Permethrin, a poorly water-soluble synthetic pesticide belonging to the pyrethroid family, was formulated into water-dispersive nanometric form by rapid evaporation of pesticide loaded oil-in-water microemulsion. The mean hydrodynamic diameter of Nanopermethrin was found to be 199.01 ± 1.4 nm. The efficacy of the Nanopermethrin was comparatively investigated with its bulk form against 2-3 days old adult mosquitoes by WHO cone bioassay for 60 min. The median knockdown concentration of Culex tritaeniorhynchus, Culex quinquefasciatus and Aedes albopictus were found to be 7.20 × 10(4), 7.53 × 10(4), 0.42 × 10(3) mg/L for Bulk permethrin, and 0.98 × 10(4), 1.17 × 10(4), 0.05 × 10(3) mg/L for Nanopermethrin, respectively. The obtained results extrapolate the improved efficacy of Nanopermethrin even at low-level concentrations. Hence, the formulated Nanopermethrin will serve as an effective alternative pesticide in controlling the mosquito population with reduced environmental toxicity.[on SciFinder (R)]
Transparent conductive films composed of CuS were formed by wet deposition on PET at room temp. followed by annealing at 100° for 1 h. The resistance of the films was tuned by doping with In3+. A decrease of over an order of magnitude of the sheet resistance was obtained, from 1721 Ω sq-1 for undoped CuS film to 109 Ω sq-1 for In3+ doped. Transparency of the conducting films could be tuned by an appropriate selection of reaction time and In3+ concn. Films contg. 10 mol% of In3+ ions after a reaction duration of 24 h have a sheet resistance of ∼270 Ω sq-1 and a transparency of ∼80%. The fabricated films are characterized by excellent adhesion to the PET substrate and are suitable for use as transparent conducting electrodes (TCE) in flexible electroluminescent (EL) devices. [on SciFinder(R)]
The use of printing to produce 2D arrays is well established, and should be relatively facile to adapt for the purpose of printing biomaterials; however, very few studies have been published using enzyme solns. as inks. Among the printing technologies, inkjet printing is highly suitable for printing biomaterials and specifically enzymes, as it offers many advantages. Formulation of the inkjet inks is relatively simple and can be adjusted to a variety of biomaterials, while providing nonharmful environment to the enzymes. Here we demonstrate the applicability of inkjet printing for patterning multiple enzymes in a predefined array in a very straightforward, noncontact method. Specifically, various arrays of the enzymes glucose oxidase (GOx), invertase (INV) and horseradish peroxidase (HP) were printed on aminated glass surfaces, followed by immobilization using glutardialdehyde after printing. Scanning electrochem. microscopy (SECM) was used for imaging the printed patterns and to ascertain the enzyme activity. The successful formation of 2D arrays consisting of enzymes was explored as a means of developing the first surface confined enzyme based logic gates. Principally, XOR and AND gates, each consisting of two enzymes as the Boolean operators, were assembled, and their operation was studied by SECM. [on SciFinder(R)]
This work describes a novel supercapacitor electrode based on a glass fiber felt substrate, single-walled carbon nanotube (SWCNT) and metal oxide layers (RuO2 or MnO2). It is fabricated by the repeated and alternate deposition of SWCNTs and metal oxides via dipping and electrodeposition, resp., to achieve three-dimensional layered hierarchical structured supercapacitor electrodes. The results show that the layered structured electrodes fabricated by alternating deposition of SWCNTs and metal oxides have higher capacitance as compared with the bulk deposited samples, which are fabricated by deposition of SWCNTs followed by metal oxides. The best configuration studied in this work shows specific capacitance of 72 and 98 F/g for the SWCNT-MnO2 and SWCNT-RuO2, resp., whereas the corresponding areal capacitances are 0.07 and 0.09 F/cm2. This three-dimensional porous electrode structure design combines the high mech. stability of the felt substrate with the high cond. and sp. surface area of SWCNTs, and the high capacitance of metal oxides. This will add immensely to the research and development of wearable lightwt. electronics in harsh environments. [on SciFinder(R)]
The formation of 3D objects composed of shape memory polymers for flexible electronics is described. Layer-by-layer photopolymerization of methacrylated semicrystalline molten macromonomers by a 3D digital light processing printer enables rapid fabrication of complex objects and imparts shape memory functionality for electrical circuits.
