, and the relationship between these artificial structures and the properties of materials can be explored. In this paper, evaluation of physical properties was made for dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of phospolipid monomolecular DLPC. Lipid thin films were manufacture by detecting deposition for the accumulation and the current was measured after the electric bias was applied across the manufactured MIM device. It is found that the phospolipid monolayer of dielectric relaxation takes a little time and depend on the molecular area. When electric bias is applied across the manufactured MIM device by the deposition condition of phospolipid mono-layer, it wasn't breakdown when the higher electric field to impress by increase of deposition layers.

Considerations for Making Liposomes by Thin Film-Hydration Method

  • Gyeong-Tak Byeon;Ji-Yoon Son;Jeongsoo Yoo
    • 대한방사성의약품학회지
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    • 제8권2호
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    • pp.151-156
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    • 2022
  • Liposomes are bilayered particles that are surrounded by an aqueous solvent with amphiphilic substances such as phospholipids. Liposomes have the potential to overcome the limitations of physiochemical properties of existing drugs, and are therefore widely used in research for the treatment of many diseases, especially cancer. Currently, there are many liposome manufacturing methods that use various lipids and amphiphiles. Among them, the thin film-hydration method is a traditional and very simple method to prepare liposomes by hydrating a dry lipid film in an aqueous solvent, which has been widely used in the laboratory until recently. Recently, approaches to new nuclear imaging agents and radiotherapy by loading radioactive isotopes inside liposomes have been actively studied. In this review, we would like to discuss considerations for preparing liposomes using the thin film-hydration method.

Cellulose를 이용한 가식성(可食性) Film의 제조와 물리적 특성연구 (Preparation of Cellulose-Based Edible Film and its Physical Characteristics)

  • 송태희;김철재
    • 한국식품과학회지
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    • 제28권1호
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    • pp.1-7
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    • 1996
  • Hydrocolloid film에 lipid 액을 입혀 제조한 film A와 hydrocolloid 용액에 beeswax의 함량과 용해 상태를 달리하여 제조한 film B와 C의 물리적 특성을 검토해 본 결과, 제조에 있어서는 film A보다 film B와 C의 제조가 용이하였다. 세가지 film의 두께는 0.03 mm 정도로 유의적인 차이를 나타내지 않았으며, 1-3%의 수분함량과 59-68%의 지방을 함유한 film으로 세 film 모두 백색을 나타내었다. 인장강도는 film A가 우수하였으며, 투습도에서는 lipid 액의 뚜렷한 효과로 감소하였으며 film A와 B는 유의적인 차이를 나타내지 않았다. 한편 냉동전후의 투습도에서 film A는 유의적인 차이를 나타내지 않았으나, film B와 C는 냉동 후의 투습도가 유의적으로 감소하였다. 산소투과도는 film A와 C가 유의적인 차이를 나타내지 않았다. 전자현미경으로 film의 표면특성을 관찰한 결과, film A는 지방구의 분포가 일정하였으나 B와 C는 지방구의 편재를 볼 수 있었으며 1년 저장 후 film A는 bilayer층의 delamination을 나타내는 것으로 보아 전반적인 물리적 특성은 film A가 우수하나 장기저장에 있어서는 보다 제조법이 용이한 film B와 C를 선택하는 것이 바람직할 것으로 보이며, film B와 C의 균일하지 못한 표면 형상을 개선하는 방법과 투습도 및 산소투과도를 감소시키는 것이 앞으로 개선할 과제로 여겨진다.

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Application of multimodal surfaces using amorphous silicon (a-Si) thin film for secondary ion mass spectrometry (SIMS) and laser desorption/ionization mass spectrometry (LDI-MS)

  • Kim, Shin Hye;Lee, Tae Geol;Yoon, Sohee
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.384.1-384.1
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    • 2016
  • We reported that amorphous silicon (a-Si) thin film provide sample plate exhibiting a multimodality to measure biomolecules by secondary ion mass spectrometry (SIMS) and laser desorption/ionization mass spectrometry (LDI-MS). Kim et al.1 reported that a-Si thin film were suitable to detect small molecules such as drugs and peptides by SIMS and LDI-MS. Recently, bacterial identification has been required in many fields such as food analysis, veterinary science, ecology, agriculture, and so on.2 Mass spectrometry is emerging for identifying and profiling microbiology samples from its advantageous characters of label-free and shot-time analysis. Five species of bacteria - S. aureus, G. glutamicum, B. kurstaki, B. sphaericus, and B. licheniformis - were sampled for MS analysis without lipid extraction in sample preparation steps. The samples were loaded onto the a-Si thin film with a thickness of 100 nm which did not only considered laser-beam penetration but also surface homogeneity. Mass spectra were recorded in both positive and negative ionization modes for more analytical information. High reproducibility and sensitivity of mass spectra were demonstrated in a mass range up to mass-to-charge ratio(m/z) 1200 by applying the a-Si thin film in mentioned above MS. Principle component analysis (PCA) - a popular statistical analysis widely used in data processing was employed to differentiate between five bacterial species. The PCA results verified that each bacterial species were readily distinguished and differentiated effectively from our MS approach. It shows a new opportunity to rapid bacterial profiling and identification in clinical microbiology. More details will be discussed in the presentation.

