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In the oil-water separation, the difficulty to recover and low hydrophobicity are key limitation factors for practical applications. In this paper, we design Cobalt ferrite hybird Polystyrene divinylbenzene microspheres (CoFe2O4/SDB), which were conducted through in-situ suspension copolymerization. The CoFe2O4 is prepared by low heat solid phase sol-gel method. It had been found that the CoFe2O4/SDB have a spherical structure, good adsorption behavior, highly hydrophobicity and even superhydrophobicity. The adsorption capacity of CoFe2O4/SDB composites could absorb kerosene up to 6 times of its own weight. Interestingly, kerosene can be easily separated from the surface of CoFe2O4/SDB particles with ultrasonic operation. CoFe2O4/SDB particles can still maintain good hydrophobicity and adsorption capacity of kerosene after 11 cycles after drying. With in situ polymerization of St、DVB and CoFe2O4, CoFe2O4/SDB as a promising absorbent of kerosene which has great potential in application of oil-water separation.

A precise probe that can be applied in a variety of situations, such as both environmental sensor and in vitro imaging, is very attractive and promising. Here, we firstly reported a kind of nitrogen-rich carbon dots (N-CDots) growing during hydrothermal treatment, which emit bright and colorful fluorescence can be utilized as a reliable probe for Ferric ions (Fe3+) detection and bio-imaging. The nitrogen/carbon molar ratio (N/C) in N-CDots is as high as 39.9%. It is the high nitrogen content which provides N-CDots high quantum yield (at excitation wavelength of 365 nm, 400 nm, 440 nm: 34.8%, 27.6%, 22.3%) and thus high sensitivity and bright imaging when detecting Fe3+ and labeling cells, respectively. Regards to Fe3+ detection, the N-CDots show really low detection limit (7.6 nM), high selectivity when 16 kinds of other cationic ions are present and high accuracy to determine the concentration of Fe3+ in tap water. Regards to bio-imaging, the N-CDots showing low toxicity, are successfully loaded into cells and emit colorful florescence in cytoplasm and cytoderm. Furthermore, the N-CDots possess good water dispersibility, excellent photochemical stability and excitation dependent behavior, revealing the big potential for practical applications.

Carbon dots (CDots), generally small carbon nanoparticles with surface passivation by a soft corona-like layer of mostly organic species, have been actively pursued for potential applications in optoelectronics, including various functions that have been served by some popular fullerene derivatives. For the preparation of CDots, chemical functionalization of pre-processed and selected small carbon nanoparticles by organic molecules, so far mostly molecules with primary and secondary amine groups, has been an effective method. In this study, carbon nanoparticles were functionalized by N-ethylcarbazole (NEC) under microwave-assisted reaction conditions for NEC-CDots, analogous but with advantages to the CDots of surface functionalization by poly(N-vinylcarbazole) (PVK, which holds a special place in optoelectronics). NEC molecules can apparently be activated under the reaction conditions for reactive functionalities such as radicals to bind to surface carbons of the nanoparticles, consistent with the observed high stability of NEC-CDots. These dots, likely with a unique surface passivation scheme, exhibited optical properties and photoinduced redox characteristics similar to those found in other high-performance CDots. The potentially broad applicability of the new functionalization approach is discussed, so are implications of the unique surface passivation of carbon nanoparticles by the carbazole moieties.

Fullerene cages are known as being able to participate in radical initiated copolymerization reactions with vinyl monomers for polymer-functionalized fullerenes. In this work, poly(N-vinylcarbazole) (PVK) was selected as a representative of electronic polymers in the functionalization of fullerene C60 by the same copolymerization reaction to yield the PVK–C60. Similarly found was that small carbon nanoparticles could also participate in the same copolymerization reaction for the nanoparticles to be surface-functionalized and -passivated by the attached PVK polymers, which are structurally adhering to the general definition on carbon dots (CDots), thus PVK–CDots. In the comparison between PVK–CDots and PVK–C60, the former was found to be more absorptive and therefore more effective in photon harvesting across the visible spectral region and also brightly fluorescent, orders of magnitude more so than the latter. Similar to the PVK–C60 and C60 cages in general, the PVK–CDots exhibited significant photoinduced electron accepting characteristics and, at the same time, also extraordinary electron donating abilities that are not available to fullerenes. Because fullerene-based composites with electronic polymers including PVK have found significant applications in optoelectronic devices and systems, the prospect of CDots represented by the PVK–CDots for similar purposes is discussed.

As far as the longitudinal relaxivity (r1) is concerned, gadolinium ions (Gd3+)-based MRI contrast agents modified by traditional carriers do not appear to be far superior to the clinically used Magnevist. In this study, a type of MRI contrast agent (Gd3+@CGO) possessing a significantly high r1 value was easily prepared using a carboxyl-functionalized graphene oxide (CGO) as a nanocarrier to directly interact with GdCl3·6H2O. With 2.8 wt% of Gd3+ loaded on CGO, the prepared Gd3+@CGO shows good dispersibility in water and possesses r1 of 63.8 mM−1 S−1, which is 14 times higher than that of Magnevist. It is exciting to note that Gd3+ anchored on CGO remains stable at least for one year, probably relying on the electrostatic adsorption and physical encapsulation effect of CGO towards Gd3+.

A copper nanoparticles (CuNPs) colloid was synthesized by reduction of cupric sulfate with hydrazine hydrate in the presence of cetyltrimethyl ammonium bromide (CTAB) and poly(N-vinylpyrrolidone) (PVP). A uniform copper nanoparticles/polystyrene (CuNPs/PS) composite was further synthesized via in situ emulsion polymerization. The morphologies, structures, as well as thermal stabilities of the CuNPs and the CuNPs/PS composite were characterized by TEM, UV–vis, X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), Thermal gravimetric (TG), and gel permeation chromatography (GPC). The CuNPs are spherical with an average particle size of 10–20 nm. XRD shows that there is no copper oxide in the synthetic CuNPs. The CuNPs/PS composite particles have a narrow size distribution and an average particle size of 10–40 nm. TG indicates that the uniform CuNPs/PS composite has a better thermal stability than virgin polystyrene. GPC shows that the polystyrene of the CuNPs/PS composite has a higher molecular weight and a lower polydispersity index than virgin polystyrene.