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Monodispersed hollow MnS nanospheres have been prepared through a solvothermal method using an imidazoline derivative as the morphology-directing reagent. The composition and morphology of synthesized MnS were characterized by powder XRD, SEM, and TEM. The MnS nanospheres were then mixed with chitosan and used as an immobilization matrix for redox protein of hemoglobin. UV–vis and FT-IR spectra showed that the configuration of hemoglobin in the composite film was well maintained. Electrochemical experiments demonstrated that the charge transfer process of Hb was greatly promoted by the MnS. The modified electrode also showed good electrocatalysis toward hydrogen peroxide with the linear range from 0.8 to 15.2 µM. The detection limit and Michaelis–Menten constant were determined to be 0.092 and 4.33 µM, respectively. When the biosensor was utilized for the detection of hydrogen peroxide in contact lens care solution, satisfactory results were obtained.

A broccoli-like bismuth sulfide (bBi2S3) was synthesized via a solvothermal method using a self-made imidazoline derivative of 2-undecyl-1-dithioureido-ethyl-imidazoline as the soft template. The morphology and chemical constitution of the product were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Electrochemical characterization experiments show that the bBi2S3 has the higher specific surface area and standard heterogeneous electron transfer rate constant than the rod-like Bi2S3 (rBi2S3). Hemoglobin (Hb) was then chosen as a protein model to investigate the electrocatalytic property of the synthesized bBi2S3. The results show that Hb entrapped in the composite film of chitosan and bBi2S3 displays an excellent direct electrochemistry, and retains its biocatalytic activity toward the electro-reduction of hydrogen peroxide. The current response in the amperometry shows a linear response to H2O2 concentrations in the range from 0.4 to 4.8µM with high sensitivity (444µAmM(-1)) and low detection limit (0.096µM). The Michaelis-Menten constant (KM(app)) of the fabricated bioelectrode for H2O2 was determined as low as 1µM. These results demonstrate that the synthesized bBi2S3 offers a new path for the immobilization of redox-active protein and the construction of the third-generation biosensors.

A highly sensitive impedimetric DNA biosensor based on rod-like bismuth sulfide nano (rBi 2 S 3 ) and polyaniline (PANI) nanocomposite film modified ionic liquid-carbon paste electrode (IL-CPE) has been developed. The rBi 2 S 3 particles were first dropt on IL-CPE that was constituted with 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF 6 ) and graphite powder, and then the PANI polymer was deposited on the surface of rBi 2 S 3 through potentiodynamic polymerization using aniline as the source, forming the PANI capped Bi 2 S 3 nanocomposite. The morphologies and electrocatalytic property of the composite were characterized by scanning electron microscopy (SEM) and electrochemical techniques including electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), respectively. The integrated advantages such as the large surface area, excellent electronic conductivity, easy to fabrication, and good biocompatibility make the electrode favorable for DNA immobilization and hybridization detection. It was found that remarkable increase of electrochemical impedance was observed after the probe DNA modified electrode was hybridized with the target DNA. The dynamic detection range was determined to be from 1.0 × 10 −15 to 1.0 × 10 −11 M with a detection limit of 4.37 × 10 −16 M. The DNA biosensor also displayed good regeneration ability, reproducibility and stability.

In this study, by using Al2(SO4)3 aqueous solution and urea as raw materials, hollow microspheres structured boehmite was successfully synthesized only after 30 min reaction time at 180 °C via an additive-free and time-saving microwave hydrothermal route. The final products were characterized by techniques of X-ray diffraction (XRD), transmission electronic microscope (TEM), scanning electron microscope (SEM) and Fourier transform infrared spectrometry (FTIR). To investigate its crystal form and morphology evolution process, samples subjected to different reaction durations were prepared and characterized. The pivotal influence factors on boehmite morphology, such as reaction temperature, dosage of urea and microwave power range were discussed based on the experiment facts.

