• 멤브레인
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• 제10권2호
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• pp.66-74
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• 2000

In consideration that a high tensile strength and ion exchange capacity are maintained as the swelling of membrane is controlled by the coagulation of PSf with the introduction of ion exchange groups and PPSS without the introduction of ion exchange groups, the block copolymer of PSf and PPSS were synthesized. The cation exchange membrane was prepared by sulfonation with CSA and casted. The synthesized block copolymer and cation exchange membrane were characterized by FT-IR and their thermal stability was confirmed by TGA. The optimum sulfonation could be accomplished at a mole ratio of BPSf to CSA 1:3. The best electrochemical properties obtained by the optimal condition were area resistance of 4.37 $\Omega$ㆍ$\textrm{cm}^2$, ion exchange capacity of 1.71 meq/g dry membrane, water content of 0.2941 g $H_2O$/g dry membrane, and fixed ion concentration of 5.81 meq/g $H_2O$. When GBL was used as an additive, area resistance was increased by 13.7 % and ion exchange capacity was increased by 14.6%. When the membrane was fabricated in a form of composite using non woven cloth as a support. the tensile strength of membrane could be improved, but the electrochemical characteristics were not influenced.

• ETRI Journal
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• 제36권1호
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• pp.106-115
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• 2014

In this work, the coplanar waveguide is fabricated on a PES (poly[ether sulfone]) substrate for application to a flexible monolithic microwave integrated circuit, and its RF characteristics were thoroughly investigated. The quality factor of the coplanar waveguide on PES is 40.3 at a resonance frequency of 46.7 GHz. A fishbone-type transmission line (FTTL) structure is also fabricated on the PES substrate, and its RF characteristics are investigated. The wavelength of the FTTL on PES is 5.11 mm at 20 GHz, which is 55% of the conventional coplanar waveguide on PES. Using the FTTL, an impedance transformer is fabricated on PES. The size of the impedance transformer is $0.318mm{\times}0.318mm$, which is 69.2% of the size of the transformer fabricated by the conventional coplanar waveguide on PES. The impedance transformer showed return loss values better than -12.9 dB from 5 GHz to 50 GHz and an insertion loss better than -1.13 dB in the same frequency range.

• 센서학회지
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• 제21권4호
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• pp.256-262
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• 2012

Hyaluronic acid(HA) hydrogels were synthesized by immersing HA microbeads in phosphate buffered saline solutions having different pH levels to assess the effect of pH on the swelling ratio of HA hydrogels for smart drug delivery systems. No beads were formed when the HA solution(below pH 9) was crosslinked with divinyl sulfone(DVS) because DVS is a basic solution. The variation regarding the size of the microbead was not significant, suggesting that the bead size is not a function of pH(10 ~ 14). However, the pore size of the microbeads decreased with increasing pH from 10 to 14, leading to the surface smoothness and dense network as a result of higher crosslinking. The swelling ratio of hydrogels increased when the pH rose from 2(acidic) to 6(neutral). Afterwards, it decreased with further increasing pH(basic). The lower swelling ratio may be due to the lack of ionization of the carboxyl groups. On the other hand, a higher swelling ratio is likely due to the increased electrostatic repulsions between negatively charged carboxyl groups on different chains. Experimental results suggested that pH-responsive HA hydrogels can be applicable to the controlled drug delivery systems.

• 공업화학
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• 제17권4호
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• pp.426-431
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• 2006

Poly(methyl methacrylate) (PMMA)의 착색을 위하여 아크릴 그리고 비닐설폰기를 가지는 청색 및 오렌지 아조 염료들을 6-bromo-2-cyano-4-nitroaniline과 2,5-dimethoxy-4-(vinylsulfonyl)benzenamine을 3-acrylamido-(N,N-diethylamino) benzene과 3-methyl-(N,N-diethylamino)benzene의 아조 짝지음 반응을 이용하여 각각 합성하였다. 또한 알릴기를 가지는 염료는 비닐설폰과 allylamine과의 반응에 의하여 제조하였다. PMMA의 착색은 아크릴, 비닐설폰 그리고 알릴 작용기를 가지는 염료를 직접 methyl methacrylate (MMA)와 공중합하거나, MMA와 공중합한 고분자염료 및 반응성기가 없는 염료 2를 직접 MMA에 용해하여 중합과 동시에 착색하였다. 3가지로 착색한 PMMA의 염색 견뢰도를 여러 환경 조건에서 염료의 용해도를 비교하여 평가하였다.

