02391nas a2200205 4500008004100000245009400041210006900135260000800204490000600212520167000218653002101888653001301909653002901922653001801951653001701969100002101986700002102007700003002028856012702058 2023 eng d00aCan metal cations electrocatalyze sulfur redox reaction and suppress polysulfide shuttle?0 aCan metal cations electrocatalyze sulfur redox reaction and supp cSEP0 v63 a

In lithium-sulfur (Li-S) batteries, sulfur undergoes various changes. It switches between cyclic structure and linear structure. The charge on the sulfur varies between a neutral state and a negative charge-bearing state. Due to these changes, the sulfur/polysulfide dissolves in the battery electrolyte. Furthermore, the kinetics of the sulfur redox reaction is sluggish. Therefore, a material that can suppress sulfur/polysulfide dissolution and electrocatalyze sulfur redox reaction is needed. We hypothesize that the polysulfide dissolution can be suppressed if the host exhibits polyvalent electrostatic attraction. Polysulfide is a negative charge-bearing molecule; hence the host must comprise multiple positive charges. Nickel cations with other heteroatoms have been explored as a host in Li-S batteries. The heteroatoms impart additional interactions. The easier way to circumvent the effect of heteroatoms is the addition of metal salts. However, metal salts can either exhibit monovalent or divalent attraction with polysulfides. Those interactions are weak and we must have polyvalent interaction. Towards this objective, we have designed and synthesized a material that comprises multiple divalent cations that is also devoid of heteroatoms. The Li-S batteries fabricated using the metal cation immobilized graphene showed a maximum specific capacity of 1022 mAh/g at 0.1 C rate. Among the metal cations, nickel cations showed better performance than cobalt cations. Thus, we demonstrate that metal cations immobilized on Graphene can efficiently electrocatalyze the sluggish sulfur redox reaction and suppress the polysulfide dissolution.

10aelectrocatalysis10agraphene10alithium-sulfur batteries10ametal cations10apolysulfides1 aKumar, Subramani1 aSwain, Gitanjali1 aKrishnamoorthy, Kothandam uhttp://library.ncl.res.in/content/can-metal-cations-electrocatalyze-sulfur-redox-reaction-and-suppress-polysulfide-shuttle02001nas a2200217 4500008004100000022001400041245008700055210006900142260000900211300001500220490000600235520129500241653001401536653001901550653001801569653001801587653001601605100002301621700002101644856011801665 2023 eng d a2365-654900ai-Indigo-based self-assembled microparticles and their conversion to nanoparticles0 aiIndigobased selfassembled microparticles and their conversion t cAUG  ae2023008590 v83 a

Microscopic particles (MPs) are used to scatter and reflect UV light. It is well established that inorganic MPs such as TiO2 and ZnO produce carcinogens. Therefore, organic MPs are explored for UV absorption. Conjugated chromophores with differing lipophilicity usually self-assemble into nanoscopic structures. In our previous experiments, unsymmetrical i-Indigo was found to self-assemble into 500 nm particles. We hypothesized that the size of the self-assembled particles can be increased by increasing the lipophilicity difference between the side chains. Toward this objective, we have chosen the i-Indigo core with TEG and alkyl chains as side chains. As a result, the i-Indigo molecules were found to self-assemble into 3 & mu; spheres in solution. By substituting side chains with different lipophilicity, i-Indigo microparticles with the size of 5 & mu; are prepared. A careful analysis showed that the spheres are similar to a soccer ball, and they deflate upon drying on the substrate surface. The judiciously chosen side chain binds with a metal-ion (Cs+) and forms nanoscopic assemblies. After Cs+ binding, the size of the particles is decreased drastically to 100 nm. The simple addition of ions converts microscopic assemblies into nanoscopic assemblies.

10aIsoindigo10amicroparticles10aNanoparticles10aSelf-assembly10aUV absorber1 aSingh, Anup, Kumar1 aSwain, Gitanjali uhttp://library.ncl.res.in/content/i-indigo-based-self-assembled-microparticles-and-their-conversion-nanoparticles02297nas a2200241 4500008004100000245013900041210006900180260000800249300001400257490000600271520142600277653002201703653001101725653002801736653001501764653002501779653002001804100002101824700003401845700002301879700003001902856012301932 2023 eng d00aOrganic field effect transistors comprising copolymers synthesized without structure-directing moieties with enhanced carrier mobility0 aOrganic field effect transistors comprising copolymers synthesiz cAPR a2338-23440 v53 a

Conjugated materials are synthesized by C-C bond formation reactions. Trimethyltin and boronic acid are two widely used structure-directing moieties. While using the ethynyl moiety as a part of the monomer, additional structure-directing moieties are not needed. However, ethynylene will be part of the conjugated material. Often, the polymers with an ethynylene moiety negatively impact the polymers' properties. However, the ethynylene moiety could minimize the dihedral angle if the monomer has steric functionalities. For example, BODIPY is an attractive monomer due to its high molar extinction coefficient, partial quinoidal character, and high quantum yield. However, materials based on BODIPY exhibited poor charge carrier mobility due to steric hindrance generated by four methyl groups. Herein, we copolymerize BODIPY with ethynylene comprising i-indigo and thieno-i-indigo. The copolymer with thieno-i-indigo showed increased molecular weight and significantly reduced band gap compared to the copolymer with i-indigo. The copolymer with i-indigo showed immeasurably low hole transport mobility. On the other hand, the copolymer with thieno-i-indigo exhibited 0.003 cm2V(-1) s(-1). These measurements were made using field effect transistors. We also measured the charge carrier mobility using the space charge-limited current method. Both copolymers exhibited a mobility of 10(-3) cm(2) V-1 s(-1).

10aacetylene linkage10aBODIPY10afield effect transistor10aiso-indigo10aSonogashira coupling10athienoisoindigo1 aSwain, Gitanjali1 aJavaregowda, Bharathkumar, H.1 aDambhare, Neha, V.1 aKrishnamoorthy, Kothandam uhttp://library.ncl.res.in/content/organic-field-effect-transistors-comprising-copolymers-synthesized-without-structure