Tunable High Refractive Index Polymer Hybrid and Polymer-Inorganic Nanocomposite Coatings.

Atomized spray plasma deposition (ASPD) provides a single-step, low-temperature, and dry approach for the preparation of high refractive index hybrid polymer or polymer-inorganic nanocomposite coatings. Refractive indices as high as 1.936 at 635 nm wavelength have been obtained for ASPD 4-bromostyrene/toluene-TiO nanocomposite layers containing low titania loadings.

Bioinspired and eco-friendly high efficacy cinnamaldehyde antibacterial surfaces.

Antimicrobial essential oils are incorporated into mussel-inspired and natural plant polyphenol coatings as part of a single-step fabrication process. Polydopamine-cinnamaldehyde, polyethyleneimine-cinnamaldehyde, and tannic acid-cinnamaldehyde coatings exhibit strong antibacterial activities against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus (with the polydopamine- and tannic acid-based systems displaying log Reduction = 8). Cinnamaldehyde impregnation into porous non-woven polypropylene cloth, polytetrafluoroethylene membrane, and knitted cotton cloth also gives rise to high levels of antibacterial activity (log Reduction = 8).

Capture and Release Recyclable Dimethylaminomethyl-Calixarene Functional Cloths for Point-of-Use Removal of Highly Toxic Chromium Water Pollutants.

Chromium(VI) contamination of drinking water arises from industrial activity wherever there is a lack of environmental legislation enforcement regarding the removal of such pollutants. Although it is possible to remove such harmful metal ions from drinking water through large-scale facilities, there currently exists no safe and simple way to filter chromium(VI) oxoanions at the point of use (which is potentially safer and necessary in remote locations or humanitarian scenarios). High-surface-area cloth substrates have been functionalized with calixarene molecules for the selective capture of aqueous chromium(VI) oxoanions in the presence of structurally similar anions.

Ultra-high selectivity pulsed plasmachemical deposition reaction pathways.

Glycidyl methacrylate pulsed plasmas have been investigated using time-resolved in situ mass spectrometry. At low pulsed plasma duty cycles, monomer fragmentation leading to the formation of polymerisation initiator species occurs within each short electrical discharge pulse (t = microseconds timescale). This is followed by conventional step-wise monomer addition polymerisation occurring during the subsequent extended off-period (t = milliseconds timescale), culminating in the growth of well-defined poly(glycidyl methacrylate) chains.

Substrate-Independent Epitaxial Growth of the Metal-Organic Framework MOF-508a.

Plasmachemical deposition is a substrate-independent method for the conformal surface functionalization of solid substrates. Structurally well-defined pulsed plasma deposited poly(1-allylimidazole) layers provide surface imidazole linker groups for the directed liquid-phase epitaxial (layer-by-layer) growth of metal-organic frameworks (MOFs) at room temperature. For the case of microporous [Zn (benzene-1,4-dicarboxylate)-(4,4'-bipyridine)] (MOF-508), the MOF-508a polymorph containing two interpenetrating crystal lattice frameworks undergoes orientated Volmer-Weber growth and displays CO gas capture behavior at atmospheric concentrations in proportion to the number of epitaxially grown MOF-508 layers.

Plasmachemical Double Click Thiol-ene Reactions for Wet Electrical Barrier.

Click thiol-ene chemistry is demonstrated for the reaction of thiol containing molecules with surface alkene bonds during electrical discharge activation. This plasmachemical reaction mechanism is shown to be 2-fold for allyl mercaptan (an alkene and thiol group containing precursor), comprising self-cross-linked nanolayer deposition in tandem with interfacial cross-linking to the surface alkene bonds of a polyisoprene base layer. A synergistic multilayer structure is attained which displays high wet electrical barrier performance during immersion in water.

Bioinspired Breathable Architecture for Water Harvesting.

Thuja plicata is a coniferous tree which displays remarkable water channelling properties. In this article, an easily fabricated mesh inspired by the hierarchical macro surface structure of Thuja plicata branchlets is described which emulates this efficient water collection behaviour. The key parameters are shown to be the pore size, pore angle, mesh rotation, tilt angle (branch droop) and layering (branch overlap).