The controlled synthesis of inorganic materials with desired morphologies and architectures at micro- and nanoscale levels is of great importance to inorganic material design. In this study, we describe an innovative morphology control concept named anions competition method. The key point is to introduce another concomitant raw material to not only share the total demand of cations but also provide competitive anions required by the morphology control. Take boehmite for example, aluminum sulfate was consciously and proportionally introduced as another concomitant raw material into aluminum chloride/aluminum nitrate–urea hydrothermal process to form SO42 −–Cl− and SO42 −–NO3− competition systems. Boehmite from lamellar assemblies to hollow microsphere morphologies was facilely synthesized by succinctly altering the relative proportion of SO42 −:Cl− and SO42 −:NO3−.

An additive-free hydrothermal approach has been developed for the large-scale synthesis of lamellar morphology boehmite powders by merely using Al(NO3)3 and urea as raw materials conducted in an autoclave of 10 L capacity. The hydrothermal synthetic and calcined products were characterized by techniques of X-ray diffraction(XRD), transmission electronic microscopy(TEM), scanning electron microscope(SEM), Fourier transform infrared spectrometry (FTIR) and thermogravimetric analysis (TGA/DTA). The microscope analysis manifested that the lamellar boehmite was around 100–200 nm in width and 500–1000 nm in length. The opportune influence factors on boehmite morphology, such as dosage of urea and reaction temperature were determined by single-factor experiment method. To investigate its crystal form and lamellar morphology evolution process, samples subjected to different reaction durations from 2 h to 12 h were prepared and characterized by techniques of TEM, SEM and XRD. A spontaneous morphology evolution mechanism driven by Ostwald ripening was proposed based on the experimental facts.

Boehmite (γ-AlOOH) hollow microspheres were synthesized via a convenient hydrothermal route. To investigate its crystal form and morphology formation process, samples subjected to different reaction durations from 1 to 24 h were prepared and characterized by techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM). A spontaneous morphology evolution mechanism driven by Ostwald ripening and dissolution–renucleation was proposed based on the experimental facts. We think that systematically understanding and hereby manipulating the morphology evolution process will contribute to fabricate novel morphologies of the materials.

A facile one-pot synthesis of ZnS hollow spheres has been carried out via a chemical transformation induced inside-out Ostwald ripening process from a single source precursor. The size and shell thickness of the ZnS hollow spheres can be controlled by adjusting the reaction temperature and reaction time, respectively. Photoluminescence spectra show a dominant emission peak at 470 nm accompanied by several weaker peaks. UV–vis measurement reveals that the obtained ZnS hollow spheres exhibit “hollow effect”. The formation process of ZnS hollow spheres has been discussed.

Flower-like and rod-like boehmite has been synthesized using a hydrothermal route in a buffer solution. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS) and Fourier transform infrared (FTIR). The SEM and the TEM images of products obtained after different processing times reveal that the buffer solution plays an important role in the rod-like boehmite formation. This approach may allow us to have a better control of the size and morphology of the crystalline boehmite. And the surface area of boehmite hollow microspheres was calculated using Brunauer–Emmett–Teller (BET) model. The possible formation mechanism was proposed and discussed.

CdS crystals with spherical morphology have been prepared by a solvothermal method using a self-made novel block-like imidazoline-gemini surfactant quaternary ammonium salt of di (2-undecyl-1-formyl aminoethyl thiourea imidazoline) hexanediamine (SUDEIHDI) as the shape-controlling agent. The obtained CdS products are characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), infrared ray spectroscopy (IR), UV-vis absorption spectroscopy, and x-ray diffraction (XRD), respectively. In addition, the formation mechanism for the CdS sphere was also discussed.

Composite hollow microspheres of CeO2-ZrO2 were prepared by using anionic PSA latex particles as template and then calcining the PSA core particles at 600°C. The samples were characterized by XRD, TEM, TG, SEM, EDS, and FT-IR spectra. The effects of the proportion of CeO2 on the structure of the microspheres were also studied. Electrochemical assay showed that the CeO2-ZrO2 composite hollow spheres hydrided with chitosan could be used as a novel biosensing material to detect the direct electron transfer of hemoglobin.

