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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.

Styrene–divinylbenzene copolymer (SDB) is a key material for preparing Pt/SDB hydrophobic catalyst, which could be used for the treatment and purification of tritiated water. In this paper, a modified SDB (MSDB) carrier based on tert-butyl styrene (t-Bu-St), methyl methacrylate (MMA), styrene (St) and divinylbenzene (DVB) was prepared by aqueous suspension polymerization. Static adsorption experiment shows that the MSDB has the best adsorption performance at the molar ratio of St, DVB, t-Bu-St and MMA of 1:0.85:0.3:0.3 with n-heptane as porogen. The adsorption behavior of MSDB is analyzed by theoretical formulas. Data show that the adsorption process is in accordance with the Lagrange pseudo-first-order kinetics and Freundlich isotherm (1/n

Suffering from high inherent toxicity generated from heavy metals in semiconductor quantum dots and a complex preparation process, the medical application of conventional gadolinium(III)/semiconductor quantum dot-based magnetic resonance/fluorescence multimodal imaging (MRI/FI) contrast agent has been limited. In this paper, a new kind of biocompatible carbon quantum dot functionalized by gadolinium(III) chelates (named as Gd(III)/CQDs) was obtained through one-step pyrolysis of gadopentetate monomeglumine, which provides simultaneously a carbon source and a gadolinium(III) source. The Gd(III)/CQDs show good magnetic resonance response and photoluminescence properties with longitudinal relaxation rate and quantum yield of 5.5–6.4 mM L−1 S−1 [Gd(III)%, 0.5 mM] and 2.6–8.9%, respectively. The Gd(III)/CQDs with diameters in the range of 2–3 nm can be well dispersed in deionized water, phosphate-buffered saline buffer solution or culture medium to form a stable dispersion, which with low cytotoxicity can penetrate into cells and show green fluorescence (excitation at 488 nm), presenting a great potential to be used as an MRI/FI contrast agent.

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.

The passivation of carbon dots (CDs) are usually implemented through coupling reactions, which requires either specific functional groups on the surface of CDs or multiple steps. In this paper, we propose a feasible method to passivate CDs via in-situ free radical polymerization, which has no dependence on functional groups and thus is suitable for CDs prepared via either bottom-up or top-down route. Taking bare CDs that cut from active carbon by top-down method as an example. When putting acrylic acid, sodium methallyl sulfonate and acrylic phosphate ester as monomers into the bare CDs solution along with ammonium persulfate, stirring at room temperature for 2h, the monomers were polymerized and formed terpolymer-passivated CDs (T-CDs) of which quantum yields (QY) increased obviously. The QY of the bare CDs and the T-CDs were 0.2% and 29.1%, respectively. More interestingly, the bare CDs were found capable of constructing a redox-initiated couple with ammonium persulfate to initiate polymerization. Another example token to further approve the feasibility and universality of “in-situ free radical polymerization” passivation method is our reported poly (N-vinylcarbazole)-passivated CDs (PVK-CDs) that prepared by bottom-up method. The PVK-CDs were synthesized via thermal treatment of a mixture composed of citric acid and N-vinylcarbazole molecules at 300 °C for 2 h. During the process the citric acid was carbonized to provide pristine CDs and N-vinylcarbazole was in-situ polymerized on the surface of the pristine CDs through thermal initiation, which enhances the fluorescence QY up to 40%.

Based on the intramolecular charge transfer (ICT) fluorescence quenching mechanism, a ready-to-use colorimetric coumarin coordinative probe has been designed and successfully achieved for the efficient detection of Pd2+ in aqueous buffer media (pH 7.0), which promisingly meets real-world challenges through a facile synthetic route, fast response, by-eye visualization, regenerative-action, high selectivity and sensitivity. The UV–vis spectra, mass spectra and density function theory studies have indicated that a 1:1 complex is formed between the probe and Pd2+. The detection limit of Pd2+ is up to 2.9 × 10−7 M. This reagent could even be used for estimation of Pd2+ in samples with its known concentrations with considerable accuracy (ca. 4.1-4.8% error). Moreover, the binding affinity and fluorescence quenching degree of 1 with Pd2+ are superior to those of 2. It has been demonstrated that the sensitive property of the chemosensors for Pd2+ is highly dependent on the fine structure of the conjugated compounds.

