Archita Patnaik

The formation of self-assembled chemisorbed monolayers (SAM) of 8-amino-1-undecane thiol functionalized with fullerene C60 on gold, has been studied by contact angle measurements, Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). A two-step procedure was followed consisting of the chemisorption of amine-terminated organosulfur compounds, followed by their reaction with fullerenes at the solid-liquid interface. Covalent binding of fullerenes to these attachment layers was accessed by FTIR-ATR and XPS. ATR showed several major features in the C60 skeleton ring vibration region along with all the characteristic features of the aminothiol. With increase in carbon to sulfur ratio, appearance of a C1s shake-up satellite peak due to the characteristic π-π* transition of the C60 backbone and a low binding energy N1s feature confirmed the -NH2 binding at the 6,6 double bond of the C60 cage. Possible explanations for these experimental findings are discussed. © 2003 Elsevier Inc. All rights reserved.

Structural and chemical investigation for the laser ablated Poly (Phenylene Sulfide) (PPS) films upon 100 keV H+ implantation is reported here for the first time. PPS thin films were fabricated by laser ablation with a Nd: YAG laser as a source of visible photons (532 nm). The laser ablated thin films showed strong polymer breakdown resistance upto a total fluence of 1015 ions/cm2. Bulk properties of the as-deposited and the implanted samples were investigated using FTIR and UV-VIS spectroscopy. Drastic reduction in the intensity of all characteristic vibrational frequencies in the FTIR spectrum at higher doses revealed the transformation of the polymer to a conjugated carbonaceous material. UV-VIS studies showed a positive shift in the absorption edge value for the as-deposited polymer towards higher wavelengths and destruction of phenyl ring due to the H+ bombardment. X-ray Photoelectron Spectroscopic (XPS) investigation indicated the sulfur depletion as a prominent phenomenon whereas carbon content remained almost the same. XPS studies of the implanted sample also revealed a minor change in the oxidized species of carbon and more prominent change in oxidized species of sulfur which were present in the as-deposited samples. A peak at 283.4 eV attributed to 'surface reconstruction' in the XPS analysis for the as-deposited PPS film disappeared after proton implantation. © 1998 Elsevier Science B.V.

The structure of the C 60 -fullerene terminated aminothiol self-assembled monolayers (SAM) generated by tethering the fullerene molecules to the surface of 11-amino-1-undecane thiol (11-AUT) SAM on gold surface was investigated by dynamic contact angle measurements, Fourier transform infrared reflection-absorption spectroscopy (FTIR-RAS), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). A two-step procedure was followed consisting of the chemisorption of the amine-terminated organosulfur compound on oriented gold, followed by its reaction at the solid liquid interface with C 60 fullerenes. Covalent binding of fullerenes to these attachment layers was accessed by the above experimental techniques. IR-RAS showed several major features in the C 60 skeleton ring vibration region along with all the characteristic features of the amino thiol. With increase in carbon to sulfur ratio, appearance of C 1s shake-up satellite peak due to characteristic π-π * transition of the C 60 backbone confirmed the NH 2 binding at the 6,6 double bond of the C 60 cage. Atomic force microscopy showed smooth, homogeneous areas of the monomolecular films, covered by regular small microcrystalline grains on the fullerene-terminated monolayer surface. Possible explanations for these experimental findings are discussed. © 2004 Elsevier B.V. All rights reserved.