γ-AlOOH architectures with hollow and self-encapsulated structures have been selectively synthesized by a facile one-step wet-chemical route. It is interesting to note that the condensed cores could be self-encapsulated into the hollow shells, and that the hollow shells were constructed with γ-AlOOH nano-flakelets and showed urchin-like morphologies. γ-Al2O3 hollow and self-encapsulated architectures have been synthesized by thermal decomposition method using the as-synthesized γ-AlOOH as precursors, and the morphologies and microstructures of γ-AlOOH have sustained very well. The surface area of γ-Al2O3 hollow microspheres was calculated to be 116.9 m2 g−1.

PurposeThe purpose of this paper is to investigate the tribological properties of MoS2 nano‐sized hollow spheres in liquid paraffin (LP) and the corresponding action mechanism. Morever, its feasibity of industrial application as an oil additive in the industrial lubrication field is also explored.Design/methodology/approachThe tribological properties of MoS2 nano‐sized hollow spheres (NH‐MoS2) modified by Cyanex 301(di‐(2,4,4‐trimethylpentyl) dithiophosphinic acid) with size of 200 ∼ 300 nm in LP are studied and compared with those of the commercial colloidal MoS2 (CC‐MoS2) on a four‐ball tester and an Optimol SRV Oscillating friction and wear tester in a ball‐on disk configuration. The worn surfaces of the lower flat disc are examined with a scanning electron microscopy and an X‐ray photoelectron spectroscopy, respectively.FindingsResults show that NH‐MoS2 is a better extreme‐pressure additive and anti‐wear (AW) and friction‐reducing additive in LP than CC‐MoS2. Under the optimum concentration of 0.5 per cent for both NH‐MoS2 and CC‐MoS2 and the load of 400 N, the friction coefficient of NH‐MoS2 + LP and CC‐MoS2 + LP decreases about 43.8 and 6.3 per cent, and the wear volume loss decreases about 60.3 and 12.0 per cent compared with the pure LP. The boundary lubrication mechanism for NH‐MoS2 + LP can be deduced as the effective chemical adsorption protective film formed by the long chain alkyls R and active elements (S and P) in the modification layer and tribochemical reaction film containing the tribochemical products of the additive. Moreover, sliding and rolling frictions co‐exist in NH‐MoS2 + LP, doing contributions to the good tribological properties as well.Originality/valueIn this paper, the Cyanex 301‐modified MoS2 nano‐sized hollow spheres with diameter of 200 ∼ 300 nm are firstly added into LP to investigate its tribological properties. The excellent AW and friction‐reducing properties indicate that this MoS2 hollow spheres product is a good oil additive, and the fundamental data presented here will be useful for its further industrial application in the future.

This article presents a facile surfactant‐assisted route to the fabrication of ZnS hollow spheres with diameter of about 0.5∼1 µm in ethanol at room temperature. The surfactant quaternary ammonium salt of 2‐undecyl‐1‐dithioureido‐ethyl‐imidazoline (SUDEI) prepared in our lab acts as surface‐modifying agent, morphology‐controlling agent and stabilizing agent in the whole procedure. TEM, SEM, XRD, EDXA, UV‐vis, and FTIR were used to characterize the ZnS products. The influences of reaction conditions were discussed while a formation mechanism was proposed to explain this peculiar morphology. The ZnS hollow spheres product is of excellent dispersion capacity and stability in liquid paraffin (LP) and the tribological properties of LP containing ZnS hollow spheres were studied with an Optimol SRV (SRV is the abridged name for German Schwingung, Reibung, Verschleiss) oscillating friction and wear tester, showing excellent anti‐wear and friction‐reducing performances. The action mechanism of the ZnS hollow spher...

