01836nas a2200181   4500008004100000022001400041245006900055210006900124260011000193300001400303490000700317520112700324100002601451700002501477700002001502700003001522856010201552       2012                        eng d  a1463-907600aBand edge modulated conjugated polymers for oxidation prevention0 aBand edge modulated conjugated polymers for oxidation prevention  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a4577-45830 v143 a<p>The impact of electron transfer (ET) from a series of band edge modulated polymers to atmospheric oxygen is examined in connection with substrate oxidation prevention. Polymers with the highest occupied molecular orbital (HOMO) energy level below and above the oxygen energy level were tested and the former showed better efficiency. Furthermore, the oxidation prevention efficiency of a polymer with lower HOMO increased by two orders of magnitude, when the pores on the film were filled with spherical molecules, [6,6]-phenyl-C61-butyric acid methyl ester. We found that the polymer surface hydrophobicity has little or no influence on oxidation prevention. It is interesting to note that a polymer with a hole mobility of 8 x 10(-10) cm(2) V-1 s(-1) showed a two-fold increase in oxidation prevention efficiency compared to a polymer with a hole mobility of 6 x 10(-5) cm(2) V-1 s(-1). Over all, from the concerted approach, we conclude that a polymer devoid of pores with the HOMO energy level below oxygen and low charge carrier mobility is a suitable candidate for prevention of substrate oxidation/corrosion.</p>1 aMahale, Rajashree, Y.1 aArulkashmir, Arulraj1 aDutta, Kingshuk1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/band-edge-modulated-conjugated-polymers-oxidation-prevention-001612nas a2200169   4500008004100000245012300041210006900164260000800233300001600241490000700257520095300264100002001217700002601237700002501263700003001288856012401318       2012                        eng d00aReversible assembly and disassembly of micelles by a polymer that switches betweenhydrophilic and hydrophobic wettings0 aReversible assembly and disassembly of micelles by a polymer tha  cJUN  a10097-101040 v283 aSupramolecular complexes involving nanoscopic amphiphilic assemblies (AAs) and polyelectrolytes have been used to prepare a variety of materials, wherein the dynamic AAs retain the structural features, but the polyelectrolytes undergo conformational changes. Here we show that a charge bearing rigid conjugated polymer can alter the structural features and disassemble AAs. We also demonstrate reversible assembly and disassembly of AAs by controlling the number of charges on the rigid polymer. During the disassembly, the guest molecules sequestered in the AAs are released. The rate of release has been modulated by changing the morphology of the charge bearing polymer. Concomitant to the AAs disassembly, the polymer surface becomes hydrophobic due to the binding of the amphiphiles on the charges of the polymer backbone. By controlling the charges on the polymer, the surface wettability was varied gradually from hydrophilic to hydrophobic.1 aDutta, Kingshuk1 aMahale, Rajashree, Y.1 aArulkashmir, Arulraj1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/reversible-assembly-and-disassembly-micelles-polymer-switches-betweenhydrophilic-and02097nas a2200181   4500008004100000245010100041210006900142260000800211300001400219490000600233520141200239100002501651700002601676700002901702700002201731700003001753856013201783       2012                        eng d00aSupramolecular interaction facilitated small molecule films for organic field effect transistors0 aSupramolecular interaction facilitated small molecule films for   cAPR  a1641-16460 v33 aMetalloporphyrins and metal free porphyrins have been explored as active materials in field effect transistors. Amorphous forms of these porphyrins are preferred over their crystalline analogue due to the ease of solution processability. To achieve solution processability, a metalloporphyrin was anchored on a vinyl polymer by taking advantage of the supramolecular interaction between the metal and the pyridine moiety of the polymer. Non covalent bonding was preferred because it provides an opportunity to better manipulate the polymer's properties compared to its covalent bonding analogue. The binding between the porphyrin and the polymer was optimised in solution and the supramolecular complex was spun on various substrates to form thin films. The porphyrin was found to be uniformly distributed throughout the polymer films contrary to the existing approaches, wherein small molecule phase segregates in the polymer film. Field effect transistors were fabricated using the porphyrin-polymer complex and the device parameters were measured at atmospheric condition. The devices annealed at 80 degrees C showed hole carrier mobility of 2.0 x 10(-4) cm(2) V-1 