Ultrafast oleophobic-hydrophilic switching surfaces for antifogging, self-cleaning, and oil-water separation.

Smooth copolymer-fluorosurfactant complex film surfaces are found to exhibit fast oleophobic-hydrophilic switching behavior. Equilibration of the high oil contact angle (hexadecane = 80°) and low water contact angle (<10°) values occurs within 10 s of droplet impact. These optically transparent surfaces display excellent antifogging and self-cleaning properties.

Combining plasmachemical emulsion-templating with ATRP to create macroporous lipophilic surfaces.

Well-defined alkyl chain side group polymer brushes have been tethered onto high surface area macroporous pulsed plasmachemical emulsion-templated poly(vinylbenzyl chloride) initiator layers (typically 600-700 m2 g(-1)) using atom transfer radical polymerisation (ATRP). Immobilisation of phospholipids onto these bioactive surfaces is found to occur through interdigitation, and the efficacy of lipid binding is governed by the alkyl side group chain length of the polymer brushes.

Super-adhesive polymer-silica nanocomposite layers.

Atomized spray plasma deposition (ASPD) using a precursor mixture of 2-hydroxyethyl methacrylate and methacryloyl-functionalized 15 nm silica nanoparticles leads to the formation of poly(2-hydroxyethyl methacrylate)-silica nanocomposite layers. The direct application of these coatings to overlapping glass-glass joints gives rise to excellent in situ adhesion reaching 84 MPa shear bond strength and 6 GPa shear modulus prior to the onset of adherent (bulk glass) failure. This significant enhancement in interfacial adhesion arises due to the silica nanoparticle surface methacryloyl groups enhancing cross-linking throughout the nanocomposite layer.

Oxidative atomized spray deposition of electrically conductive poly(3,4-ethylenedioxythiophene).

Atomized spray deposition of 3,4-ethylenedioxythiophene monomer in the presence of triflic anhydride vapour yields electrically conducting poly(3,4-ethylenedioxythiophene) layers.

Determination of major viral and sub viral pathogens incidence in apple orchards in himachal pradesh.

Apple is the major commercial horticulture crop in Himachal Pradesh and other hill states of Jammu & Kashmir, Uttarakhand and some parts of Northeastern states of India. In order to gather data on health status and incidence of virus and virus-like pathogens in apple orchards, survey was conducted in the month of June and September, 2010 in Hatkoti, Rohru, Kuthara, Jubbal and Khadapathar areas of major apple producing Shimla district of Himachal Pradesh. A total of 250 samples were collected and analyzed by DAS-ELISA, NASH and RT-PCR.

Ion- and electron-conducting platinum-polymer nanocomposite thin films.

Non-equilibrium plasmachemical deposition using platinum(II) hexafluoroacetylacetonate precursor leads to the single-step formation of nanocomposite layers comprising an organic host matrix embedded with metal particles of size less than 5 nm. These multifunctional nanocomposite films are found to display both ionic and electronic conductivities.

Superhydrophobic hierarchical honeycomb surfaces.

Two-dimensional hexagonally ordered honeycomb surfaces have been created by solvent casting polybutadiene films under controlled humidity. Subsequent CF(4) plasmachemical fluorination introduces cross-linking and surface texturing, leading to hierarchical surfaces with roughness on both the 10 μm (honeycomb) and micrometer (texturing) length scales. For microliter droplets, these display high water contact angle values (>170°) in combination with low contact angle hysteresis (i.

Highly ion-conducting poly(ionic liquid) layers.

Highly ion-conducting poly(ionic liquid) thin films have been prepared in the absence of solvents utilizing a simple 2-step approach comprising pulsed plasmachemical deposition of 1-allylimidazole followed by vapour-phase quaternization with 1-bromobutane.

Pulsed plasmachemical deposition of highly proton conducting composite sulfonic acid-carboxylic acid films.

Graft polymerization of sulfonic acid monomers onto structurally well-defined pulsed plasma poly(maleic anhydride) layers yields a composite carboxylic acid-sulfonic acid network. These bifunctional films are shown to exhibit high proton conductivity (125 mS cm(-1)) as well as good stability in water.

Tailoring the density of surface-tethered bottlebrushes.