Several ZnO nanoarchitectures have been selectively prepared through hydrothermal method including urchin-shaped, flower-shaped, butterfly-shaped, and cacti-shaped microstructures. The influence of reaction temperature and the concentration of amphiphilic copolymer on the morphologies and shapes of ZnO samples have been studied. The samples were characterized using XRD, TEM, and SEM. It was found that ZnO nanorods or their assemblies were fabricated at higher temperature, whereas ZnO nanosheet architectures were produced at lower temperature. These flower-shaped architectures possess high BET surface area of 27.43 m2/g. Room temperature UV-VIS and PL spectra of the as-obtained ZnO nanoarchitectures have been examined. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Uniform cubic‐shaped PbTe and PbSe nanocrystals have been synthesized through the surfactant‐assisted hydrothermal reaction between Pb(NO3)2 and Te or Se powders with hydrazine hydrate as reducing reagent. The products were characterized by powder x‐ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that the shapes of nanocubes are well controlled by using ethylenediaminetetraacetic acid as chelating reagent and in the presence of poly(vinyl‐pyrrolidone).

Tribological properties of MoS2 micrometer spheres modified by self-prepared surfactant as an additive in liquid paraffin (LP) are studied and compared with those of the commercial colloidal MoS2 on a four-ball tester and an Optimol SRV oscillating friction and wear tester. The worn surfaces are examined with SEM and XPS, respectively. Results show that MoS2 micrometer sphere is a much better extreme-pressure additive and anti-wear and friction-reducing additive in LP than the commercial colloidal MoS2. The boundary lubrication mechanism can be deduced as an effective chemical adsorption protective film formed by the long chain alkyl and active elements (S and N) in the prepared surfactant and tribochemical reaction film composed of the tribochemical reaction products of the additive. Moreover, sliding and rolling frictions exist simultaneously in the MoS2 micrometer spheres /LP lubricating system, which also do more contributions to the good tribological properties.

The tribological properties of MoS 2 microsized spheres (MS-MOS 2 ) with diameter of 0.5-3 μm modified by self-prepared surfactant quaternary ammonium salt of 2-undecyl-1-dithioureldo-ethyl-imidazoline (SUDEI) as an additive in base oil 500 SN were investigated and compared with those of commercial colloidal MOS 2 (CC-MOS 2 ) on a four-ball tester and an Optimol SRV oscillating friction and wear tester in a ball-on-disk contact configuration. The worn surfaces of the bottom flat disk were examined with scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the MoS 2 microsized spheres product was a much better extreme-pressure additive and antiwear and friction-reduction additive in 500 SN than commercial colloidal MOS 2 (CC-MoS 2 ). Under the appropriate concentration of 0.1% and 0.25% for MS-MOS 2 and CC-MoS 2 and the load of 400 N, the friction coefficient of MS-MOS 2 /oil and CC-MoS 2 /oil decreased about 25.0% and 12.5% and the wear volume loss decreased about 50.4% and 12.9% compared with the pure base stock. The boundary lubrication mechanism could be deduced as the effective chemical adsorption film formed by the long chain alkyl (C 11 H 23 ) and active elements (S and N) in the surfactant SUDEI and tribochemical reaction film composed of the tribochemical reaction products.

ZnO whisker arrays have been prepared by a self-source procedure of the substrate under hydrothermal conditions. Zinc foils were used as a substrate and zinc-ion source for direct growth of ZnO whiskers. SEM observations revealed that the as-prepared ZnO whiskers exhibit hexagonal prism-like shape showing well-defined crystallographic facets and hexagonal pyramid-like sharp tips. The growth of ZnO whiskers in the initial stage has been recorded, and the growth mechanism was discussed in detail.

