High Performance Ultraviolet Photodetector Fabricated with ZnO Nanoparticles-graphene Hybrid Structures

Ultraviolet （UV） photodetector constructed by ZnO material has attracted intense research and commercial interest. However, its photoresistivity and photoresonse are still unsatisfied. Herein, we report a novel method to assemble ZnO nanoparticles （NPs） onto the reduced graphite oxide （RGO） sheet by simple hydrothermal process without any surfactant. It is found that the high-quality crystallized ZnO NPs with the average diameter of 5 nm are well dispersed on the RGO surface, and the density of ZnO NPs can be readily controlled by the concentration of the precursor. The photodetector fabricated with this ZnO NPs- RGO hybrid structure demonstrates an excellent photoresponse for the UV irradiation. The results make this hybrid especially suitable as a novel material for the design and fabrication of high performance UV photodector.

Novel Hybrid Nanoparticles of Vanadium Nitride/Porous Carbon as an Anode Material for Symmetrical Supercapacitor

Hybrid materials of vanadium nitride and porous carbon nanoparticles(VN/PCNPs) were fabricated by a facile pyrolysis process of vanadium pentoxide(V_2O_5) xerogel and melamine at relatively low temperature of 800 °C for supercapacitor application. The effects of the feed ratio of V_2O_5 to melamine(r), and nitrogen flow rate on the microstructure and electrochemical performance were also investigated. It was found that the size of the as-synthesized nanoparticles is about 20 nm. Both r value and N_2 flow rate have enormous impacts on morphology and microstructure of the nanoparticle, which correspondingly determined the electrochemical performance of the material. The VN/C hybrid nanoparticles exhibited high capacitive properties, and a maximum specific capacitance of 255.0 Fg^(-1) was achieved at a current density of 1.0 Ag^(-1) in 2 M KOH aqueous electrolyte and the potential range from 0 to -1.15 V. In addition,symmetrical supercapacitor fabricated with the as-synthesized VN/PCNPs presents a high specific capacitance of 43.5 F g^(-1) at 0.5 A g^(-1) based on the entire cell, and an energy density of 8.0 Wh kg^(-1) when the power density was 575 W kg^(-1). Even when the power density increased to 2831.5 W kg^(-1), the energy density still remained 6.1 Wh kg^(-1).

A Simple Approach to Fabricate CdS-SiO_2 Hybrid Microspheres by Producing CdS Nanoparticles on the Surface of Thiolated SiO_2 Microspheres

We have developed a simple synthetic method to prepare the hybrid microspheres of CdS nanoparticles on the surface of silica microspheres modified by（3-mercaptopropyl） trimethoxysilane（MPS）. The--SH groups of MPS can bind with the Cd^2＋ ions on the surface of SiO2. When thioacetamide releases H2S, the nanosized CdS particles（ 1-6 nm） will successfully be generated on the silica surface under the experimental conditions. The size of the CdS nanoparticles was found to be related to the concentration of Cd^2 ＋ feed and the size of silica spheres, the higher the concentration of Cd^2＋ and the larger of silica microspheres, the bigger the size of CdS nanoparticles. Techniques including UV, PL, TEM and XPS were used to characterize the CdS-SiO2 hybrid microspheres.

Multidimensional Hybrid Architecture Encapsulating Cobalt Oxide Nanoparticles into Carbon Nanotube Branched Nitrogen-Doped Reduced Graphene Oxide Networks for Lithium–Sulfur Batteries

Lithium–sulfur batteries(LSBs)are regarded as promising candidates for the next-generation energy storage devices owing to their high-theoretical capacity(1675 mAh g^(−1))and affordable cost.However,several limitations of LSBs such as the lithium polysulfide shuttle,large volume expansion,and low electrical conductivity of sulfur need to be resolved for practical applications.To address these limitations,herein,a multidimensional architectured hybrid(Co@CNT/nG),where Co_(3)O_(4) nanoparticles are encapsulated into threedimensional(3D)porous N-doped reduced graphene oxide interconnected with carbon nanotube(CNT)branches,is synthesized through a simple pyrolysis method.The synergistic effect achieved through the homogeneously distributed and encapsulated Co_(3)O_(4) nanoparticles,the interconnected CNT branches,and the 3D hierarchical porous structure and N-doping of Co@CNT/nG significantly suppresses the shuttle effect of lithium polysulfides and enhances the conversion redox kinetics for the improved sulfur utilization.We validate this effect through various measurements including symmetric cells,Li_(2)S nucleation,shuttle currents,Tafel slopes,diffusion coefficients,and post-mortem analyses.Importantly,Co@CNT/nG-70S-based LSB cells achieve a high-specific capacity of 1193.1 mAh g^(−1) at 0.1 C and a low capacity decay rate of 0.030%per cycle for 700 cycles at 5 C,delivering a high areal capacity of 5.62 mAh cm^(−2) even with a loading of 6.5 mg cm^(−2).

