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Crystalline fullerene C70 microtubes (FMTs) were produced employing ultrasound-assisted liquid– liquid interfacial precipitation (ULLIP) technique at the interface between fullerene C70 solution in 1,2 dichlorobenzene (DCB) and isopropanol (IPA) at 15 °C. Using the vortex-flow motion of the subphase water (also called Vortex-Langmuir-Blodgett technique), the FMTs were aligned and homogeneous films were prepared at the air-water interface. The aligned FMTs film exhibited enhanced photoluminescence (PL) with PL intensity ~5 times higher than that of the pristine C70. Moreover, the aligned FMT film showed better photovoltaics properties compared with randomly oriented FMTs and pristine C70 film obtained from the spin coating. The compact, directional orientation and proper surface coverage of the FMT film enhanced the charge transport properties in the photovoltaic device.

Here we present self-assembled nanostructure of functional molecule fullerene (C60) at liquid-liquid interface. The nanostructured nanocrystals were grown at liquid-liquid interface of isopropyl alcohol (IPA) and C60 solution in butylbenzene under ambient condition of temperature and pressure, and characterized by Raman scattering, power X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The crystal formation mechanism is driven by supersaturation related to the low solubility of C60 in IPA. A slow diffusion of IPA towards the C60 solution causes unsaturation of C60 at the liquid-liquid interface and consequently small clusters of C60 is formed at the interface, which acts as the nucleation site. Further diffusion of IPA supplies the C60 molecules from bulk to the interface promoting the crystal growth. Based on SEM and TEM observation, the average size of the individual hexagonal bipyramid nanocrystal is found to be ca. 1.4 µm and the average size of their assembly is found to be approximately 2 µm. XRD measurements have shown that these materials are crystalline with mixed face-centered cubic (cell dimension: a = 1.352 nm, and V = 2.475 nm3) and hexagonal (cell dimension: a = 1.452 nm, c = 1.207 nm, c/a = 0.831, and V = 2.475 nm3) structures. Raman scattering measurements showed two Ag and six Hg vibration bands, which are similar to those obtained in the pristine C60.

Nanoporous activated carbons (ACs) were prepared from Lapsi (Choerospondias axillaris) seed powder by chemical activation with sodium hydroxide (NaOH) at different NaOH impregnation ratios. The prepared ACs were characterized by Fourier transform-infrared (FTIR) spectroscopy, Raman scattering, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Semi-quantitative information on the surface properties was obtained by estimating iodine number. FTIR spectra showed the presence of oxygenated functional groups such as hydroxyl, carbonyl, and carboxyl in the prepared ACs. Raman scattering showed clear D and G bands in the spectra. The intensity ratio of G and D band peak intensity was ca. 1.39 at lowest NaOH and Lapsi seed powder ratio 0.25:1 showing high graphitic degree. This ratio decreased with increase in the NaOH impregnation ratio and reached minimum ca. 0.94 (comparable with commercial AC) at NaOH and Lapsi seed powder ratio 1:1 demonstrating that higher NaOH impregnation reduces the graphitic structure of the carbon. XRD patterns showed two broad peaks at diffraction angles of approximately 25 and 43 degrees indicating the amorphous structure. Surface properties of the ACs (BET surface area, pore volume, and pore size distributions) were evaluated by nitrogen adsorption-desorption isotherm. Our ACs showed strong methylene blue adsorption property (maximum methylene blue is ca. 200 mg/g). Judging from the iodine number and methylene blue values, structure, and surface areas, it can be concluded that NaOH impregnation ratio is one of the key parameters to tune the surface properties of Lapsi seed stone-based activated carbons.

We present a simple wet chemical method to make thin film of silver nanoclusters on glass or silicon substrate. The method includes immersion of glass or silicon substrate into a saturated solution of silver nitrate in n-octanol. After 24 h, thin film of silver nanoclusters, which are micrometer-scale aggregates of silver nanoparticles with average size in the range of 80-100 nm, are formed on the substrate. The film is characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and UV-Vis spectroscopy. Potential use of the Ag nanoclusters as a surface-enhanced Raman scattering based sensing platform is demonstrated by measuring increased Raman signals from organic molecule adsorbed on the Ag nanoparticle clusters.