Mono-dispersed molybdenum disulfide solid spheres with the diameter of 0.5–2 μm have been successfully synthesized by a solvothermal method with a homemade quaternary ammonium salt of 2-undecyl-1-dithioureido-ethyl-imidazoline (SUDEI) as surfactant. The obtained solid spheres are characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The influences of reaction conditions are discussed while a mechanism is proposed to explain the formation of the peculiar morphology.

Mono-dispersed molybdenum disulfide micro-spheres with the diameter of 1-3 {mu}m have been successfully synthesized via extraction-solvothermal method at 150 deg. C. The extractant Cyanex 301 (di-(2,4,4-trimethylpentyl) dithiophosphinic acid) acted as phase transferring agent, reductant, sulfur source and morphology-controlling agent in the whole procedure. The obtained MoS{sub 2} micro-spheres were characterized by XRD, EDS, SEM, TEM, HRTEM, IR, UV-Vis and TG, respectively. The influences of reaction conditions were discussed while a mechanism was proposed to explain the formation of the micro-spheres. Moreover, the tribological properties of liquid paraffin (LP) containing Cyanex 301-modified MoS{sub 2} micro-spheres were also evaluated on a four-ball machine, showing that the obtained MoS{sub 2} product was an excellent oil additive in LP and such lubricant had good anti-wear and friction-reducing properties. - Graphical abstract: Mono-dispersed MoS{sub 2} micro-spheres with the diameter of 1-3 {mu}m were synthesized in gasoline via extraction-solvothermal method at 150 deg. C. The MoS{sub 2} product could be well dispersed into organic solvents again and the tribological properties of liquid paraffin (LP) containing MoS{sub 2} micro-spheres were improved.

Hollow spherical molybdenum disulfide has been successfully synthesized via a solvothermal method using Cyanex 301 as sulfur source and modification agent. The hollow spheres are characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction and Energy-Dispersive X-ray analysis. The influences of reaction conditions are also discussed while a mechanism is proposed to explain the formation of the peculiar morphology.

Anatase titania hollow spheres have been successfully prepared using styrene-acrylic acid copolymer (PSA) latex particles as template, which involves the deposition of inorganic coatings on the surface of PSA latex particles and subsequent removal of the latex particles by calcinations in air. Ti(SO 4 ) 2 instead of organometallic titanium was firstly used as precursor for the preparation of titania hollow spheres. The formation of anatase titania was confirmed by XRD analysis and the hollow structure of the samples was revealed by electron microscope.

Stable organic fluids containing Ag2S nanoparticles modified by Cyanex301 (di-(2,4,4-trimethylpentyl) dithiophosphinic acid) have been prepared directly in alkane via a solvent extraction synthesis method. The organic fluids are so stable that the nanoparticles do not precipitate at room temperature even after more than one year even when the content of Ag2S nanoparticles is as high as 42 g L−1. The Ag2S nanoparticles are characterized by XRD, TEM, IR, UV-vis and TG-DSC, showing that the particles are well modified by the extractant Cyanex301. The obtained nanoparticles can be well dispersed again in organic solvents and the new fluids are also very stable. The loading concentration of Ag2S nanoparticles prepared through the extraction synthesis method is much higher than that prepared via a two-step (preparation and dispersion) synthesis method and found to decrease with an increase of the solvent polarity. The tribological properties of the Ag2S nanoparticles modified by Cyanex301 in liquid paraffin (LP) for a steel–steel friction pair are evaluated on a four-ball machine, showing that such a fluid, LP+Ag2S, has a low friction coefficient.

CdS hollow spherical particles with different sizes have been prepared using core/shell fabrication method with poly-(styrene–acrylic acid) (PSA) latex particles as template. The sodium salt of extractant P204 (di-(2-ethylhexyl) phosphoric acid) was used firstly as the emulsifier in the template synthesis. The diameters of the polymer core decreased from 300 to 120 nm on average with increasing of the amount of emulsifier from 1.56 to 3.54%. As a result the diameters of the hollow spheres ranged from 350 to 150 nm. The products were characterized by TEM, IR and XRD, respectively.

