• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.137-137
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• 2003

Conducting PPy/PVA composite and pure PPy gas sensors were prepared by in-situ vaporstate polymerization method in a vaporization chamber under N2 condition, by exposing the pre-coated electrode with PVA/FeC13 to distilled pyrrole monomer. The various electrical sensing behaviors of both types of sensors were systematically investigated by a flow measuring system including mass flow controller (MFC) and bubbling bottle. The FT-Raman spectroscopy of vapor state polymerized PPy was identical to that of chemically polymerized PPy, confirming the same chemical structure. Both types of sensors had positive sensitivity when exposed to methanol gas. The sensitivity varied linearly with gas concentration in the range of 50ppm to 1059ppm. The detection limit of PPy/PVA sensor was believed to be as low as 10ppm. The sensitivity of PPy/PVA composite sensor was higher than that of pure PPy sensor. Both the response time and recovery time of PPy/PVA composite sensors were longer than those of pure PPy sensors. The thickness of the sensing film affected the sensitivity this way that the sensor having thinner film had higher sensitivity, indicating that the resistance of polymer film involved in the sensing behavior was bulk resistance rather than surface resistance. The reproducibility of PPy/PVA composite sensor was excellent during eight on-off cycles by switching between N2 and 3000ppm methanol gas. The sensitivity of PPy/PVA composite sensor was only maintained for two weeks, while the sensitivity of pure PPy sensor was maintained over two months.

• Korean Chemical Engineering Research
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• 제43권5호
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• pp.603-608
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• 2005

주조된 매크로 다공성 poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) 막대를 간단한 주형 과정을 거쳐서 실험실 내 튜브모양의 주형인 크로마토그래피 칼럼($4.6{\times}100mm$)을 사용하여 자유 라디칼 중합에 의해 만들었다. 이는 에폭시 그룹이 유도된 일체형 칼럼과 황산을 이용한 에폭시드 그룹의 화학적인 변형과정을 이용하였다. 단량체 및 포로겐(세공을 생성하는 물질)의 비율, 온도 등 중합반응의 조건을 변화시켜서 세공크기를 조절하여 물질의 체류시간에 영향을 미쳤다. 본 연구에서는 주조된 일체형 칼럼을 이용하여 카페인과 트립토판을 분리하였으며, 중합원료조성이 일체형 칼럼의 효율과 선택도 그리고 분리도에 미치는 영향을 고찰하였다.

• Membrane and Water Treatment
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• 제8권4호
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• pp.311-321
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• 2017

Hydrophilic and high modulus PPTA molecules were incorporated into PVDF matrix via the in situ polymerization of PPD and TPC in PVDF solution. PPTA/PVDF/NWF blend membrane was prepared through the immersion precipitation phase inversion method and nonwoven coating technique. The membrane integrated technology including PPTA/PVDF/NWF blend membrane and reverse osmosis (RO) membrane was employed to treat the polyester/viscose spunlace nonwoven process wastewater. During the consecutive running of six months, the effects of membrane integrated technology on the COD, ammonia nitrogen, suspended substance and pH value of water were studied. The results showed that the removal rate of COD, ammonia nitrogen and suspended substance filtered by PPTA/PVDF blend membrane was kept above 90%. The pH value of the permeate water was about 7.1 and the relative water flux of blend membrane remained above 90%. After the deep treatment of RO membrane, the permeate water quality can meet the water circulation requirement of spunlace process.

• Advances in materials Research
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• 제2권4호
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• pp.209-219
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• 2013

We have described primary studies on conductivity and molecular weight of polyaniline separately in the electric and magnetic fields when it is used in a field effect experimental configuration. We report further studies on doped in-situ deposited polyaniline. First we have chemically synthesized polyaniline by ammonium peroxodisulfate in acidic aques and organic solutions at different times. Then we measured mass and conductivity and obtained the best time of polymerizations. In continue, we repeated these reactions separately under different electric and magnetic fields in constant time and measured mass and conductivity. The polyaniline is characterized by gel permeation chromatography (GPC), UV-Visible spectroscopy and electrical conductivity. High molecular weight polyanilines are synthesized under electric field, $M_w$ = 520000-680000 g/mol, with $M_w/M_n$ = 2-2.5. The UV-Visible spectra of polyanilines oxidized by ammonium peroxodisulfate and protonated with dodecylbenzenesulfonic acid (PANi-DBSA), in N-methylpyrolidone (NMP), show a smeared polaron peak shifted into the visible. Electrical conductivity of polyanilines has been studied by four-probe method. The conductivity of the films of emeraldine protonated by DBSA cast from NMP are higher than 500 and 25 S/cm under 10 KV/m of potential) electric field and 0.1 T magnetic field, respectively. It shows an enhanced resistance to ageing too. By the next steps, we carried chemical polymerization at the best electric and magnetic fields at different times. Finally, resulted in finding the best time and amount of the fields. The longer polymerization time and the higher magnetic field can lead to degradation of polyaniline films and decrease conductivity and molecular mass.

• 공업화학
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• 제29권4호
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• pp.363-368
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• 2018

Polyoxometalates (POMs)는 뛰어난 특성과 전기 화학 응용 분야에 대한 많은 잠재력을 가지고 있다. POM은 매우 잘 녹는 성질 때문에 전기화학 소자에서 POM의 잠재력을 최대한 활용하기 위해서는 다양한 기능성 재료에 POM을 고정화하는 과정이 필수이다. 본 논문에서는 우리는 최근 개발된 고정화 방법인 나노 카본 및 전도성 고분자와 같은 전도성 나노 물질에 POM을 도입하는 기술들에 대해서 논하고자 한다. Langmuir-Blodgett 기술, 층별 자기 조립 및 전기화학 in-situ 중합을 사용하여 전도성 고분자 매트릭스 및 POM을 나노 카본으로 도입할 수 있는 다양한 고정화 전략을 소개한다. 또한 우리는 POM의 응용 분야인 물 산화용 전극 촉매, 리튬 이온 배터리, 슈퍼커패시터 및 전기화학적 바이오 센서 등의 다양한 전기 화학 응용 분야를 다룬다.