Exploring the potential of functional polymer-lipid hybrid nanoparticles for enhanced oral delivery of paclitaxel

Most biopharmaceutics classification system(BCS)class IV drugs,with poor solubility and inferior permeability,are also substrates of P-glycoprotein(P-gp)and cytochrome P450(CYP450),leading to their low oral bioavailability.The objective of this study is to explore the potential of using functional polymer-lipid hybrid nanoparticles(PLHNs)to enhance the oral absorption of BCS IV drugs.In this paper,taking paclitaxel(PTX)as a drug model,PTX-loaded PLHNs were prepared by a self-assembly method.Chitosan was selected to modify the PLHN to enhance its mucoadhesion and stability.Three P-gp inhibitors(D-α-tocopherol polyethylene glycol 1000 succinate,pluronic P123 and Solutol RHS15)were incorporated into selected PLHNs,and a CYP450 inhibitor(the extract of VBRB,BC0)was utilized to jointly promote the drug absorption.Properties of all the PLHNs were characterized systemically,including particle size,zeta potential,encapsulation efficiency,morphology,stability,in vitro drug release,mucoadhesion,in situ intestinal permeability and in vivo systemic exposure.It was found mucoadhesion of the CS-modified PLHNs was the strongest among all the formulations tested,with absolute bioavailability 21.95%.P-gp and CYP450 inhibitors incorporation further improved the oral bioavailability of PTX to 42.60%,8-fold increase compared with that of PTX itself(4.75%).Taken together,our study might shed light on constructing multifunctional PLHNs based on drug delivery barriers for better oral absorption,especially for BCS IV drugs.

NOVEL HYBRID GENE VECTOR STABILIZED BY CROSS-LINKING WITH GOLD NANOPARTICLES

Enhanced stability of polyplexes in physiological condition was an important prerequisite for successful systemic gene delivery.Herein novel method was reported to develop stable gene vector by nanotechnology.Thiolated polyplexes were constructed and then cross-linked with gold nanoparticles(AuNPs)by gold-thiol interactions.TEM pictures showed that AuNPs were attached to the shell of spherical polyplexes.The hybrid gene vector was stable enough in physiological condition and maintained efficient transfectio...

SYNTHESIS AND CHARACTERIZATION OF STRUCTURALLY WELL-DEFINED POLYMER-INORGANIC HYBRID NANOPARTICLES VIA ATRP

Atom transfer radical polymerization (ATRP) using cuprous chloride/2,2'-bipyridine (bipy) was applied to graft polymerization of styrene on the surface of silica nanoparticles to synthesize polymer-inorganic hybrid nanoparticles, 2-(4Chloromethylphenyl) ethyltriethoxysilane (CTES) was immobilized on the surface of silica nanoparticles through condensation reaction of the silanol groups on silica with triethoxysilane group of CTES. Then ATRP of St was initiated by this surface-modified silica nanoparticles bearing benzyl chloride groups, and formed PSt graft chains on the surface of silica nanoparticles. The thickness of the graft chains increased with reaction time. End group analysis confirmed the occurrence of ATRP. Thermal analysis indicated that thermal stabilization of these resulting hybrid nanoparticles also increases with polymerization conversion. The results above show that this 'grafting from' reaction could be used for the preparation of polymer-inorganic hybrid nanoparticles with controlled structure of the polymer's end groups.

PEO-b-P4VP/Yttrium Hydroxide Hybrid Nanotubes as Supporter for Catalyst Gold Nanoparticles

The adsorption of poly （ethylene oxide）-b-poly（4-vinylpyridine）（PEO-b-P4VP） micelles onto the surface of yttrium hydroxide nanotubes （YNTs） resulted in the hybrid nanotubes with a dense P4VP inner layer and a stretched PEO outer layer surrounding YNTs. The dense P4VP layer was further stabilized by the crosslinking using 1,4-dibromobutane as the crosslinker. Then, the crosslinked hybrid nanotubes （CHNTs） were used as a novel nano supporter for loading the catalyst gold nanoparticles （GNPs） within the crosslinked P4VP layer. The resultant GNPs/CHNTs （GNTs loaded on CHNTs） were applied to catalyze the reduction reaction of p-nitrophenol. The results indicate that this novel nano supporter has advantages such as good dispersity in the suspension, high capacity in loading GNPs （0.87 mmol/g）, high catalytic activity of the loaded GNPs （12.9 μmol-lmin-i）, and good reusability of GNTs/CHNTs.