Flake-like silver nanoparticles have been synthesized in large quantity by simply aging the aqueous solution of silver and urotropine in the presence of poly-(vinylpyrrolidone) (PVP). Silver nanoflakes of different shapes from circular to polygonal could be obtained in different reaction stages. PVP molecules play an important role in the anisotropic growth of silver nanoflakes. The as-synthesized silver colloidal solution remained stable for at least 1 month. Electron diffraction analysis showed that the nanoflakes are well crystallized. The UV-VIS absorption properties have also been studied.

Stable organic fluid containing silver nanoparticles modified by extractant Cyanex 301 (di‐(2, 4, 4‐trimethylpentyl) dithiophosphinic acid) has been prepared directly in alkane by the solvent extraction‐reduction method. Ag+ is extracted into alkane by Cyanex 301, then the obtained Ag+‐Cyanex 301 complex is reduced with solid sodium borohydride to obtain the organic fluids containing Ag nanoparticles. The organic fluids are so stable that the nanoparticles do not precipitate at room temperature for more than two months when the concentration of Ag nanoparticles is about 0.10 mol L−1. The nanoparticles are characterized by XRD, TEM, IR, UV‐Vis, and TG‐DTG, showing that Ag nanoparticles are well modified by the extractant. The obtained Ag nanoparticles can be dispersed well in organic solvent again, and the new fluids are very stable in air. The loading concentrations decrease with increase of solvent polarity.

Single crystal silver dendrites have been synthesized by heterogeneous reduction of AgNO3 in toluene solutions of a triblock copolymer (EO)(20)-(PO)-(70)-(EO)(20). The triblock copolymer stabilized system exhibits high stability, which makes sample handling and analysis simple. By this method. the concentration of Ag in the colloidal system can be as high as 8.5 g/L. TEM, XRD, IR, and UV-vis measurements are used to characterize the resulting hybrid systems. (C) 2004 Elsevier B.V. All rights reserved.

Fe 2 O 3 microcages, with uniform size and diameters of about 620 nm, have been successfully prepared by templating against styrene-acrylic acid (PSA) copolymer latex particles, which involves the deposition of Fe(OH) 3 coatings on the surface of latex particles and subsequent removal of the latex particles by calcinations. The cage-like structure of the samples was revealed by scanning electron microscope (SEM), and the formation of Fe 2 O 3 was confirmed by X-ray powder diffraction (XRD) analysis. The porous shells were constructed with Fe 2 O 3 nanoparticles, and the shell thickness is of 30–60 nm, matching the diameters of the Fe 2 O 3 nanoparticles.

In this study, we successfully established an additive-free microwave hydrothermal (M-H) route by only using Al 2 (SO 4 ) 3 aqueous solution and urea as raw materials. Core-shell structured boehmite was synthesized at 180 °C for the first time via a M-H route. The final product was characterized by techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM). On account of the fact that less reaction time usually means less energy consumption or more eco-friendly design, the M-H reaction time was successfully reduced to only 40 min by utilizing full microwave heating power and appropriate dosage of urea. To investigate the possible mechanism and influencing factors associated with the morphology and crystal form evolution process, samples subjected to different reaction durations were prepared and characterized.

Hollow spheres and thin films of Ni(OH)(2) and NiO with unusual form and hierarchical structures have been synthesized by a simple solution chemistry method. First, in situ formed Ni(OH)(2) nanoflakelets organized on the surface of styrene-acrylic acid copolymer (PSA) latex particles to form core/shell structures. Ni(OH)(2) hollow shells built up with nanoflakelets were obtained after subsequent removal of the core latex particles by dissolving PSA latex in toluene; the removal of the cores by calcinations would result in NiO hollow shells, also with hierarchical structures. BET calculation showed the surface area of the NiO hollow spheres was 156 m(2)/g. The nanoflakelets could also organize themselves into thin films with hierarchical structures. It is anticipated that these novel structures will have some unique applications in Ni-based batteries and other potentials.