An ideal proppant showing super-hydrophobicity and enough strength to bear high closure stress is revolutionary for the effective exploration of gas or oil in shale. Here, the ideal proppants were obtained by wrapping specially treated phenol formaldehyde resins around the cover of the traditional ceramsites. The resin coating is patterned with innumerable fluorine-modified silica nanoparticles, whose thickness is controllable. Benefitting from the low surface energy of fluorine, nano-roughness structures from nano-silica, and the adhesive action of the resin, the modified proppant exhibits awesome properties. The nanoparticle-patterned resin gives the ceramic proppants a water contact angle of 157.8° that has been proved to be stable after being treated in strong acid, thus dramatically accelerating the fracture conductivity for oil by 150% whereas totally preventing water passing through. Besides, it is the resin that reduces the crushing rate of the proppants by 52% and decreases the density of the proppants to 1.63 g/cm³.

There are a few bimodal molecular imaging probes constructed by gadolinium (3+) ions in combination with carbon quantum dots (CQDs), and the reported ones show such obvious drawbacks as low luminous efficiency and weak MRI contrast. In the paper, a kind of CQDs photoluminescence materials with magnetic resonance response was prepared by hydrothermal method and employing gadopentetate monomeglumine (GdPM) as a precusor. Here, the GdPM plays a role of not only carbon source, but also gadolinium (3+) sources. When the GdPM aqueous solution with a concentration of 4 mg mL −1 was pyrolyzed under 220 °C and 2.0 MPa for 8 h, an optimal CQDs was obtained which are doped with gadolinium (3+) ions in both chelates and Gd 2 O 3 (named as Gd 3+ -CQDs). The average diameter of the Gd 3+ -CQDs is about 1.6 nm, which show a high photoluminescence quantum yield of 7.1%, as well as high longitudinal relaxivity ( r 1 ) of 9.87 mM −1 s −1 . And owing to the unconspicuous cell toxicity, the Gd 3+ -CQDs show big possibility for clinical application in magnetic resonance/fluorescence bimodal molecular imaging.

Poly (N-vinyl carbazole) functionalized carbon dots (PVK-CDots) exhibiting significant photoinduced redox properties show great potential to be applied in opto-electro devices and systems. Here, we further make sure the PVK-CDots are promising candidates for developing solar cells after we designed a “one-pot” procedure to prepare PVK-CDots nanocomposites with high carbon content. The “one-pot” procedure is such that when citric acid is thermally carbonized into a carbon core, the N-vinyl carbazole is thermally initiated in situ to polymerize on the surface of the carbon core as passivation layer. The prepared PVK-CDots containing very high carbon content (about 36 %) are strongly absorptive and therefore effective in photon harvesting and also brightly fluorescent across the visible spectral region, which as expected exhibits significant photoinduced redox properties. Taking perovskite solar cell as an example, the PVK-CDots are qualified to act as a hole transport layer (HTL) material according to the alignment of energy levels.

A postsynthetic self-assembly system was designed to investigate a construction process from suspended polyaniline (PANI) molecules to condensed aggregates. The conventionally synthesized PANI was dissolved in polar solvent and introduced into acidic medium with electrolytes similar to the aniline chemical oxidative polymerization (COP) medium. In this way, reaction interference that is usually encountered in the COP process could be avoided, and influences of medium conditions including organic electrolytes on the self-assembly behaviors of PANI were studied. It was discovered that, in a static aqueous medium with moderate pH and rich electrolytes, PANI molecules composed of bulk aggregates could self-assemble into well-dispersed nanoparticles with few structural changes. Electrostatic force is considered to dominate the self-assembly of PANI molecules as compared with other noncovalent interaction or the effect of soft templates such as ionic liquid and surfactant. The results are supposed to provide better understanding on the formation mechanism of micro/nanostructured PANI.

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+.

Silver nanoparticles (AgNPs) were synthesized in reverse microemulsions using silver nitrate as silver source, hydrazine hydrate as reducing agent, n-heptane as oil phase, cetyl trimethyl ammonium bromide (CTAB) as surfactant, and isoamyl alcohol as cosurfactant. A uniform silver nanoparticles/polystyrene (AgNPs/PS) composite was further prepared by a reverse microemulsion polymerization method. The morphologies and structures of the AgNPs and the AgNPs/PS composite were characterized by UV-visible spectroscopy (UV–vis), X-ray diffraction (XRD), fourier transform infrared spectra (FTIR), and transmission electron microscopy (TEM). Furthermore, the molecular weight of the AgNPs/PS composite was measured by gel permeation chromatography (GPC), and the thermal stability of the AgNPs/PS composite was determined by thermal gravimetric (TG) analysis. Results show that the AgNPs have a particle size of 3–10 nm, and are almost spherical, uniform, and monodisperse both in a AgNPs colloid and in the AgNPs/PS composite. There are no characteristic peaks of silver oxide in the synthetic AgNPs and AgNPs/PS composite. The AgNPs/PS composite has a better thermal stability and a higher molecular weight than virgin PS. POLYM. COMPOS., 35:1325–1329, 2014. © 2013 Society of Plastics Engineers

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.