• 멤브레인
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• 제9권3호
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• pp.170-177
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• 1999

Polysulfone을 술폰화하여 물-부탄올 용액의 분리를 위한 투과증발용 비대칭막을 제조하였다. 술론화제로는 chlorosulfoneic acid-trimethyulchlorosilane을 반응시킨 후 이용하였다. FT-IR과 $^1H$-NMR을 이용하여 치환여부를 살펴보았고 술폰화정도는 역적정법과 $^1H$H-NMR을 이용하여 구하였다. DSC와 TGA를 이용하여 열적특성변화를 알아보았다. 비대칭막을 제조하기 위하여 N-methyl-2-pyrrolidone(NMP)rhkdiethyleneglycol dimethyl ether (DGDE)의 혼합용매를 사용하였다. SEM을 이용하여 단면과 skinlayer 의 구조변화를 살펴보았다. 한 연구에서 제조한 비대칭막은 dense film에 비하여 물에 대한 선택도는 거의 변화가 없고 투과유량은 약 80배 정도 증가하였다.

• 한국가금학회지
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• 제39권4호
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• pp.253-260
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• 2012

This study was undertaken to investigate the influence of multi-probiotics, fermented ginseng byproducts and fermented sulfone as an alternative to probiotics on performance, intestinal microflora and immunity of broiler. A five weeks trial was conducted with one day old Ross${\times}$Ross broilers (n=340), divided into five groups which further divided into 4 replicates with 17 birds in each replicate. Birds were assigned to 5 dietary treatments as control, antibiotic avilamycin (AB), multi-probiotics (MP), fermented sulfone (FS) and fermented ginseng byproducts (FGB). Growth parameters were recorded on weekly basis while rest of the parameters viz. blood and faeces were collected at the end of the experiment. Growth parameters were not affected statistically by dietary treatments. However, numerically, higher body weight, splenocytes proliferation and lower total cholesterol and LDL values were found in MP treatment (P>0.05). Salmonella spp. count ($P{\leq}0.001$) and E. coli (P<0.001) concentrations in the ileum were found lowest in AB treatment while FS group showed lowest level of yeast (P<0.10) and Lactobacillus spp. ($P{\leq}0.001$). Fecal ammonia and $CO_2$ emission was significantly decreased in FGB than other dietary treatments (P<0.05). It was concluded that multi-probiotics would be valuable feed additives to improve the growth performance, Lactobacillus proliferation and immunity of broiler chicks.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1527-1532
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• 2007

Lysine produced during microbial fermentation is usually recovered by an ion-exchange process, in which lysine is first converted to the cationic form (by lowering the pH to less than 2.0 with sulfuric acid) and then fed to a cationexchange column containing an exchanger that has a sulfone group with a weak counterion such as NH;. Ammonia water with a pH above 11 is then supplied to the column to displace the purified lysine from the column and allow its recovery. To enhance the adsorption capacity and for a possible reduction in chemical consumption, monovalent lysine fed at pH 4 was investigated in comparison with conventional divalent lysine fed at pH 1.5. The adsorption capacity increased by more than 70% on a mass basis using pH 4 feeding compared with pH 1.5 feeding. Lysine adsorbed at pH 4 started to elute earlier than that adsorbed at pH 1.5 when ammonia water was used as the eluant solution, and the extent of early elution became more notable at lower concentrations of ammonia. Moreover, the elution of monovalent lysine fed at pH 4 displayed a stiffer front boundary and higher peak concentration. However, when the ammonium concentration was greater than 2.0 N, complete saturation of the bed was delayed during adsorption and the percent recovery yield from elution was lowered., both drawbacks that were considered inevitable features originating from the increased adsorption of monovalent lysine.