s(-1) with charge trapping at the dielectric semiconductor interface. Furthermore, the high carrier mobility observed at low temperature annealing makes this supramolecular complex an attractive candidate to explore in flexible substrates.1 aArulkashmir, Arulraj1 aMahale, Rajashree, Y.1 aDharmapurikar, Satej, S.1 aJangid, Manoj, K.1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/supramolecular-interaction-facilitated-small-molecule-films-organic-field-effect-transistors02169nas a2200157   4500008004100000245009300041210006900134260000800203300001600211490000600227520157400233100002501807700002301832700003001855856012601885       2013                        eng d00aCleavable and removable polymer thermosets for organic field effect transistor packaging0 aCleavable and removable polymer thermosets for organic field eff  cSEP  a22591-225960 v33 aRecent years have witnessed tremendous progress in the design and synthesis of electroactive materials for the fabrication of organic electronic devices. However, very little research effort has been devoted to developing organic packaging materials, which are crucial for the efficient functioning of the devices. Polymer thermosets (PTs) are extensively used for the packaging of microelectronic and optoelectronic devices. Although PTs are effective in providing mechanical stability and environmental protection to devices, the removal of PTs without destroying the underlying surface is cumbersome. Facile removal of PTs is essential to reuse the expensive substrates. Herein, we report the preparation of a thermoset using an aliphatic disulfide containing cross-linker, cystamine. By varying the cross-linker concentration, the mechanical property of the thermoset was varied from ductile to brittle. The ductile thermoset was coated on metal, semiconductor and flexible substrates. The thermosets were then cleaved using a biomolecule in neutral pH. We have demonstrated that the cleavage and removal of thermosets don't affect the surface properties of the underlying substrates. Furthermore, the thermosets were coated on top of organic field effect transistors to provide environmental protection. The thermoset coated devices showed a charge carrier mobility of 5.3 x 10(-3) cm(2) V-1 s(-1). Then, the thermoset was cleaved and removed, and the substrate was reused for the fabrication of organic field effect transistors with unchanged device efficiencies.1 aArulkashmir, Arulraj1 aBhosale, Manik, E.1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/cleavable-and-removable-polymer-thermosets-organic-field-effect-transistor-packaging-002439nas a2200265   4500008004100000022001400041245012600055210006900181260007100250300001400321490000600335520144400341653001801785653001301803653003601816653002701852653002001879653001901899100002901918700002501947700001901972700002001991700003002011856013202041       2013                        eng d  a1944-824400aEnhanced hole carrier transport due to increased intermolecular contacts in small molecule based field effect transistors0 aEnhanced hole carrier transport due to increased intermolecular   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG  a7086-70930 v53 a<p>Small molecules and oligomers can be synthesized with very high purity and precise molecular weights, but they often do not form uniform thin films while processed from solution. Decreased intermolecular contacts between the small molecules are another disadvantage. To increase the intermolecular contacts in small molecules, we have chosen i-indigo, as one of the conjugated molecular units. The electron poor i-indigo has been connected with electron rich triphenylamine to synthesize a donor-acceptor-donor type small molecule. The propeller shaped triphenylamine helps to increase the solubility of the small molecule as well as isotropic charge transport. The intermolecular spacing between the molecules has been found to be low and did not vary as a function of thermal annealing. This implies that the intermolecular contacts between the small molecules are enhanced, and they do not vary as a function of thermal annealing. Organic field effect transistors (OFET) fabricated using a small molecule exhibited a hole carrier mobility (mu) of 0.3 cm(2)/(V s) before thermal annealing. A marginal increase in mu was observed upon thermal annealing at 150 degrees C, which has been attributed to changes in thin film morphology. The morphology of the thin films plays an important role in charge transport in addition to the intermolecular spacing that can be modulated with a judicious choice of the conjugated molecular unit.