High Refractive Index Films Prepared from Titanium Chloride and Methyl Methacrylate via a Non-Aqueous Sol–Gel Route

Poly(methylmethacrylate)/silica/titania films were prepared via a nonaqueous sol–gel route at ambient temperature, followed by spin-coating and multistep baking. The acrylic monomers used were methyl methacrylate (MMA) and 3-(trimethoxysilyl)propyl methacrylate (MSMA). Silicic acid and titanium(IV) chloride were used as the precursors of the inorganic component. FTIR results indicated the successful bonding between TiO₂ and SiO₂. TEM images suggested the silica/titania particles were well dispersed in the Poly(methyl methacrylate) (PMMA) matrix with the particles size smaller than 40 nm in our study. The refractive index and extinction coefficient were also studied. The refractive index of the hybrid increased with increasing the titania content, and the hybrid films showed high optical transparency in visible region.     

Synthesis of Hybrid Organic-Inorganic Hydrotalcite-Like Materials Intercalated with Duplex Herbicides: The Characterization and Simultaneous Release Properties

In this study, a controlled-release formulation of duplex herbicides, namely, 2,4,5-trichlorophenoxybutyric acid (TBA) and 3,4-dichlorophenoxy-acetic acid (3,4D), was simultaneously embedded into Zn-Al-layered double hydroxides (LDHs). The resulting nanohybrid Zinc-Aluminium-3,4D-TBA (ZADTX) was composed of a well-ordered crystalline layered structure with increasing basal spacing from 8.9 Å to 20.0 Å in the Powder X-ray Diffraction (PXRD) with 3,4D and TBA anions located in the gallery of LDHs with bilayer arrangement. The release of 3,4D and TBA fit the pseudo-second-order model. This duplex nanohybrid possessed a well-controlled release property (53.4% release from TBA and 27.8% release from 3,4D), which was highly effective, requiring the use of a small quantity and, hence, environmentally safer.     

Mesogeneous Catalysts: A New Concept in Nanotechnology

Summary: A novel type of catalysis, neither homogeneous nor heterogeneous, is presented. This new “mesogeneous catalysis” combines the high efficiency characteristic of the homogeneous process with the advantages of the heterogeneous one (i.e., the possibility of removing and reusing the catalyst and obtaining catalyst‐free products). The reactions are performed on the surface of nano‐particles, where catalytic‐active sites have been previously chemically anchored by a short dangling organic chain, thus forming a nanohybrid system.

Methanol produced by the different catalysts, after 60 min.     

Synthesis and characterization of multiwall carbon nanotubes/alumina nanohybrid-supported cobalt catalyst in Fischer-Tropsch synthesis

Multiwall carbon nanotubes (MWNTs) and alumina are combined to give a new type of nanohybrid for Fisher-Tropsch synthesis (FTS) catalyst support. Alumina nano-particles (10 wt%) were introduced directly on functionalized MWNTs by a modified sol-gel method. Microstructure observations show that alumina particles were homogeneously dispersed on the inside and outside of modified MWNTs surfaces. 15 wt% cobalt loading catalysts were prepared with this nanohybrid and γ-alumina as a reference, using a sol-gel technique and wet impregnation method respectively. These catalysts were characterized by TEM, XRD, N₂-adsorption, H₂ chemisorption and TPR. The deposition of cobalt nanoparticles synthesized by sol-gel technique on the MWNTs nanohybrid shift the reduction peaks to a low temperature, indicating higher reducibility for uniform cobalt particles. Nanohybrid also aided in high dispersion of metal clusters and high stability and performance of catalyst. The proposed MWNTs nanohybrid-supported cobalt catalysts showed the improved FTS rate (g_HC/(g_cat·min)), CO conversion (%), and water gas shift rate (WGS)(g_CO2/(g_cat·h)) of 0.012, 52, and 30E-3, respectively, as compared to those of 0.007, 25, and 18E-3, respectively, on the γ-alumina-supported cobalt catalysts with the same Co loading.     

Study on Intercalative Nanohybrid of Cordycepin in Layered Double Hydroxide

A novel negatively charged biomolecule-cordycepin has been intercalated within the gallery spaces of [Mg-Al-NO3]. Results of TEM, PXRD and FF-IR spectroscopy confn-med that cordycepin could be intercalated into [Mg-Al-NO3] intedayers as the charge-compensating species.Initial studies suggest that the new bioinorganic nanocomposite may be used as a novel inorganic reservoir or carder of pharmaceutically active compounds.     

Synthesis and Characterization of Imidacloprid/Hydrotalcite-like Compound Nanohybrids

Hydrotalcite‐like compounds (HTlc) were first modified by sodium dodecyl sulfate (SDS), then the intercalation of imidacloprid (IM) into modified HTlc was carried out in mixed solvent of toluene/ethanol by an evaporating solvent enhanced intercalation method, obtaining IM‐SDS‐HTlc nanohybrids. It was found that the nanohybrids could well control the release of imidacloprid, demonstrating that the nanohybrids are a potential pesticide controlled‐release formulation. The release of imidacloprid from IM‐SDS‐HTlc nanohybrids is dependent on the pH and the presence of electrolyte in release medium. Acidic medium and the presence of electrolytes induce the higher release rate of imidacloprid. The release process of imidacloprid from IM‐SDS‐HTlc nanohybrids can be described by pseudo‐second‐order release kinetics.     

