• Composites Research
• /
• v.34 no.6
• /
• pp.434-439
• /
• 2021

Graphene and polyaniline with thermoelectric properties are one of the potential substitutes for inorganic materials for flexible thermoelectric applications. In this study, we studied the photo-induced thermoelectric effect of graphene-polyaniline composites. The graphene-polyaniline composites were synthesized by introducing an amine functional group to graphene oxide for covalently connecting graphene and polyaniline, reducing the graphene oxide, and then polymerizing the graphene oxide with aniline. Graphene-polyaniline composites were prepared by changing the aniline contents in order to expect an optimal photothermoelectric effect, and their structural properties were confirmed through FT-IR and Raman analysis. The photocurrent and photovoltage characteristics were analyzed by irradiating light asymmetrically without an external bias and the current and voltage with various aniline contents. While the photocurrent trends to the electrical conductivity of the graphene-polyaniline composites, the photovoltage was related to the temperature change of the graphene-polyaniline composite, which was converted into thermal energy by light.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2011.04a
• /
• pp.39-39
• /
• 2011

산림자원의 부족현상이 갈수록 심화됨에 따라, 재활용폐지를 원료로 활용하는 비율이 증가되고 있으며, 재활용 폐지의 품질도 지속적으로 악화되어 제지 환경이 점점 어려워지고 있다. 이에 최근에 개발되어 지대지, 라이너 판지등에 적용하여 강도상승 목적으로 사용중인 호프만계 폴라비닐아민에 대한 성능평가 결과를 고찰하고자한다. 호프만계 폴리비닐아민의 가장 큰 장점은 투입량을 증량하여도 종이의 Formation에 악영향을 마치지 않고 효과적으로 내절도, 파열강도등 강도적 적성이 향상되므로 응용 범위가 점차 확대되고 있다. 이와 더불어 제지환경이 점점 어려워짐에 따라, 보류 및 탈수 향상등 제지 공정개선제로 많이 사용되는 파우더 및 에멀젼의 성능 고도화가 절실히 요구되고 있으며, OCI-SNF의 개선 사례를 살펴보고자한다.

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1997-1999
• /
• 2002

고분자 주쇄(Main chain)의 소수성을 가지는 플루오르 그룹을 배제시킨 습도 민감성 폴리이미드를 합성 및 이미드화 하였고, 이를 이용한 초고참도 습도 센서를 제작 및 측정하였다. 사용된 폴리이미드는 다이아민계로 Oxydianyline(ODA)와 다이안하이드라이드계로 Pyromellitic dianhydried(PMDA)를 유기용매 Dimethyla cetamide(DMAc) 하에서 폴리이미드 전구체 (Polyamic acid)를 합성하였으며, 진공 및 승온 조건에서 유기용매를 제거하여 이미드화(Imidization) 반응을 진행시켜 제조하였다. 본 습도 센서는 정전용량형 고감도 습도 센서로 디자인되었으며 실리콘 웨이퍼상에서 일반적인 반도체 공정을 이용하여 구현하였다. 본 습도 센서는 센서 크기와 유효면적, 감습층의 두께를 주요 변수로 설정하였으며 이에 따른 습도 민감성 효과를 평가 및 분석하였다. 측정 결과 유효면적 70%, 감습층 두께 $1.1{\mu}m$ 로 제작된 습도 센서는 상대숨도$20%{\sim}90%$ 영역에서 캐패시턴스와 선형적 상관관계를 보여주고 있으며, 습도 민감도는 3.9 pF/%RH 클 얻을 수 있었다.

• Journal of Adhesion and Interface
• /
• v.19 no.1
• /
• pp.19-29
• /
• 2018

Polydopamine coating is one of the most straightforward and widely used method for surface modification inspired by adhesiveness of mussel foot protein contributed by co-existence of catechol and amine. This technique has been utilized not only in surface modification but other numerous fields of study as well. For the past decade, the subject of polydopamine has been thoroughly studied since the initial polydopamine research published in 2007, including its chemical structure, coating conditions, and material characteristics. In this study, we report the current trends and progress of polydopamine coating methods, the newly developing areas of polydopamine related research such as using dopamine derivatives and polyphenolic compounds, improvement of various functionalization and application of polydopamine coating, and explain the state of current attempts to discover the chemical mechanism, structure, and properties of polydopamine.