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DMPC 인지질 단분자막의 변위전류 특성 연구 (II) (A Study on Displacement Current Characteristics of DMPC Monolayer (II))

  • 송진원;이경섭;최용성
    • 전기학회논문지
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    • 제56권2호
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    • pp.343-348
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    • 2007
  • The physical properties of DMPC monolayer were made for dielectric relaxation phenomena by the detection of the surface pressures and displacements current. Lipid thin films were deposited by accumulation and the current was measured after the electric bias across the manufactured MIM device. It is found that the phospolipid monolayer of dielectric relaxation takes a little time and depend on the molecular area. When electric bias is applied across the manufactured MIM device by the deposition condition of phospolipid mono-layer, it wasn't breakdown when the higher electric field to impress by increase of deposition layers.

Room Temperature Growth of Magnetite Films on Arachic Acid Monomolecular Layers

  • Ishihara, Takashi;Kitamoto, Yoshitaka;Shirasaki, Fumio;Abe, Masanori
    • The Korean Journal of Ceramics
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    • 제6권4호
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    • pp.401-404
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    • 2000
  • Mimicking the bacterial synthesis of magnetosomes, in which the functionalized surface of a cytoplasmic (lipid) membrane is considered to be stimulating the crystal growth of magnetite, we have successfully grown magnetite films at $30^{\circ}C$ using an arachic acid monomolecular layer as a functionalized surface. The lipid monomolecular layer was spread on an aqueous solution of FeCl$_2$ which was oxidized by flowing a mixed gas, with ratio $O_2$/$N_2$=1/2000, on the surface of the lipid layer. Mossbauer and X-ray diffraction analyses revealed that the Fe$_3$O$_4$ films contain small amounts of ferric hydroxyl impurity phases of ${\alpha}$-FeOOH and ${\tau}$-FeOOH. This is because the oxygen partial pressure at the ferrite/aqueous interface changed as the film (through which the gas penetrated) increased in thickness. Methods to obtain single phase magnetite films are proposed.

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Moving Wall형 LB법에 의해서 제작된 DLPC 지질막의 누적특성 (The Deposition Characterization of DLPC Lipid Membrane by Moving Wall Type LB Methode)

  • 정용호;이우선;김남오;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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    • pp.342-345
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    • 1997
  • We fabricated the sample of u1tra thin lipid membrane(L-${\alpha}$-DLPC ) by LB methode. The $\pi$-A isotherm of the DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. For good property of lipid monolayer film, it was necessary for the lower speed of compressing, and 40${\mu}\ell$ of solutions for spreading. The molecular arrangement of deposited films were evaluated by measuring the absorption, transmitance and intensity with the UV spectrophotometer. The Y-type multilayers prepared at 50mN/m showed weaker than Z-type. So we found building-up of structurally high quality LB films is essential to study properties of the films and to get reproducible data.

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Moving wall형 LB법에 의하여 제작된 DLPC 지질막의 누적특성 (The Deposition Characterization of DLPC Lipid Membrane Fabricated by Moving wall Type LB Method)

  • 이우선;최창주;정용호;김남오;이경섭;장의구;김태성
    • E2M - 전기 전자와 첨단 소재
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    • 제10권6호
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    • pp.548-554
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    • 1997
  • We fabricated the sample of ultra thin lipid membrane(L-$\alpha$-DLPC) by LB method. The $\pi$-A isotherm of the DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. For the good property of lipid monolayer film, it was necessary to prepare at the lower speed of compressing, with an appropriate volume of solutions for spreading. Absorption, transmitance and intensity with the UV spectrophotometer were measured. The Z-type multilayers showed good characteristics better than Y-type. So we found building-up of structurally high quality LB films is essential to study properties of the films and to get reproducible data.

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Enhancing Raw Bovine Milk Quality using Ultraviolet-C (UV-C) Irradiation: A Microbial and Lipid Peroxidation Study

  • Davids Makararpong;Supawan Tantayanon;Chupun Gowanit;Jiranij Jareonsawat;Sukuma Samgnamnim;Sirirat Wataradee;Henk Hogeveen;Chaidate Inchaisri
    • 한국축산식품학회지
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    • 제44권2호
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    • pp.372-389
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    • 2024
  • This study investigated the efficacy of ultraviolet-C (UV-C) irradiation in enhancing the quality of raw bovine milk by targeting microbial populations and lipid peroxidation, both of which are key factors in milk spoilage. We categorized the raw milk samples into three groups based on initial bacterial load: low (<3 Log 10 CFU/mL), medium (3-4 Log 10 CFU/mL), and high (>4 Log 10 CFU/mL). Using a 144 W thin-film UV-C reactor, we treated the milk with a flow rate of 3 L/min. We measured the bacterial count including standard plate count, coliform count, coagulase-negative staphylococci count, and lactic acid bacteria count and lipid peroxidation (via thiobarbituric acid reactive substances assay) pre- and post-treatment. Our results show that UV-C treatment significantly reduced bacterial counts, with the most notable reductions observed in high and medium initial load samples (>4 and 3-4 Log 10 CFU/mL, respectively). The treatment was particularly effective against coliforms, showing higher reduction efficiency compared to coagulase-negative staphylococci and lactic acid bacteria. Notably, lipid peroxidation in UV-C treated milk was significantly lower than in pasteurized or untreated milk, even after 72 hours. These findings demonstrate the potential of UV-C irradiation as a pre-treatment method for raw milk, offering substantial reduction in microbial content and prevention of lipid peroxidation, thereby enhancing milk quality.