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Sabuj Chandra Sutradhar,Md Mahabubur Rahman,Faiz Ahmed,류태욱,윤수진,이승찬,김재웅,이용훈,Yongcheng Jin,김환기 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.76 No.-
Thermally and chemically stable sulfonated poly(phenylenebenzophenone)s (SPPBP) membranes havebeen synthesized from 1,4-dichloro-2,5-diphenylene methoxy benzophenone (PMBP) and 1,4-dichloro-2,5-dibenzoyl benzene (PBP) monomers by using Ni (0) catalyst for proton exchange membrane fuel cells(PEMFC). The synthesized SPPBP membranes exhibited ion exchange capacity from 1.18 to 2.30 meq/g.,water uptake from 34.2 to 78.3% and proton conductivity from 36.94 to 92.90 mS/cm. Additionally, the C–C coupling polymerization improved the thermal and chemical stability of the SPPBP membranes. Furthermore, the pendent benzophenone acid moiety provided the well hydrophilic/hydrophobic phaseseparation morphology with increased conductivity. Therefore, the SPPBP membranes can be a potentialcandidate for proton exchange membrane fuel cell (PEMFC).
A Novel Method for Optimizing Power Efficiency of a Solar Photovoltaic Device
Sabuj Sarkar,Md. Mostafi zur Rahman 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.4
Most recently, photovoltaic energy has made an incredible technological advancement for the forthcoming decades towards mitigating the ever-increasing energy demand worldwide through generating electric power. Present paper proposes a novel solar photovoltaic (SPV) device model that achieves optimal power effi ciency from simulation and graphical performance analysis of SPV device characteristics. First of all, power as well as current performances is compared for varying irradiance and temperatures circumstances. Then, output current characteristics of the SPV device for the proposed as well as existing model with variable temperatures is plotted. Later, power versus voltage performances of a SPV device for the proposed model with varying irradiance and temperature criterions is compared. Finally, power–voltage characteristics are plotted graphically for the existing as well as proposed SPV device model that achieves signifi cant amount of output power for the proposed model than the existing model and optimal power effi ciency is obtained for the novel SPV device model.
Synthesis and characterization of sulfonated mutiphenyl conjugated polyimide for PEMFC
류태욱,Sabuj Chandra Sutradhar,Faiz Ahmed,최건영,양한모,윤수진,이성권,김환기 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.49 No.-
A new monomer, di-sulfuricacid-1,1-bis(4-aminophenyl)-2,2-diphenylethylene (SBAPDPE), was synthesizedby direct sulfonation of the parent diamine, 1,1-bis(4-aminophenyl)-2,2-diphenylethylene(BAPDPE) using concentrated sulfuric acid. A series of the side-chain-type sulfonated conjugatedtetraphenylethylene polyimides (SCTPPIs) with different degrees of sulfonation were prepared fromdianhydrides with SBAPDPE and non-sulfonated diamine. The SCTPPIs generally showed good solubilityin m-cresol and DMSO. The membranes were studied by FT-IR, 1H NMR spectroscopy, and TGA. Sorptionexperiments were conducted to observe the interaction of sulfonated polymers with water. The ionexchange capacity (IEC) and proton conductivity were evaluated with increase of degree of sulfonation
Santosh Kumar,Sabuj Mallik,Ndy Ekere,정재필 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.5
Stencil printing for flip chip packaging using fine particle solder pastes is a low cost assembly solution with high throughput for fine pitch solder joint interconnects. The manufacturing challenges associated with both solder paste printing increases as electronic device size decreases due to trend of miniaturization in electronic components. Among multiple parameters, the two most important stencil printing parameters are squeegee pressure and printing speed. In this paper, the printing behavior of Pb free Sn-3Ag-0.5Cu solder paste with a particle size distribution of 2-12 μm for wafer level bumping using a stencil printing method (stencil opening dimension -30 μm) was evaluated by varying the printing speed and squeegee pressure to fabricate solder bumps with a sub 100 μm size. The optimal squeegee pressure and print speed for the defect free printing behavior and fairly uniform size distribution of reflowed paste were found to be 7 kgf and 20 mm/s,respectively. The average size of the reflowed printed paste decreased with the increasing squeegee pressure.