• 한국응용과학기술학회지
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• 제27권4호
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• pp.445-451
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• 2010

To prepare very stable acrylic type emulsion having a visible ray absorption property, in-situ preparation technique of $Cu_xS$ nanoparticle was adopted. Firstly, the acylic emulsions of methyl methacrylate(MMA), butyl acrylate(BA), and acrylonitrile(AN) were synthesized by pre-emulsion polymerization at $60^{\circ}C$ in the presence of anionic surfactant. Secondly, $Cu_xS$ nanocomposited emulsions were directly prepared in the prepolymerized acrylic emulsion with $CuSO_4$ at $50^{\circ}C$. The presnce of $Cu_xS$ nanoparticle in emulsion was confirmed by SEM and EDS. The final $Cu_xS$ nanocomposited emulsion showed an olive-green colour and good emulsion stability up to 1 month. In addition the PET films coated with our $Cu_xS$ nanocomposited emulsion absorbed effectively the visible ray.

• Steel and Composite Structures
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• 제24권1호
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• pp.15-22
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• 2017

A green biosynthesis method is described for the preparation of Polyaniline (PANI)-cerium dioxide ($CeO_2$) nanocomposites in different media via in-situ oxidative polymerization procedure. The effect of various media including use of HCl, Lemon Juice, Beverage, White Vinegar, Verjuice and Apple vinegar extracts on the particles size, morphology as well as the conductivity of $PANI-CeO_2$ nanocomposites was investigated. The electron-withdrawing feature of $CeO_2$ increases doping level of PANI and enhances electron delocalization. These cause a significantly blue shift of C = C stretching band of quinoid from $1570cm^{-1}$ to $1585cm^{-1}$. The optical properties of the pure material and polymeric nanocomposites as well as their interfacial interaction in nanocomposite structures analyzed by UV-visible spectroscopy. The DC electrical conductivity (${\sigma}$) of as-prepared HCl doped PANI and a $PANI-CeO_2$ nanocomposite measured by a four-probe method at room temperature was studied.

• 폴리머
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• 제24권2호
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• pp.276-280
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• 2000

폴리아크릴로니트릴 (PAN) 직물을 매트릭스로 하여 전도성고분자인 폴리피롤(PPy)과 전도성 복합재료 직물을 제조하였다. 복합재료의 제조는 PAN 직물을 피롤과 산화제를 포함하는 용액에 일정 시간동안 함침하여 직물상에서 전도성 고분자의 중합을 in-situ로 유도하는 방법을 이용하였다. 복합재료의 물성을 최적화 하기 위한 반응 조건을 설정하였으며, 이때 arylsulfonate 계통의 도판트를 부가적으로 첨가하여 이들이 복합재료의 물성에 미치는 영향을 검토하였다. 본 연구에서 실험한 다양한 종류의 도판트 중에서 antraquinonesulfonate (AQSA)가 부가적으로 첨가된 전도성 PAN 직물이 가장 우수한 전기전도도와 열적 안정성 및 세탁 견뢰도를 나타내었다.

• Carbon letters
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• 제13권4호
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• pp.243-247
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• 2012

A fabrication method to improve the processability of thermoplastic carbon nanotube (CNT) mat composites was investigated by using in-situ polymerizable and low viscous cyclic butylene terephthalate oligomers. The electrical conductivity of the CNT mat composites strongly depended on the compression pressure, and the trend can be explained in terms of two cases, low and high compression pressure, respectively. High CNT mat content in the CNT mat composites and the surface of the CNT mat composites with fully contacted CNTs was achieved under high compression pressure, and direct contact between four probes and the surface of the CNT mat composites with fully contacted CNTs gave resistance of $2.1{\Omega}$. In this study the maximum electrical conductivity of the CNT mat composites, obtained under a maximum applied compression pressure of 27 MPa, was 11 904 S $m^{-1}$, where the weight fraction of the CNT mat was 36.5%.

• 폴리머
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• 제27권1호
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• pp.75-83
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• 2003

다이시아네이트-점토 나노복합재료(dicyantate-clay nanocomposite)를 개질제의 종류와 cation exchange capacity (CEC)의 차이에 따라 용융 in-situ법에 의하여 제조하였고 이들의 물성과 분산을 측정하였다. 다양한 층간 삽입물을 함유하여 다양한 층간거리와 적층밀도를 갖는 montmorillonite (MMT)에 따라 다양한 구조의 나노복합재가 제조되었다. 사용된 다이시아네이트와 점토는 각각의 친화성에 따라 실리케이트 내부로의 삽입정도가 달라졌다. 다이시아네이트-점토 나노복합재료의 분산은 CEC와 개질제의 지방족 사슬길이에 의존하였으며 더 낮은 CEC를 가지고 지방족 사슬의 길이가 짧은 것이 좀 더 분산된 구조를 가지는 것으로 측정되었다. 또한 사용된 개질제에 고분자와의 반응성이 부여되면 층간 삽입이 더욱 용이한 것으로 나타났다. 다이시아네이트 나노복합재료의 전단탄성율은 반응성을 가지며 박리된 구조를 가지는 경우에 더 향상된 물성을 가지는 것으로 나타났다.