GOUTAM DE
Articles written in Journal of Chemical Sciences
Volume 120 Issue 6 November 2008 pp 565-572
Samar Kumar Medda Moumita Mitra Goutam De
Inorganic (silica-titania)-organic (polyethylene oxide) hybrid films with variable refractive index (RI) values were synthesized and Ag nanoparticles were generated
Volume 128 Issue 9 September 2016 pp 1345-1354 Regular Article
KOUSHIK BHOWMIK AMRITA CHAKRAVARTY U MANJU GOUTAM DE ARNAB MUKHERJEE
Graphite nanosheets are considered as a promising material for a range of applications from flexible electronics to functional nanodevices such as biosensors, intelligent coatings and drug delivery. Chemical functionalizationof graphite nanosheets with organic/inorganic materials offers an alternative approach to control the electronic properties of graphene, which is a zero band gap semiconductor in pristine form. In this paper, we report the aromatic electrophilic substitution of solution exfoliated graphite nanosheets (SEGn). The highly conjugated π-electronic system of graphite nanosheets enable it to have an amphiphilic characteristic in aromatic substitution reactions. The substitution was achieved through Friedel–Crafts (FC) acylation reaction under mild conditions using succinic anhydride as acylating agent and anhydrous aluminum chloride as Lewisacid. Such reaction renders towards the carboxylic acid terminated graphite nanosheets (SEGn–FC) that usually requires harsh reaction conditions. The product thus obtained was characterized using various spectroscopicand microscopic techniques. Highly stable water-dispersed sodium salt of carboxylic acid terminated graphite nanosheets (SEGn–FC-Na) was also prepared. A comparative sheet-resistance measurements of SEGn, SEGn–FC and SEGn–FC-Na were also done. Finally, the anticancer drug doxorubicin (DOX) was loaded on water dispersible SEGn–FC-Na with a loading capacity of 0.266 mg mg−1 of SEGn–FC-Na and the release of DOX from this water-soluble DOX-loaded SEGn–FC-Na at two different temperatures was found to be strongly pHdependent.
Volume 130 Issue 8 August 2018 Article ID 0109
TANUMOY DHAWA SHREYASI CHATTOPADHYAY MONJOY SREEMANY GOUTAM DE SOURINDRA MAHANTY
Effective trapping of polysulfides within the carbon cathode host strongly depends on intrinsic C–S interactions. We report herein a systematic study of the influence of S-loading process on C–S interactions in MWCNT/S composites prepared by three commonly used industry-friendly methods, namely, mechanical solidstate mixing, infiltration method from a solution of S in CS2, and chemical deposition by disproportionation reaction of sodium sulfide and sodium thiosulfate. FESEM and TEM studies reveal strikingly different morphologies of the resulting MWCNT/S composites. XPS and Raman studies indicate different extents of recovery of π bonds in MWCNT due to varying degrees of C–S interfacial interactions in the composites. Furthermore, it is found that the C/O atomic ratio in the composites plays a crucial role: the higher the C/O valuethe better is the S-confinement. These subtle physical changes induced by C–S interactions in the composites can be related to electrochemical performance when tested in Li-S coin cells. It is found that the best results (high initial capacity of 1143 mAh g -1 and better capacity retention) could be achieved when the solution infiltration method was used for S-loading. This conclusion is further validated by using activated carbon as S-host.
Volume 135, 2023
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