• Polymer(Korea)
• /
• v.32 no.6
• /
• pp.509-515
• /
• 2008

The aminated polypropylene melt blown ion exchange fibers were synthesized with acrylic acid monomer onto polypropylene melt blown fibers by radiation-induced polymerization and subsequent amination. Degree of grafting was increased with increasing the acrylic acid monomer concentration and total dose. The highest degree of grafting was obtained 140% at a monomer concentration of 20 v/v% acrylic acid and total dose of 4 kGy. Optimum condition of Mohr's salt was 5.0 $\times10^{-3}$ M. Degree of amination was increased with increasing degree of grafting. Water content was about 1.5 times higher than that of trunk polymer. The maximum ion-exchange capacity was 7.3 meq/g which was 2$\sim$3 times higher than a commercial ion exchange fiber. The average pore size was decreased and BET surface area was increased in order of PPmb, PPmb- g- AAc and APPmb- g- AAc. The average pore size and BET surface area of synthesised fibers were $366.1\;{\AA},\;3.71m^2/g,\;143.3\;{\AA},\;4.94m^2/g,\;40.97\;{\AA},\;8.98m^2/g$, respectively.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2008.05a
• /
• pp.214-218
• /
• 2008

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.4
• /
• pp.263-271
• /
• 2009

This study evaluated the flocs forming characteristics in the mixing zone to increase the coagulation effect in the drinking water plant. As a measuring tool of formed flocs, on-line particle dispersion analyzer (iPDA) was used in Y drinking water plant. To evaluate the forming flocs, many parameters such as poly amine, coagulant dosing amount, raw water turbidity, and pH was applied in this study. During the periods of field test, poly aluminium chloride (PACl) as a coagulant was used. With the increase of the raw water turbidities, poly amine was also added as one of aids for increasing in coagulation efficiency. The turbidity and pH of raw water was ranged from 7 to 9 and from 25 to 140 NTU, respectively. The increasing of raw water turbidity brought the bigger floc sizes accordingly. From a regression analysis, $R^2$ value was 0.8040 as a function of T, raw water turbidity. Floc size index (FSI) was obtained from a correlation equation as follows; FSI = 0.9388logT - 0.3214 Also, polyamine gave the bigger flocs the moment it is added to the coagulated water in the rapid mixing zone. One of parameters influencing the floc sizes was the addition of powdered active carbon(PAC) in the mixing zone. In case of higher turbidity of raw water, $R^2$ value was 0.9050 in the parameters of [PACl] and [PAC]; FSI = $0.0407[T]^{0.324}[PACI]^{0.769}[PAC]^{0.178}$ On-line floc monitor was beneficial to evaluate the flocs sizes depending on the many parameters consisting raw water properties, bring the profitable basic data to control the mixing zone more effectively.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 2002.11a
• /
• pp.233-240
• /
• 2002

식물체내에 미량으로 생성되어 식물체내의 생리적인 작용을 크게 변화시켜 식물의 생장과 발육을 촉진 또는 억제하는 생장조절물질의 종류로는 Auxin, Cytokinin, Gibberellin, Abscisic acid, Ethylene, Brassinosteroids, Polyamine, Jasmonates 등이 있다(byun, 1982). Gibberellin은 포도의 경우 씨 없는 포도(무핵과)를 만드는 기술이 델라웨어 품종을 주축으로 실용화 되어있고(Weaver, 1972) 배의 행수와 신고 품종에서는 Gibberelli paste처리에 으해 5∼7일의 숙기 촉진과 함께 과중의 비대에 효과가 있으나 이러한 Gibberellin 계통의 식물생장조절제 사용으로 과실의 경도가 낮아지고 부패과, 밀병 및 분질화 등의 생리장해가 발생하고 보구력이 크게 떨어지는 단점이 있다. (중략)

• Korean Journal of Microbiology
• /
• v.28 no.4
• /
• pp.290-296
• /
• 1990

Putrescine, spermidine, and spermine were found to persent in Methylobacterium extorquens AM1 growing on methanol, succinate, glucose, or nutrient broth as an energy source. Spermidine was found to be a major polyamine in cells growing on methanol or succinate, while putrescine to be the one in nutrient broth-grown cells. The overall content of polyamines in cells growing on glucose was less than that in cells growing on other substrates. Spermine was the most abundant polyamine in glucose-grown cells. Accumulation of polyamines in M. extorquens AM1 was maximal at the mid-exponential or early stationary phase during growth on each substrate. The effect of polyamines added into the medium on the polyamine composition in M. extorquens AM1 was variable. Each polyamine added into the nutrient broth medium was found to increase the amount of the respective polyamine in the cell. Exogeneously added polyamines had no effect on the growth of M. extorquens AM1.

• YAKHAK HOEJI
• /
• v.41 no.4
• /
• pp.414-420
• /
• 1997

A rapid and sensitive high performance liquid chromatographic method with UV detection for the analysis of polyamines(putrescine, spermidine, spermine) has been developed. The benzoyl chloride derivatives of putrescine, spermidine and spermine are separated on a mc-Bondapak C18 reverse-phase column with 50% methanol as the mobile phase. This method was applied to the analysis of polyamines in the serum of normal human and uterine cancer patients. The results show that the mean level of polyamines in cancer patients serum is much higher than that in normal human serum.