This work reports on the prepn. of semitransparent perovskite solar cells. The cells transparency is achieved through a unique wet deposition technique that creates perovskite grids with various dimensions. The perovskite grid is deposited on a mesoporous TiO2 layer, followed by hole transport material deposition and evapn. of a semitransparent gold film. Control of the transparency of the solar cells is achieved by changing the perovskite soln. concn. and the mesh openings. The semitransparent cells demonstrate 20-70% transparency with a power conversion efficiency of 5% at 20% transparency. This is the first demonstration of the possibility to create a controlled perovskite pattern using a direct mesh-assisted assembly deposition method for fabrication of a semitransparent perovskite-based solar cell. [on SciFinder(R)]
Stray light, also known as optical noise, affects the performance of many optical devices. It can be reduced to a tolerable level by well-designed and well-baffled system or/and by using functional black coatings that are fabricated in a complex and costly process. Carbon nanotubes (CNTs) absorb light strongly, making them an ideal candidate for realizing a super black coating. CNT coatings were formed by spraying formulations composed of a silicon binder and low cost multiwalled CNTs on a pre-heated aluminum plate. The diffuse reflectance of the coatings in the VIS range (350-800nm) was in the range of 2.6-5.11%, depending on the MWCNT concentration in the coating. In the NIR range (850-2400nm), the reflectance values were in the range of 4-6.5%, however the dependence on MWCNT concentration was not very significant. Excellent adhesion to the aluminum substrates was achieved, for coatings with CNT concentration below 15%, while still having very low reflectance, even at temperature c
Vanadium dioxide (VO2), with a reversible phase transition near ambient temperature, has been found to be a promising candidate for energy-saving smart windows. However, its use is constrained by its low visible transmission (Tlum) and high transition temperature (τc). In this paper, by codoping tungsten (W) and magnesium (Mg) in VO2, a good combination of low τc (∼35 °C) and high Tlum (81.3%) was achieved. The τc declines with decreasing Mg doping level in Mg/W-codoped samples, which is the opposite effect of doping with only Mg, suggesting a synergistic effect of the two dopants arising from the e− and h+ carrier neutralization. In addition, the band gap of Mg/W-codoped VO2 was gradually widened; this is attributed to the depressed absorption, which enhanced the Tlum. [ABSTRACT FROM AUTHOR]Copyright of Journal of Materials Chemistry C is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
This study presents a method for one step incorporation of lipophilic compounds in hydrophilic nanofibers. By this method nanodroplets of oil and of volatile solvent are entrapped within polymer nanofibers during an electrospinning process. While performing the process with a volatile oil with dissolved lipophilic material, such as the drug celecoxib, nanofiber–nanoparticle composites are formed. The polymer used to form the fibers is a high molecular weight poly(vinyl alcohol) which enables rapid dissolution and release of the incorporated lipophilic material. The resulting celecoxib nanoparticles that are embedded within the nanofiber are amorphous and their average size is in between 21 and 93nm, thus potentially lead to their increased dissolution rate. The preparation of such a solid matrix containing nanodroplets or nanoparticles may be applied as a fast dissolving delivery system for water insoluble materials.
