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-TiO2 nanocomposite layers containing low titania loadings. Thin films with any desired refractive index up to 1.936 can be easily deposited onto a variety of substrates by varying the precursor mixture composition. ASPD overcomes disadvantages commonly associated with alternative fabrication methods for depositing high refractive index coatings (elevated temperatures, wet processes, UV curing steps, and much greater inorganic 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 log10 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 (log10 Reduction = 8). No loss in antibacterial efficacy is observed for non-woven polypropylene cloth impregnated with cinnamaldehyde over 17 recycle tests.

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. This is accomplished by pulsed plasmachemical deposition of a linker layer and subsequent functionalization with dimethylaminomethyl-calixarene (5,11,17,23-tetrakis[(dimethylamino)methyl]-25,26,27,28-tetrahydroxycalix[4]arene). Chromium(VI) oxoanions are captured by simply passing polluted water through the functionalized cloth, while other ions not harmful/beneficial to human health remain in the water. These cloth filters are simple to use, highly selective, and easily recyclable-thus making them attractive for point-of-use application in geographic regions lacking appropriate wastewater treatment plants or flawed environmental monitoring systems. Chromium(VI) pollutants have been successfully removed from real-world contaminated industrial wastewater streams using the dimethylaminomethyl-calixarene functionalized cloths.

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 (ton = microseconds timescale). This is followed by conventional step-wise monomer addition polymerisation occurring during the subsequent extended off-period (toff = milliseconds timescale), culminating in the growth of well-defined poly(glycidyl methacrylate) chains. Key attributes associated with this high selectivity pulsed plasmachemical functional thin film synthesis approach are the absence of the requirement for any additional chemicals (catalyst, solvent, etc.) in combination with very low power consumption (mW) and ambient temperature.

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). Envisaged societal applications include water harvesting and low cost breathable architecture for developing countries.

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.

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.

Diels-Alder chemistry on alkene functionalized films.

A substrate-independent method has been devised for ring formation at solid surfaces. This entails the aminolysis reaction of allylamine with maleic anhydride pulsed plasma polymer films to yield terminal alkene groups at the surface. Subsequent exposure to 1,3-cyclohexadiene leads to a Diels-Alder type (4 + 2) cycloaddition reaction to give a mixture of endo- and exo-bicyclo[2.2.2]oct-2-ene rings.

Diels-Alder chemistry at furan ring functionalized solid surfaces.

A substrate-independent method for Diels-Alder chemistry at solid surfaces is described for the first time.