Synthesis and characterization of fluorosulfonyl imide isatin biphenylene block copolymer for PEMFC
Ryu, Taewook,Chandra, Sabuj Sutradhar,Ahmed, Faiz,Lopa, Nasrin Siraj,Yoon, Soojin,Yang, Hanmo,Lee, Seungchan,Choi, Inhwan,Kim, Whangi Elsevier 2018 International journal of hydrogen energy Vol.43 No.26
<P><B>Abstract</B></P> <P>In this study, A fluorosulfonyl imide-containing precursor derived from fluorosulfonyl isocyanate was synthesized and grafted on poly (isatin-biphenylene) random and block copolymers. The carbon-carbon structured poly (isatin biphenylene)s were prepared by super acid catalyzed polyhydroxyalkylation reaction with istain, 2,2′-biphenyl, 2,2′-dihydroxybiphenyl. A fluorosulfonyl imide-containing precursor was prepared from chlorosulfuric acid and fluorosulfonylisocyanate. Fluorosulfonyl imide group have higher acidity than sulfonic acid group, therefore the membranes containing fluorosulfonyl imide groups instead of sulfonic acid groups were studied. These membranes showed slightly higher performance of proton conductivity, low water uptake, and good dimensional stability. The structure of the synthesized polymer was investigated by <SUP>1</SUP>H NMR spectroscopy. Surface morphologies will also be assessed by atomic force microscope (AFM). Microphase-separated block copolymers are preferred over random copolymers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Block and random copolymers were synthesized from biphenyl, 2,2′-biphenol and isatin via super acid catalyzed. </LI> <LI> Fluorosulfonyl imide super strong acid was grafted on copolymers instead of sulfonic acid. </LI> <LI> Block copolymer showed better proton conductivity, physical, and chemical stability than random copolymer. </LI> <LI> Block copolymer showed the IEC and water uptake value 1.45 meq./g and 19.14% respectively. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Random and block copolymers successfully synthesized from isatin, biphenyl and 2.2′-biphenol with super acid catalyst. Block copolymer membranes show higher proton conductivity than random copolymers. The block copolymer showed the IEC value 1.45 meq./g, water uptake 19.14% and the proton conductivity 78.89 mS/cm at 80 °C under 90% RH. Block copolymer membrane showed a greater dependence of proton conductivity on the relative humidity, and had higher conductivity and cell performance than that of random copolymer with similar IEC value. These results showed that the morphology of polymer matrix greatly affected the cell performance and membrane with well-separated hydrophilic/hydrophobic phase is very important in the fuel cell application. This research demonstrated the possibility of promising BPIIB membranes for excellent proton conductivity and cell performance.</P> <P>[DISPLAY OMISSION]</P>
Ahmed, Faiz,Sutradhar, Sabuj Chandra,Ryu, Taewook,Jang, Hohyoun,Choi, Kunyoung,Yang, Hanmo,Yoon, Sujin,Rahman, Md. Mahbubur,Kim, Whangi Pergamon Press 2018 International journal of hydrogen energy Vol.43 No.10
<P><B>Abstract</B></P> <P>Branched and linear sulfonated poly(phenylene)s (BSPs and LSPs, respectively) polymer electrolyte membranes (PEMs) containing benzophenone moiety were successfully synthesized and the performance of the LSPs and BSPs were compared in conjunction with Nafion 211<SUP>®</SUP>. The LSPs and BSPs were synthesized by the CC coupling polymerization reaction between 1,4-dichloro-2,5-dibenzoylbenzene (PBP) and 1,4-dichloro-2-benzoylbenzene, and from PBP, 1,4-dichloro-2-benzoylbenzene, and 1,3,5-trichlorobenzene (branching agent), respectively. The degree of sulfonation in both LSPs and BSPs were controlled by varying the concentrations of chlorosulfonic acid and the structures of the resultant PEMs were confirmed by <SUP>1</SUP>H-NMR spectroscopy. The optimal LSP (LSP-2) and BSP (BSP-2) PEMs showed excellent chemical stability due to the absence of ether linkages in the polymer backbone, while the BSP-2 exhibited better proton conductivity (94.6 mS/cm under 90% relative humidity at 80 °C), water resistivity, and lower dimensional changes compared to the LSP-2, which is comparable to Nafion 211<SUP>®</SUP>. The maximum power density for BSP-2 and LSP-2 were 0.60 and 0.49 W/cm<SUP>2</SUP>, respectively, while it was 0.62 W/cm<SUP>2</SUP> for Nafion 211<SUP>®</SUP>. Membrane properties were studied with regard to ion exchange capacity, dimensional stability, proton conductivity, thermogravimetric analysis, and water uptake. The surface morphology of membranes was also analyzed by atomic force microscope.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Branched and linear sulfonated (BSP and LSP, respectively) polymer electrolyte membranes (PEMs) were synthesized. </LI> <LI> The properties and the performance of the synthesized PEMs were compared in conjunction with Nafion 211<SUP>®</SUP>. </LI> <LI> The optimal BSP showed better proton conductivity, physical, and chemical stability than LSPs. </LI> <LI> The power density in fuel cells based on optimized BSP, LSP, and Nafion 211<SUP>®</SUP> were 0.60, 0.49 and 0.62 W/cm<SUP>2</SUP>, respectively. </LI> </UL> </P>
Preparation and Characterization of Anti-Scratch Polycarbonate Containing Acrylate Group
Jang, Hohyoun,Sutradhar, Sabuj Chandra,Ryu, Taewook,Choi, Kunyoung,Yoon, Sujin,Lee, Sungkwun,Kim, Whangi American Scientific Publishers 2017 Journal of nanoscience and nanotechnology Vol.17 No.10
<P>Polycarbonate copolymers containing valeric ester were synthesized from bisphenol A and valeric acid as the comonomer by the interfacial polymerization. The oligomer was synthesized from an aqueous bisphenol A and valeric acid in sodium hydroxide solution with solution of tetra butyl ammonium chloride (TBAC) in water (85%) as the phase transfer catalyst (PTC) and triphosgene in methylene chloride, followed by further reaction with triethylamine (TEA) to increase the molecular weight. The valeric acid groups were converted into the acrylate form by substitution reaction with iodomethane. The chemical structure and thermal properties of copolycarbonates were measured by H-1-NMR, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Moreover, the surface morphologies were assessed by atomic force microscopy (AFM), and the contact angle measurement of a sessile water drop onto the polymer firms was also performed. The hardness increased from 6B for linear polycarbonate to 45B grades of the copolymer films (100 mu m).</P>