The growing interest in the field of three-dimensional printing has led to great demand for new materials. In this paper we should like to present a new ink for printing porous structures that can be used for embedding various functional materials. The ink is composed of a UV polymerizable oil-in-water emulsion which converts into a solid object upon UV irradiation, and upon evaporation of the aqueous phase, forms a porous structure. The 3D objects with their various porosities, were printed by a Digital Light Processing (DLP) printer. The total surface area of the object can be controlled by changing the emulsion's droplets size and the dispersed phase fraction. The printed 3D porous structures can be used in a variety of applications, and here we show a composite conductive object, made of silver and cross-linked polymer. After the porous object is formed, the pores are filled by vacuum, dipping in a dispersion of silver nanoparticles, followed by chemical sintering at room temperature, which results in conductive percolation paths within the 3D structure. Application of this structure is demonstrated for use as a 3D connector of an electrical circuit. [ABSTRACT FROM AUTHOR]Copyright of Journal of Materials Chemistry C is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Intraoperative ureter identification can assist in the prevention of ureteral injury and consequently improve surgery outcomes. Our aim was to take advantage of the altered pharmacokinetics of liposomal indocyanine green (ICG), the only FDA-approved near-infrared (NIR) dye, for imaging of ureters during surgeries. ICG was passively adsorbed to liposomes. NIR whole mice body and isolated tissue imaging were used to study liposomal ICG properties vs. free ICG. In vivo, the urinary bladder could be clearly observed in most of the liposome-treated mice. Liposomal encapsulation of ICG enhanced ureteral emission up to 1.9 fold compared to free ICG (P<0.01). Increase in liposomal micropolarity and microviscosity and differential scanning calorimetry supported ICG localization within the liposomal bilayer. Our findings suggest that liposomal ICG could be utilized for ureteral imaging intra-operatively, thus potentially improving surgical outcomes.
The patterning of various 2D and 3D substrates is accomplished using a new method, reactive transfer printing, combined with a self-reducing copper precursor. The ink composed of the metal precursor is printed on a donor substrate; during its decomposition, the metal is transferred to an acceptor substrate. This process is demonstrated with copper formate as the precursor, forming a copper pattern with excellent conductivity (50% that of bulk copper).
Highly conductive copper patterns on low-cost flexible substrates are obtained by inkjet printing a metal complex based ink. Upon heating the ink, the soluble complex, which is composed of copper formate and 2-amino-2-methyl-1-propanol, decomposes under nitrogen at 140 °C and is converted to pure metallic copper. The decomposition process of the complex is investigated and a suggested mechanism is presented. The ink is stable in air for prolonged periods, with no sedimentation or oxidation problems, which are usually encountered in copper nanoparticle based inks.
This is a review on recent developments in the field of transparent conductive coatings (TCCs) for ITO replacement. The review describes the basic properties of conductive nanomaterials suitable for fabrication of such TCCs (metallic nanoparticles and nanowires, carbon nanotubes and graphene sheets), various methods of patterning the metal nanoparticles with formation of conductive transparent metallic grids, honeycomb structures and 2D arrays of interconnected rings as well as fabrication of TCCs based on graphene and carbon nanotubes. Applications of TCCs in electronic and optoelectronic devices, such as solar cells, electroluminescent and electrochromic devices, touch screens and displays, and transparent EMI shielders, are discussed. [on SciFinder(R)]
Printed electrochromic flexible films were obtained by combining transparent silver grid electrodes formed by self-assembly and inkjet printed WO3 nanoparticles. Concd. dispersions of WO3 nanoparticles were inkjet printed on transparent plastic silver grid electrodes with a high transparency of 83% in the spectral range of 400-800 nm, and a low sheet resistance in the range of 1-5 Ω sq-1. These electrodes were used for electrochromic applications for the first time. The resultant patterned nanostructured electrochromic films maintained their coloring and bleaching performance after bending of the flexible films. [on SciFinder(R)]
Ensuring drug loading efficiency and consistency is one of the most critical stages in engineering drug delivery vectors based on porous materials. Here we propose a technique to significantly enhance the efficiency of loading by employing simple and widely available methods: applying low pressure with and without centrifugation. Our results point toward the advantages the proposed method over the passive loading, especially where the size difference of loaded materials and the pore size of the porous silicon particles is smaller, an increase up to 20-fold can be observed. The technique described in the study can be used for efficient and reproducible loading of porous materials with therapeutic molecules, nanoparticles and contrast imaging agents for biomedical application.;