Carbon nanotube supported PtOx nanoparticles with hybrid chemical states for efficient hydrogen evolution

Efficient electrocatalysts for hydrogen evolution reaction(HER) in alkaline solution are highly required for water splitting.Here we design an ultra-small PtOx nanoparticle with hybrid Pt chemical states on carbon nanotubes as highly efficient alkaline HER catalyst,which shows a low overpotential of 19.4 mV at 10 mA cm^(-2),a high mass activity of 5.56 A mg_(Pt)^(-1) at 0.1 V, and a stable durability for at least 20 h.The HER performance is better than that of the benchmark 20 wt% Pt/C while the Pt content in the catalyst is only about one tenth of that in Pt/C.It also represents one of the best catalysts ever reported for HER in alkaline solution.Synchrotron radiation X-ray absorption spectroscopy reveals that the efficient and stable alkaline HER performance can be attributed to the favorable design of hybrid chemical states of Pt with carbon nanotubes,which exhibits abundant surface Pt-O as active catalytic sites and forms stable Pt-C interfacial interaction to both anchor the NPs and improve the synergistic effect between catalyst and substrate.

Numerically simulated behavior of radiative Fe_(3)O_(4) and multi-walled carbon nanotube hybrid nanoparticle flow in presence of Lorentz force

Free convection in hybrid nanomaterial-saturated permeable media is crucial in various engineering applications.The present study aims to investigate the free convection of an aqueous-based hybrid nanomaterial through a zone under the combined effect of the Lorentz force and radiation.The natural convection of the hybrid nanomaterial is modeled by implementing a control volume finite element method(CVFEM)-based code,whereas Darcy assumptions are used to model the porosity terms in the momentum buoyancy equation involving the average Nusselt number Nu_(ave),flow streamlines,and isotherm profiles.A formula for estimating Nu_(ave) is proposed.The results show that the magnetic force retards the flow,and the fluid tends to attract the magnetic field source.Nu_(ave) is directly correlated with the Rayleigh number and radiation;however,it is indirectly dependent on the Hartmann number.Conduction is the dominant mode at larger Darcy and Hartmann numbers.

Morphology and Electronic Properties of Hybrid Organic-Inorganic System: Ag Nanoparticles Embedded into CuPc Matrix

Materials with a high on-off resistance ratio could become the basis for resistive random-access memory (RRAM). It is assumed that one of RRAM types can be based on hybrid organic-inorganic systems, while particular attention is focused on hybrid systems consisting of metal nanoparticles (NP) embedded in organic matrix (OM). In this investigation we created and studied the hybrid organic-inorganic systems made of metal (Ag) nanoparticles embedded in organic semiconductor material CuPc. The LEED patterns and NEXAFS data demonstrate that the CuPc films deposited on Au(001) substrate are highly ordered and molecular planes lie parallel to the gold surface. The metal atoms were deposited on the outer surface of the organic molecular film and self-assembled into nanoparticles due to surface and bulk diffusion. The properties of nano-composite materials seem to be significantly dependent on the microstructure, i.e. the size, concentration, bulk- and size-distribution of nanoparticles;therefore we have studied by high resolution transmission electron microscopy the evolution of morphology of nano-composite films as a function of nominal metal deposition. The filled and empty electronic states of the hybrid organic-inorganic systems, energy level alignment at interfaces formed between metal nanoparticles and the organic semiconductor CuPc as well as the chemical interaction at the NP/OM interface were studied by UPS, XPS and NEXAFS methods.

Evaluation of Cisplatin-Loaded Polymeric Micelles and Hybrid Nanoparticles Containing Poly(Ethylene Oxide)-Block-Poly(Methacrylic Acid) on Tumor Delivery