</p>10ahole mobility10ai-indigo10aorganic field effect transistor10aquadrupole interaction10asmall molecules10atriphenylamine1 aDharmapurikar, Satej, S.1 aArulkashmir, Arulraj1 aDas, Chayanika1 aMuddellu, Pooja1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/enhanced-hole-carrier-transport-due-increased-intermolecular-contacts-small-molecule-based-001035nas a2200193   4500008004100000022001400041245013700055210006900192260011000261300001200371490000700383520021200390100002500602700002200627700001900649700001500668700003000683856012800713       2014                        eng d  a1359-734500aChemically doped perylene diimide lamellae based field effect transistor with low operating voltage and high charge carrier mobility0 aChemically doped perylene diimide lamellae based field effect tr  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT  a326-3280 v503 a<p>Chemical doping of an electron transporter results in the formation of a radical anion containing semiconductor which showed high electron mobility (13 cm(2) V-1 s(-1)) at low operating voltage (1 V).</p>1 aArulkashmir, Arulraj1 aJain, Bhanprakash1 aJohn, Jino, C.1 aRoy, Kanak1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/chemically-doped-perylene-diimide-lamellae-based-field-effect-transistor-low-operating-001631nas a2200193   4500008004100000022001400041245009900055210006900154260007100223300001400294490000700308520087000315100002001185700002501205700003001230700002301260700003001283856012401313       2014                        eng d  a1528-748300apH-Dependent single-step rapid synthesis of cuo and cu2o nanoparticles from the same precursor0 apHDependent singlestep rapid synthesis of cuo and cu2o nanoparti  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a4329-43340 v143 a<p>A single-step protocol to prepare Cu2O and CuO nanocrystalline particles from the same precursor by microwave irradiation has been developed using the pH of the solution as the only variable parameter. The utility of different bivalent Cu-precursors for synthesis of CuO and Cu2O nanoparticles was also investigated. The morphology, phase purity, and optical properties of these nanoparticles were analyzed using TEM, SEM, XRD, and optical spectroscopy. The band edges were determined using cyclic voltammetry. Field effect transistors based on CuO nanoparticles showed a hole mobility of 3.5 x 10(-2) cm(2) V-1 s(-1), making them a suitable candidate for energy-related applications. The effect of hydrazine vapor exposure on the IV-characteristics of CuO nanoparticles was also investigated. This revealed a decrease in source current with respect to time.</p>1 aNikam, Arun, V.1 aArulkashmir, Arulraj1 aKrishnamoorthy, Kothandam1 aKulkarni, Amol, A.1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/ph-dependent-single-step-rapid-synthesis-cuo-and-cu2o-nanoparticles-same-precursor-001905nas a2200169   4500008004100000022001400041245012300055210006900178260007500247300001200322490000600334520118700340100002501527700002401552700003001576856012901606       2016                        eng d  a1614-683200aBand edge modulated polymer layer to decrease back electron transfer and increase efficiency in sensitized solar cells0 aBand edge modulated polymer layer to decrease back electron tran  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcMAY  a15023340 v63 a<p>Recombination of charges residing in the TiO2 and redox electrolyte is one of the factors affecting the efficiency of dye sensitized solar cells (DSSCs). To circumvent this recombination, inorganic oxide barrier layers and organic silanes have been coated on TiO2/dyes. Due to the insulating nature of these layers, the efficiency increase is not very impressive. Conducting polymers with different band edges are used to suppress the charge recombination. Amongst the four polymers that are used as barrier layers, a polymer with a highest occupied molecular orbital energy at -5.8 eV and lowest unoccupied molecular orbital at -3.1 eV is found to increase the electron life time at TiO2 and decrease the charge recombination. The electron life time is found to be 88 ms. In addition to the long electron life time, the recombination resistance of this polymer is also high (91 Omega). This resistance is 18% higher than that measured for DSSCs without polymer barrier layer. These factors impact the efficiency of DSSCs. DSSCs fabricated with this polymer as barrier layer exhibit an efficiency of 9.2%, which is 22% higher than that of DSSCs without polymer barrier layer.