Silver nanoshells on styrene–acrylic acid copolymer latex spheres (PSA) were deposited by an in situ chemical reduction method, ageing a colloid solution at 85 °C containing PSA latex, AgNO3, urotropine, and poly-(vinylpyrrolidone). SEM and TEM observations showed that the silver nanoshells were made of closely packed silver nanoparticles of different sizes and morphologies. UV–visible absorption spectra were recorded to investigate their optical properties.

Sheet-like CdS nano-crystal has been prepared successfully using the liquid crystal template formed in organophosphinic acid extractant (Cyanex272 or Cyanex302)–hexane–NaOH aqueous solution systems. To fairly copy the lamellar structure of the liquid crystal, it is very important to optimize the experiment conditions especially in the procedure of template preparation. The amount of Cd2+ added should be appropriate to avoid the liquid crystal structure being damaged, and the formation of well controlled sheet-like CdS nano-crystal prefers a thinner water layer.

CdS hollow spherical particles with average diameter of 800 and 850 nm have been prepared using core/shell fabrication method with poly-(styrene-acrylic acid) (PSA) latex particles as template. TEM images show that smoothly coated core/shell composite particles have been fabricated by multicycles of coating in optimum concentration of reactants. CdS hollow spheres were obtained after removing the template by dissolving the polymer in the organic solvent, and the wall thickness is about 40–100 nm.

The boehmite (γ-AlOOH) hollow microspheres were synthesized after 120 min reaction time at 150 °C for the first time via a microwave hydrothermal route, using Al2(SO4)3 aqueous solution and urea as raw materials and amphiphilic copolymer of P(St)-b-P(HEA) as structure-directing agent. The final product was characterized by techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM). The microscope analysis revealed that the boehmite (γ-AlOOH) hollow microspheres were around 1–2 μm in diameter and a shell thickness of approximately 200 nm. To investigate the influencing factors and formation mechanism of the as-obtained boehmite hollow microspheres ultra-fine powders, samples subjected to different reaction durations were also studied by SEM. A self-assembly morphology evolution mechanism was proposed based on the experimental facts.

By using Al 2 (SO 4 ) 3 aqueous solution and urea as raw materials, spherical and laminar morphology amorphous aluminum hydroxide (Al(OH) 3 ) ultra-fine powders were synthesized after 120 min reaction time at 150 °C via a microwave-hydrothermal route. It is interesting to note that the spherical particles could be self-encapsulated into the hollow shells which were constructed with the laminar morphology particles to form core-shell structured ultra-fine powders. The microscope analysis revealed that the spherical cores were around 1 μm and the shells were about 2–3 μm in diameter, respectively. To investigate the influencing factors and formation mechanism of the as-obtained core-shell structured amorphous aluminum hydroxide (Al(OH) 3 ) ultra-fine powders, samples subjected to different reaction durations were also studied.

This paper describes a one-pot surfactant-assisted hydrothermal method for the synthesis of Ag-TiO 2 composite hollow structures with high photocatalytic activity. TEM measurement reveals that the sample is composed of hollow spheres and their tube-like aggregates. The surfactant cetyltrimethylammonium bromide (CTAB) plays a key role in the construction of the Ag-TiO 2 hollow structures. The Ag-TiO 2 hollow structures showed effective photocatalytic activity for the decomposition of methyl orange.

In this paper, we developed a facile low-temperature solution route to prepare radical-shaped ZnO microprisms and to deposit metal silver on the surface of ZnO to form Ag/ZnO microstructures. The samples were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. Experimental results show that the deposition of metal Ag nanospecies can be achieved successfully by simply aging the solution at 75 °C, and the radical-shaped microstructures of ZnO are well maintained. The Ag/ZnO microstructures exhibit much lower PL emission intensity and much higher photocatalytic activity than those of radical-shaped ZnO microprisms.