Particulate carriers such as polymeric micelles (PMs) and liposomes have been investigated to increase drug accumulation in tumors and reduce distribution to healthy tissues. In this study, we prepared PM and hybrid nanoparticles (HNPs) with poly(ethylene oxide)-block-poly(methacrylic acid) (PEO-b-PMAA) for loading cisplatin, and evaluated cisplatin release, cytotoxicity, and biodistribution in mice. PM composed of PEO-b-PMAA and HNPs composed of egg phosphatidylcholine (EPC)/PEO-b-PMAA at molar ratios of 50/2.8 (HNP-P5) and 50/50 (HNP-P50), respectively, were prepared by a nanoprecipitation method. The sizes of PM, HNP-P5, and HNP-P50 after inclusion of cisplatin were approximately 200, 100, and 55 nm, respectively, and their entrapment efficiencies were approximately 44% - 66%. In the drug-release study, HNP-P5 and HNP-P50 showed reduced release of cisplatin compared with PM. Regarding the cytotoxic assay, HNP-P5 exhibited lower cytotoxicity for mouse Lewis lung carcinoma (LLC) and mouse colon carcinoma Colon 26 cells than PM and HNP-P50. In terms of biodistribution, PM could significantly improve blood circulation and tumor accumulation after intravenous injection into Colon 26 tumor-bearing mice compared with free cisplatin, but HNP-P5 and HNP-P50 did not. EPC in HNPs might be destabilized in the circulation, although it could reduce release of cisplatin in in vitro experiments. This study suggested that polymeric micelles composed of PEO-b-PMAA are a better carrier for cisplatin than hybrid nanoparticles composed of PEO-b-PMAA and EPC.

Morphology and Properties of Hybrid Systems Comprising Gold Nanoparticles in CuPc Matrices

Transmission electron microscopy and surface- and bulk-sensitive spectroscopic methods were used to study the morphology and the electronic structure of a hybrid organic-inorganic system composed of gold nanoparticles （NP＇s） which were distributed in an organic matrix. Au atoms deposited onto a copper phthalocyanine （CuPc） surface diffuse into the organic matrix and self-assemble in well defined NP＇s with metallic properties. No formation of a continuous metallic Au film on top of the CuPc film is observed up to nominal coverages as large as 130 A.

Molecular recognition by gold, silver and copper nanoparticles

The intrinsic physical properties of the noble metal nanoparticles,which are highly sensitive to the nature of their local molecular environment,make such systems ideal for the detection of molecular recognition events.The current review describes the state of the art concerning molecular recognition of Noble metal nanoparticles.In the first part the preparation of such nanoparticles is discussed along with methods of capping and stabilization.A brief discussion of the three common methods of functionalization:Electrostatic adsorption;Chemisorption;Affinity-based coordination is given.In the second section a discussion of the optical and electrical properties of nanoparticles is given to aid the reader in understanding the use of such properties in molecular recognition.In the main section the various types of capping agents for molecular recognition;nucleic acid coatings,protein coatings and molecules from the family of supramolecular chemistry are described along with their numerous applications.Emphasis for the nucleic acids is on complementary oligonucleotide and aptamer recognition.For the proteins the recognition properties of antibodies form the core of the section.With respect to the supramolecular systems the cyclodextrins,calix[n]arenes,dendrimers,crown ethers and the cucurbitales are treated in depth.Finally a short section deals with the possible toxicity of the nanoparticles,a concern in public health.

Photorefractivity in a Bi-functional Polymer Nanocomposites Sensitized by CdS Nanoparticle

We report an organic/inorganic hybridized nanocomposite consisting of a bi-functional poly（N-vinyl）-3-[p-nitrophenylazo]carbazolyl serves as a polymeric charge-transporting and second-order nonliner optical matrix, and CdS nanoparticles as photosensitizers to manifest photorefractive （PR） effect. The unpoled PVNPAK film exhibits a second harmonic generation （SHG） coefficient of 4.7 pm/V due to the possibility of self-alignment of the azo chromophore. Significant enhancement of photoconductivity is noticed with the increase of CdS nanoparticles concentration. The photorefractive property of the polymer nanocomposites were determined by two-beam coupling （TBC） experiment. The TBC gain and diffraction efficiency of 11.89 cm-1 and 3.2% were obtained for PVNPAK/CdS at zero electrical field.

Facile Method for the Synthesis of Copper Nanoparticles Supported on the Organoclay Material

In this study, synthesis of copper nanoparticles was performed using organoclay as a support to stabilize the nanoparticles. Organoclay amount was gradually increased, which had an effect on the morphology of the resultant nanoparticles. Low amount of organoclay added resulted in larger and agglomerated copper nanoparticles whereas increased amount of organoclay gave smaller sized nanoparticles. The hybrid materials were characterized using the SEM and TEM for morphology, XRD and FT-IR spectroscopy for structural elucidation, thermal analysis using TGA and also studying their antibacterial effect on the two well-known gram negative bacteria of E. coli and P. Aeruginosa. The synthesized nanoparticles were found to be crystalline Cu nanoparticles with a mix of CuO. Larger sized copper nanoparticles and agglomerates showed the higher thermal behaviour as compared with smaller nanoparticles with higher organoclay loading. The hybrid showed an improved antibacterial activity as compared with organoclay alone. The hybrid showed the higher antibacterial effect against the P. aeruginosa microorganism as compared with the E. coli microorganism.