</p>1 aArulkashmir, Arulraj1 aSudhakar, Vediappan1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/band-edge-modulated-polymer-layer-decrease-back-electron-transfer-and-increase-efficiency01699nas a2200253   4500008004100000245009000041210006900131260000800200300001000208490000800218520083300226100002801059700003001087700002501117700002001142700002001162700003001182700001601212700003701228700001801265700002401283700002101307856011701328       2016                        eng d00a"Click" polymerization: a convenient strategy to prepare designer fullerene materials0 aClick polymerization a convenient strategy to prepare designer f  cOCT  a34-410 v1083 a"Click" polymeric assemblies of fullerenes, thiophenes and aryl compounds were prepared for the first time to study their spectroscopic/chemical/electronic characteristics and possible applications in photovoltaic cells. The GPC and NMR spectroscopic data confirmed a moderate to high degree of polymerization while microscopic pictures showed well-defined arrangements of fullerenes. The FTIR studies indicated that the product is free from starting azide materials, whereas thermogravimetric analysis data suggested a good stability. Band gap of the material was determined using UV-Vis spectroscopy, cyclic voltammetric techniques and compared with computational investigation. The fullerene copolymer was fabricated as acceptor material in a bulk heterojunction photovoltaic cell. (C) 2016 Elsevier Ltd. All rights reserved.1 aKrishnamurthy, Munusamy1 aKrishnamoorthy, Kothandam1 aArulkashmir, Arulraj1 aRaghavendra, V.1 aMurali, Adhigan1 aJaisankar, Sellamuthu, N.1 aMurugan, P.1 aGurusamy-Thangavelu, Senthil, A.1 aNasar, Sultan1 aMandal, Asit, Baran1 aSamanta, Debasis  uhttps://library.ncl.res.in/content/click-polymerization-convenient-strategy-prepare-designer-fullerene-materials00987nas a2200157   4500008004100000022001400041245010800055210006900163260011000232300001400342490000700356520028600363100002500649700003000674856012500704       2016                        eng d  a1359-734500aDisassembly of micelles to impart donor and acceptor gradation to enhance organic solar cell efficiency0 aDisassembly of micelles to impart donor and acceptor gradation t  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a3486-34890 v523 a<p>A transparent, conducting and low surface energy surface was prepared by disassembly of anionic micelles, which altered the orientation of the donor polymer and imparted gradation between the donor and acceptor. This configuration increased the solar cell device efficiency.</p>1 aArulkashmir, Arulraj1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/disassembly-micelles-impart-donor-and-acceptor-gradation-enhance-organic-solar-cell-000860nas a2200157   4500008004100000245012600041210006900167260000800236300001400244490000700258520022600265100002400491700002500515700003000540856013200570       2017                        eng d00aPolymer and graphene layer to increase dye regeneration and suppress back electron transfer in dye sensitized solar cells0 aPolymer and graphene layer to increase dye regeneration and supp  cJUN  a6629-66320 v533 aDye regeneration was improved by using an optimum quantity of graphene, which was dispersed in a polymer that suppresses back electron transfer. Using this approach, DSSCs with an efficiency of 10.4% have been fabricated.1 aSudhakar, Vediappan1 aArulkashmir, Arulraj1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/polymer-and-graphene-layer-increase-dye-regeneration-and-suppress-back-electron-transfer-dye02034nas a2200289   4500008004100000022001400041245010900055210006900164260000800233490000800241520101300249653001001262653008901272653002401361653002101385653001301406653001401419653001901433653001601452653001601468653002601484100002901510700002501539700002601564700002601590856012801616       2017                        eng d  a0021-899500aSynthesis of amphiphilic isoindigo co-polymers for organic field effect transistors: A comparative study0 aSynthesis of amphiphilic isoindigo copolymers for organic field   cNOV0 v1343 a<p><span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; background-color: rgb(248, 248, 248);">In this work, the amphiphilic isoindigo (am-iInd) based conjugated polymers namely poly(am-iInd-DT) and poly(am-iInd-TT) and their regular counterpart poly(reg-iInd-DT) and poly(reg-iInd-TT) were synthesized to compare their opto-electronic and charge transport properties. They were used to fabricate organic field effect transistors. Charge transport properties in conjugated polymers depend upon intermolecular interaction which is strongly affected by the nature of side chains. The amphiphilic nature of the conjugated polymers has little impact on the charge transport properties. The charge carrier mobility of amphiphilic conjugated polymers was comparable with the regular polymers except poly(reg-iInd-DT) which can be correlated by X-ray diffraction and thin film morphology. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45461.</span></p>10aAlkyl10aApplications; Conducting polymers; Copolymers; Optical and Photovoltaic applications10aconjugated polymers10aHigh-performance10amobility10aPackaging10aSemicondoctors10aSide-chains10aSolar-cells10aThin-film Transformer1 aDharmapurikar, Satej, S.1 aArulkashmir, Arulraj1 aMahale, Rajashree, Y.1 aChini, Mrinmoy, Kumar  uhttps://library.ncl.res.in/content/synthesis-amphiphilic-isoindigo-co-polymers-organic-field-effect-transistors-comparative