Activated carbons were prepared from Lapsi (Choerospondias axillaris) seed stone by zinc chloride (ZnCl2) activation at three different Lapsi seed powder (LSP):ZnCl2 ratios: 1:0.5 (AC-0.5), 1:1 (AC-1), and 1:2 (AC-2). The properties of these activated carbons (ACs), including effective surface areas, pore volumes, and pore size distributions were characterized from N2 adsorption-desorption isotherms. The ACs obtained were essentially nanoporous (including both micro- and mesoporous) with effective surface area ranging from 1167 to 1328 m2/g. Fourier-transform infrared (FTIR) spectroscopy showed the presence of functional groups on the surface of ACs. Scanning electron microscopy (SEM) images showed a high pore development in the ACs. X-ray diffraction (XRD) patterns showed that, in addition to the amorphous structure, ACs contains crystalline ZnO formed during the carbonization. Presence of amorphous carbon is further confirmed by Raman scattering, where we observed only D and G bands. Iron impregnated nanoporous AC has been found to be very effective for arsenic removal from ground water; amount of arsenic is decreased from ca. 200 ppb to 10 ppb. These experimental results indicate the potential use of Lapsi seed as a precursor material for the preparation of high surface area nanoporous activated carbons.

Using small-angle X-ray scattering (SAXS) we have investigated the shape and size of diglycerol monomyristate (designated as C14G2) nonionic surfactant reverse micelles in aromatic solvent ethylbenzene as a function of surfactant concentration, temperature, and water. When C14G2 is added into ethylbenzene globular type reverse micelles with maximum core diameter ca. 4.5 nm are formed under ambient conditions. The micellar structure (shape and size) did not change with the surfactant concentration. However, an increase in temperature decreased the micellar size due to an increase in the critical packing parameter (cpp). Surfactant becomes more lipophilic upon heating and the micellar curvature tends to become more negative at higher temperature. Addition of a small amount of water caused a significant micellar growth. For instance, incorporation of 0.3% water in the 5% C14G2/ethylbenzene system resulted in the formation of 2.1 time bigger micelles with a small water pool in the micellar core. Besides the micellar shape is modified into an ellipsoidal prolate, whose scenario can be understood in terms of hydration of the surfactant's headgroup. Hydration decreases the cpp and favors micellar growth. An increase of temperature of a water incorporated system decreased the micellar size due to dehydration, which is equivalent to rod-to-sphere type transition.

We have investigated the microstructural transformations of nonionic surfactant reverse micelles induced by surfactant molecular architecture, surfactant concentration, and temperature in nonaqueous media. The investigations were based on small-angle X-ray scattering (SAXS) and rheometry techniques. Polyglycerol polyoleic acid esters spontaneously self-assembled into reverse micelle in n-decane under ambient conditions, whose shape, size, and internal structure could be controlled by the surfactant molecular architecture, concentration, and temperature. The maximum size of the micelles was found to increase with an increase in the hydrophilic headgroup size of the surfactant. On the other hand, an opposite trend was observed with an increase in the number of oleate chain per surfactant molecules, which was well supported by rheology data; viscosity decreased with the number of oleate chain per surfactant molecule. The SAXS and rheology data have shown a clear evidence of one dimensional micellar growth with increase in the surfactant concentration. The relative viscosity, eta(r), of the reverse micelle exhibited steeper concentration dependence behavior than those predicted for a dispersion of spherical particles based on the Krieger-Dougherty relation which provided a clear evidence of the presence of elongated micelles at higher concentration. An ellipsoidal prolate-to-sphere type transition was observed upon heating.

Structure of diglycerol monomyristate (designated as C14G2) nonionic surfactant reverse micelles in aromatic solvent styrene has been investigated as a function of surfactant concentration, temperature, and water addition by using small-angle X-ray scattering (SAXS) technique. Structure of micelles in real-space so called pair-distance distribution function, p(r), was obtained by the generalized indirect fourier transformation (GIFT) evaluation of SAXS data. It was found that C14G2 spontaneously self-assembles into spheroid reverse micelles with maximum diameter approximately 3.0 nm when added into styrene under ambient condition. The micellar shape and size remained essentially the same despite a wide variation in surfactant concentration (5 to 30%) but an opposite trend was observed with the rise of temperature; size decreased by approximately 25% with increase in temperature from 25 to 75 degrees C. Addition of traces water favored micellar growth and eventually ellipsoid prolate type micelles were formed, whose scenario is understood in terms of decrease in the critical packing parameter (cpp); water hydrates the surfactant's headgroup and decreases cpp. At a particular concentration of water, increasing temperature decreased the micellar size due to dehydration of headgroup. It is interesting to note that size of 1.57% water incorporated micelle is approximately 2.5 times bigger than the empty micelles.