Light focusing in linear arranged symmetric nanoparticle trimer on metal film system

Benefiting from the induced image charge on film surface,the nanoparticle aggregating on metal exhibits interesting optical properties.In this work,a linear metal nanoparticle trimer on metal film system has been investigated to explore the novel optical phenomenon.Both the electric field and surface charge distributions demonstrate the light is focused on film greatly by the nanoparticles at two sides,which could be strongly modulated by the wavelength of incident light.And the influence of nanoparticle in middle on this light focusing ability has also been studied here,which is explained by the plasmon hybridization theory.Our finding about light focusing in nanoparticle aggregating on metal film not only enlarges the novel phenomenon of surface plasmon but also has great application prospect in the field of surface-enhanced spectra,surface catalysis,solar cells,water splitting,etc.

Membrane-coated nanoparticles as a biomimetic targeted delivery system for tumour therapy

Drug therapy towards tumours often causes adverse effects because of their non-specific nature.Membrane-coated technology and membrane-coated nanoparticles provide an advanced and promising platform of targeted and safe delivery.By camouflaging the nanoparticles with natural derived or artificially modified cell membranes,the nano-payloads are bestowed with properties from cell membranes such as longer circulation,tumour or inflammation-targeting,immune stimulation,augmenting the performance of traditional therapeutics.In this review,we review the development of membrane coating technology,and summarise the technical details,physicochemical properties,and research status of membrane-coated nanoparticles from different sources in tumour treatment.Finally,we also look forward to the prospects and challenges of transforming membrane coating technology from experiment into clinical use.Taken together,membrane-coated nanoparticles are bound to become one of the most potential anti-tumour strategies in the future.

Inhibition of wax crystallization and asphaltene agglomeration by core-shell polymer@SiO_(2) hybride nano-particles

The gelation of crude oil with high wax and asphaltene content at low temperatures often results in the block of transportation pipeline in Africa. In recent years, it was reported that surface hydrophobicmodified nanoparticles have important applications in crude oil flow modification. In this work, four kinds of core-shell hybride nanoparticles by grafting poly(octadecyl, docosyl acrylate) and poly(acrylate-α-olefin) onto the surface of nano-sized SiO_(2) were synthesized by grafting polymerization method.The chemical structure of nanoparticles was analyzed by Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM) and thermogravimetric analysis(TGA). The rheological behaviors of crude oil and precipitation of asphaltenes in the presence of nanoparticles were studied by measuring the viscose-temperature relationship curve, the cumulative wax precipitation amount, and morphology of waxes and asphaltenes. The results indicate that the docosyl polyacrylate@SiO_(2) nanoparticle(PDA@SiO_(2)) can reduce the cumulative wax precipitation amount of crude oil by 72.8%, decline the viscosity of crude oil by 85.6% at 20℃, reduce the average size of wax crystals by 89.7%, and inhibit the agglomeration of asphaltene by 74.8%. Therefore, the nanoparticles not only adjust the crystalline behaviors of waxes, but also inhibit the agglomeration of asphaltenes. Apparently, core-shell hybride nanoparticles provides more heterogeneous nucleation sites for the crystallization of wax molecules,thus inhibiting the formation of three-dimensional network structure. The core-shell polymer@SiO_(2) hybride nanoparticles are one of promising additives for inhibiting crystallization of waxes and agglomeration of asphaltenes in crude oil.

Photoconductivity of novel poly(N-vinyl)-3-[p-nitrophenylazo]carbazole/CdS-nanoparticle polymer composite

The photoconductive characteristic of the inorganic/organic hybridized polymer system is reported, in which a novel bi-functional photorefractive (PR) poly(N-vinyl)-3-[p-nitrophenylazo]carbazole (PVNPAK) serves as a polymeric charge-transporting and second-order nonliner optical matrix and quantum dots composed of surface passivated cadmium sulfide serve as a charge-generation sensitizer. The hybrid PVNPAK/CdS-nanoparticles polymer composites with different mass ratio of CdS to PVNPAK were prepared. The generation of photocurrent on illumination and photoconductive properties of the PVNPAK/CdS-nanoparticles polymer composites were studied. The results show that the addition of CdS nanoparticle as a photosensitizer can enhance the photoconductivity of the PVNPAK significantly because of the properties of the high quantum efficiency of photosensitization and high charge transport to conducting polymer.