A robust UV–visible light‐driven SBA‐15‐PS/phthalhydrazide nanohybrid material with enhanced photocatalytic activity in the photodegradation of methyl orange

SBA‐15‐PS/phthalhydrazide (PHD) is presented as a new heterogeneous inorganic–organic nanohybrid photocatalyst with high stability, superior recyclability and remarkable performance in the degradation of methyl orange (MO). Distinctive parameters, including photocatalyst and dye concentrations, pH and degradation time, were assessed for MO degradation catalysed by SBA‐15‐PS/PHD. This new heterogeneous nanocatalyst was characterized using Fourier transform infrared and UV–visible spectroscopies, thermogravimetric analysis, scanning and transmission electron microscopies and elemental analysis. Photodegradation of MO of up to 92% under the optimum conditions (photocatalyst = 0.015 g, [MO] = 4 ppm, pH = 2) was accomplished in 25 min using SBA‐15‐PS/PHD. A preliminary kinetic investigation was performed, and pseudo‐first‐order kinetics with a high rate constant (0.068 min^?1) was found for MO degradation. Additional results showed that the photodegradation of MO was increased in the presence of hole scavengers. Therefore a photoreduction mechanism for MO degradation is proposed.     

可见近红外光响应直接Z型异质结光催化剂LaNiO3/CdS的产氢性能

通过冷凝-回流方式制备可见近红外光响应直接Z型LaNiO₃/CdS纳米复合物,在对其进行物理化学表征后将其应用于光解水产氢反应。在可见光照射下,LaNiO₃/CdS光催化剂在5 h的H₂产量达到737 μmol,其H₂产量是CdS的4.3倍(172 μmol)。光电化学测试证实,LaNiO₃/CdS之间异质结的构筑能有效地促进光生载流子在界面的迁移、分离,从而促进其光解水产氢效率和稳定性的提高。同时随着近红外光的引入,其产氢活性提高至996 μmol。在上转换荧光测试中,LaNiO₃在808 nm光激发下在406和628 nm显示出发射荧光,这表明其能在近红外光照射下产生光生载流子,从而进一步提高其光解水产氢效率。     

Dual Amplified Electrochemical Immunosensor for Hepatitis B Virus Surface Antigen Detection Using Hemin/G‐Quadruplex Immobilized onto Fe3O4‐AuNPs or (Hemin‐Amino‐rGO‐Au) Nanohybrid

A sensitive electrochemical immunosensor for Hepatitis B virus surface antigen (HBsAg) detection was fabricated based on hemin/G‐quadruplex interlaced onto Fe₃O₄‐AuNPs or hemin ‐amino‐reduced graphene oxide nanocomposite (H‐amino‐rGO‐Au). G‐quadruplex DNAzyme, which is composed of hemin and guanine‐rich nucleic acid, is an effective signal amplified tool for its outstanding peroxidase activity and Fe₃O₄‐AuNPs or (H‐amino‐rGO‐Au) nanocomposites with quasi‐enzyme activity provide appropriate support for the immobilization of hemin/G‐quadruplex. The target protein was sandwiched between the primary antibody immobilized on the GO and secondary antibody immobilized on the Fe₃O₄‐AuNPs or (H‐amino‐rGO‐Au) nanocomposites and glutaraldehyde was used as linking agent for the immobilization of primary antibody on the surface of GO. Both Fe₃O₄‐AuNPs and H‐amino‐rGO‐Au nanocomposite and also hemin/G‐quadruplex can cooperate the electrocatalytic reduction of H₂O₂ in the presence of methylene blue as mediator. The proposed immunosensor has a wide linear dynamic range of 0.1 pg/ml to 300 pg/ml with a detection limit of 60 fg/ml when Fe₃O₄‐AuNPs was used for immobilization of hemin/G‐quadruplex, while the dynamic range and DL were 0. 1–1000 pg/mL and 10 fg/mL, respectively in the presence of H‐amino‐rGO‐ Au nanocomposite as platform for immobilizing of hemin/G‐quadruplex. The proposed immunosensor was also used for analysis of HBsAg in spiked human serum samples with satisfactory results.     

Thermoresponsive Gold Polymer Nanohybrids with a Tunable Cross‐Linked MEO2MA Polymer Shell

Gold nanoparticles (AuNPs) are functionalized with a thermoresponsive polymer shell of a cross‐linked poly(2‐(2‐methoxyethoxy)ethyl methacrylate) (P(MEO₂MA)). To provide a covalent attachment of the polymer to the NP surface, AuNPs are first modified using butanoic acid to develop the encapsulation with the biocompatible thermoresponsive polymer formed by free‐radical precipitation polymerization. Both the MEO₂MA concentration and the shell cross‐linking density can be varied and, in turn, the thickness and the shells' free volume can be fine‐tuned. By downscaling the size of the polymeric shell, the lower critical solution temperature (LCST) is decreased. The LCST in the nanohybrids changes from 19.1 to 25.6 °C when increasing the MEO₂MA content; it reaches almost 26 °C for P(MEO₂MA) (bulk). The maximum decrease in the volume of the nanohybrids is around 40%, resulting in a modification of the light scattering properties of the system and causing a change in the turbidity of the gel network. The sizes of the nanohybrids are characterized using both transmission electron microscopy and dynamic light scattering measurements. Optical properties of the colloidal systems are determined using the derived count rate measurements as an alternative to absorbance or transmittance measurements, confirming the colloidal stability of the nanohybrid systems.