• 멤브레인
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• 제19권2호
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• pp.104-112
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• 2009

본 연구에서는 용매로 N-methyl-2-pyrrollidone을 사용하여, 상전환 방법으로 carboxylic acid를 함유한 음이온성 한외여과막을 제조하였다. 첨가제, 제막조건 및 운전조건에 따른 투과 특성을 알아보았다. Bovin serum albumin (BSA) 수용액의 pH에 따른 상대투과유속을 측정하여 fouling형성에 따른 투과 특성의 변화를 살펴보았다. 투과 특성은 막 제조환경과 투과 공정에 영향을 받았다. 이온교환용량과 측정 온도가 증가할수록, 그리고 BSA의 등전점으로부터 수용액의 pH값이 멀어질수록 상대투과유속이 증가하였다.

• 신재생에너지
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• 제2권4호
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• pp.46-55
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• 2006

본 연구는 불소그룹을 함유한 술폰화된 아릴렌에테르계 블록 공중합체 고분자 전해질막의 제조 및 연료전지 특성에 관한 것이다. 이러한 불소그룹을 함유한 술폰화된 아랄렌에테르계 블록 공중합체를 제조하기 위하여 양말단에 불소계 비닐기를 가지면서, 고분자 전환시 상온에서 술폰화 가능한 biphenyl계 단량체와 술폰화가 불가능한 sulfonyl계 단량체를 각각 합성하였다. Biphenyl계 단량체로 부터 올리고머를 합성한 후 sulfonyl계 단량체와 열적 고리화 부가중합을 하여 다양한 몰조성을 갖는 일련의 perfluorocyclobutane(PFCB)기를 포함하는 블록 공중합체를 제조하였다. 제조된 블록 공중합체를 상온에서 술폰화제인 chlorosulfonic acid(CSA)를 이용하여 후술폰화시켜 강산 이온기인 sulfonic acid를 biphenyl계 올리고머 부분에 선택적으로 도입하였다. 이렇게 제조된 술폰화된 고분자를 제막한 후 연료전지 특성을 Nafion-115와 비교하였다. 술폰화가 되는 올리고머 블록의 비율 증가에 따라 이온교환능력 (IEC)이 증가하였고 , 그에 따른 팽윤도 역시 증가하는 것을 보였다. 술폰화된 고분자들은 건조 및 습윤 상태에서도 기계적 강도가 우수하였다. 최적화된 술폰화 블록 고분자(S-2) 를 대상으로 membrane electrolyte assembly(MEA) 를 제조하여 연료전지 초기성능을 측정한 결과 Nafion-112와 유사한 전기화학적 성능을 나타내었다.

• Macromolecular Research
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• 제16권5호
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• pp.457-466
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• 2008

The relation between the phase separated morphologies and their transport properties in the polymer blend membrane for direct methanol fuel cell application was studied. In order to enhance the proton conductivity and reduce the methanol crossover, sulfonated poly(arylene ether sulfone) copolymer, with a sulfonation of 60 mol% (sPAES-60), was blended with nonsulfonated poly(ether sulfone) copolymer (RH-2000, Solvay). Various morphologies were obtained by varying the drying condition and the concentration of the casting solution (10, 15, 20 wt%). The transport properties of proton and methanol molecule through the polymer blend membranes were studied according to the absorbed water. AC impedance spectroscopy was used to measure the proton conductivity and a liquid permeability measuring instrument was designed to measure the methanol permeability. The state of water in the blend membranes was confirmed by differential scanning calorimetry and was used to correlate the morphology of the membrane with the membrane transport properties.