A monolithic 3D hybrid of graphene and carbon nanotube was synthesized by two-step chemical vapor deposition. Owing to its superhydrophobic and superoleophilic properties, it can selectively remove oils and organic solvents from water with high absorption capacity and good recyclability.

The effects of temperature and concentration on poly(ethylene oxide)-poly(propylene oxide)poly(ethylene oxide) (PEO-PPO-PEO) block copolymer properties in aqueous solutions were studied by Fourier transform infrared (FTIR) spectroscopy. The temperature-dependent changes of some bands were used to denote the critical micellization temperatures (cmt). It was deduced that the appearance of the symmetric deformation band of anhydrous methyl groups in the spectra of aqueous Pluronic F127 solutions at temperature below the cmt means the existence of a hydrophobic microenvironment. The appearance of the symmetric deformation band of hydrated methyl groups at temperature above the transition region indicates that the micellar core must contain a certain amount of water. The proportion of anhydrous methyl groups was increased during the micellization process with the decrease of the proportion of hydrated methyl groups. The cmt values of Pluronic F127 in aqueous solutions were decreased with an increase of concentration. In the meantime, the water content in the micellar core was also decreased. The effect of gelation on the spectral behavior of Pluronic F127 in aqueous solutions is too weak to be observed by the FTIR technique. It was found that a certain part of the PEO segments of Pluronic F127 in aqueous solutions are in the crystalline state, which is not caused by micellization and gelation. The proportion of PEO segments in the crystalline state was increased with an increase of temperature.

The micellization of four triblock copolymers of the poly(ethylene oxide)x-poly(propylene oxide)y-poly-(ethylene oxide)x type (Pluronic P103, P104, P105, and F88) in aqueous solutions versus temperature is followed by Fouier transform-(FT-) Raman spectroscopy. The frequencies and relative intensities of C-H stretching bands in FT-Raman spectra are sensitive to the local polarity and conformation of block copolymer chains, and their variations with temperature are indicators of micellization. Therefore, the critical micellization temperatures of these copolymers of 10% concentration in aqueous solutions are determined. The deconvolution method is used to resolve the overlapping bands in the C-H stretching region, and the deconvoluted spectra provide information about the structural and microenvironmental changes of ethylene oxide (EO) and propylene oxide (PO) blocks, respectively. The hydration of the EO chains in the corona is found to diminish with increasing temperature, and the conformation changes to a more disordered structure. The structure of PO chains changes from a more polar, gauche conformation at low temperatures to a less polar, stretching conformation at high temperatures. The micellization is explained by the change in structure and microenvironment of the EO and PO units. The results confirm the leading role of the hydrophobic PO units in micellization, and reveal a favorable contribution of the hydrophilic EO units.

Tartrazine is an artificial azo dye commonly used in food products. The present study evaluated the interaction of tartrazine with two serum albumins (SAs), human serum albumin (HSA) and bovine serum albumin (BSA), under physiological conditions by means of fluorescence, three-dimensional fluorescence, UV-vis absorption, and circular dichroism (CD) techniques. The fluorescence data showed that tartrazine could bind to the two SAs to form a complex. The binding process was a spontaneous molecular interaction procedure, in which van der Waals and hydrogen bond interactions played a major role. Additionally, as shown by the UV-vis absorption, three-dimensional fluorescence, and CD results, tartrazine could lead to conformational and some microenvironmental changes of both SAs, which may affect the physiological functions of SAs. The work provides important insight into the mechanism of toxicity of tartrazine in vivo.

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