Conductivities of water-in-oil (w/o) microemulsions of the sodium salt of mono(2-ethylhexyl)phosphoric acid-n-hexane-n-pentanol-water system have been measured during dilution processes with varying amounts of water present. The conductivity does not change significantly if the microemulsion is continually diluted, but does change significantly with different amounts of water added at the beginning of microemulsion formation. The water amount added at the beginning affects the structure parameters of the microemulsion, such as the radius of the water pool (r) and the mean aggregation number of the surfactant molecules in a droplet ( n ∗ ), indicating that an optimum r and/or n ∗ value may exist that gives maximum conductivity. The conductivity behaviour of the microemulsions has also been studied based on charge carrier transition by the “sticky collision of droplet” mechanism. The activation energy ΔE was determined. The results showed that there was a maximum in the ΔE value when the water content increased up to the percolation threshold value.

Equilibrium and kinetic studies have been carried out on the extraction of nickel from sulfate solutions using bis(2,2,4 trimethylpentyl) phosphinic acid HDTMPP, “Cyanex 272tm”- It was found that nickel extraction in HDTMPP was favored by the presence of sodium in the organic phase and that equilibrium nickel concentration could be written in terms of the pre-equilibrated extractant concentration Kinetic studies were carried out using the rising drop method, reaction orders were determined with respect to the aqueous phase nickel concentration, Ni2+, the aqueous phase sodium concentration, Na + the pH, the organic phase dimer concentration ------ and the organic phase sodium salt concentration ---- In addition, it was found that the extraction kinetics could be explained in terms of an aqueous phase interfacial reaction accompanied by diffusion through the interface. Mass transfer coefficient values were determined indicating extraction rates for metal extraction into HDTMPP were the same order o...

A study has been made of the extraction of sodium into bis (2,4,4 -trimelhylpentyl) phosphinic acid. The following basic constants were measured at 25°C using two-phase titration techniques: the so...

Mono-dispersed semiconductor ZnS hollow spheres with the diameter of 300–500 nm and the shell thickness of about 100–150 nm have been synthesized successfully by solvothermal method from ethanol solution in the presence of a special surfactant—quaternary ammonium salt of 2-undecyl-1-dithioureido-ethyl-imidazoline (SUDEI) made in our lab. The mono-dispersed ZnS hollow spheres are characterized by XRD, size distribution investment, UV–vis, TEM, and SEM, respectively. The UV–vis measurement indicates that there is a broad absorption at 210–280 nm, which is likely to be caused by “hollow-effect.” A growth mechanism of ZnS hollow spheres has also been put forward and discussed.

Silver-coated poly(methyl acrylic acid) (PSA) core-shell colloid particles were prepared by an in situ chemical reduction method. Crystalline silver/titania composite hollow spheres were obtained by coating the as-prepared PSA/silver particles with an amorphous titania layer and subsequently calcining in Ar atmosphere. SEM and TEM investigation indicated that the size of the as-prepared PSA/silver and PSA/silver/TiO(2) core-shell particles and silver/titania composite hollow particles was fairly uniform and the wall thickness of the hollow spheres was in the range of 40-80 nm. UV-vis absorption spectra were recorded to investigate their optical properties.

A series of Bi2S3 microstructures, including crepe paper flower-like structures, multibranched nanobelts, actinomorphic-flower-like 2-D assembled nanowire arrays, straw-tied-like nanowire arrays, and nanowires have been synthesized through facile decomposition of the as-formed bismuth diethyldithiocarbamate (Bi-DDTC) single-source precursor in its precursor solution. The morphologies and concentration and site of structure defects of the Bi2S3 microstructures can be controlled by manipulating the concentration of Bi/DDTC and the reaction time. Possible growth mechanisms involving defect effects, oriented attachment and folding–splitting–attaching growth were proposed, which were responsible for morphology and structure evolution of various Bi2S3 microstructures.