Surface-tethered bottlebrushes have been prepared by ATRP grafting of the macroinitiator brush backbone onto plasmachemical-deposited poly(vinylbenzyl chloride) initiator nanofilms followed by ATRP growth of the side chains (bristles). The surface density of bottlebrushes can be precisely tailored by varying the plasmachemical deposition parameters employed for producing the poly(vinylbenzyl chloride) initiator nanolayers. Lateral force scanning probe microscopy has shown that poly(glycidyl methacrylate)-graft-poly(sodium styrene sulfonate) bottlebrush-decorated surfaces give rise to an enhancement in lubrication.

Impact of picoliter droplets on superhydrophobic surfaces with ultralow spreading ratios.

The impact of picoliter-sized water droplets on superhydrophobic CF(4) plasma fluorinated polybutadiene surfaces is investigated with high-speed imaging. Variation of the surface topography by plasmachemical modification enables the dynamics of wetting to be precisely controlled. Final spreading ratios as low as 0.

Controlled fragrant molecule release from surface-tethered cyclodextrin host-guest inclusion complexes.

β-cyclodextrin barrels can be tethered to solid surfaces using the Williamson ether synthesis reaction via an intermediate pulsed plasma deposited poly(4-vinylbenzyl chloride) linker layer. The loading and release of perfume molecules through host-guest inclusion complex formation with surface tethered β-cyclodextrin has been followed by infrared spectroscopy and quartz crystal microbalance measurements. Fragrance release lasts for several months and can be easily recharged.

A substrate-independent lift-off approach for patterning functional surfaces.

A lift-off method for creating multifunctional patterned surfaces has been devised. It entails consecutive pulsed plasmachemical deposition of a reactive bottom layer and a protective top release layer. By way of example, a bottom/top layer combination comprising pulsed plasma deposited poly(glycidyl methacrylate)/poly(pentafluorostyrene) has been shown to display selective adhesive lift-off of the latter.

Three-dimensional hierarchical structures for fog harvesting.

Conventional fog-harvesting mechanisms are effectively pseudo-2D surface phenomena in terms of water droplet-plant interactions. In the case of the Cotula fallax plant, a unique hierarchical 3D arrangement formed by its leaves and the fine hairs covering them has been found to underpin the collection and retention of water droplets on the foliage for extended periods of time. The mechanisms of water capture and release as a function of the surface 3D structure and chemistry have been identified.

Surface actuation of smart nanoshutters.

Patterned polymer brush surfaces have been fabricated using the molecular scratchcard lithography technique, where a functional top nanolayer (acting also as a resist) is selectively removed using a scanning probe tip to expose underlying atom-transfer radical polymerization (ATRP) initiator sites. The lateral spreading of grafted polymer brush patterns across the adjacent functional resist surface can be reversibly actuated via solvent exposure. Effectively, this methodology provides a means for hiding/unveiling functional surfaces on the nanoscale.

A substrate-independent approach for bactericidal surfaces.

Existing methods for imparting antibacterial performance to solid surfaces tend to either be substrate-specific or rely upon leaching modes of action that cause ecological damage. An alternative approach is outlined comprising plasmachemical functionalization of solid surfaces with poly(4-vinyl pyridine) moieties and their subsequent activation (quaternization) with bromobutane to yield bactericidal activity. These bioactive surfaces can be applied to a host of different substrate materials and are easily regenerated by rinsing in water.

Rewritable glycochips.

We describe microarraying of carbohydrates for protein screening using either disulfide bridge or Schiff base imine immobilization chemistries on plasmachemical deposited functional nanolayers. The commonly observed issue of nonspecific background binding of proteins is overcome by spotting carbohydrates through a protein-resistant overlayer yielding spatially localized interaction with a reactive functional underlayer.

Mimicking a Stenocara beetle's back for microcondensation using plasmachemical patterned superhydrophobic-superhydrophilic surfaces.

A simple two-step plasmachemical methodology is outlined for the fabrication of microcondensor surfaces. This comprises the creation of a superhydrophobic background followed by pulsed plasma deposition of a hydrophilic polymer array. Microcondensation efficiency has been explored in terms of the chemical nature of the hydrophilic pixels and their dimensions.