Published in The Journal of Physical Chemistry A, 2015
we present Fourier transform infrared spectroscopic studies of the 193 nm photoinduced chemistry of nitric oxide (NO) isolated in solid pH2 over the 1.8 to 4.3 K temperature range. Upon short-term in situ irradiation the NO readily undergoes photolysis to yield HNO, NOH, NH, NH3, H2O, and H atoms. Read more
Published in AIP advances, 2017
In this study we use dielectric constants of three different molecular ices in the infrared region to evaluate four different model curves that are generally used for fitting optical constants: (1) the classical damped harmonic oscillator, (2) Voigt line shape, (3) Fourier series, and (4) the Triangular basis. Read more
Published in Physical Chemistry Chemical Physics, 2017
In this work we present kinetic studies of the 193 nm photo-induced chemistry of methanol (CH3OH) isolated in solid pH2. Short-term irradiation of CH3OH at 1.8 K readily produces CH2O and CO which we detect using FTIR spectroscopy. The in situ photochemistry also produces CH3O and H atoms which we can infer from the post-photolysis reaction kinetics that display significant CH2OH growth. Read more
Published in ACS Earth and Space Chemistry, 2018
Acetonitrile (CH3CN) and water (H2O) ice particles were generated within a collisional cooling cell coupled to the Australian Synchrotron light source. The evolution of the aerosols was tracked by infrared spectroscopy compiled over the 4000–50 cm–1 region. Gas pressure and temperature conditions were varied to replicate the lower altitudes of the Titan atmosphere allowing for comparison to far-infrared features detected by the Cassini–Huygens spacecraft. Read more
Published in ACS Earth and Space Chemistry, 2018
Fourier transform infrared spectra of formic acid aerosol particles in situ generated in a collisional cooling cell at temperatures ranging between 90 and 210 K are recorded in the mid-infrared and THz/far-infrared regions. Infrared spectroscopic features are used to identify the formic acid dimer above 200 K, the crystalline β1 phase in the 110–200 K temperature range, and amorphous solid formic acid at ∼90 K. Read more
Published in Progress in Organic Coatings, 2019
We report the preparation of a composite suspension coating from biocompatible carnauba wax and polydimethylsiloxane, and demonstrate its superhydrophobicity and resistance to water impact. The superhydrophobicity and mechanical stability of the coated surfaces can be controlled by adjusting the concentrations of constituent materials. Read more
Published in Journal of Coatings Technology and Research, 2020
we prepare a fluorine-free superhydrophobic coating from hydrophobic SiO2 nanoparticles that can be easily applied to common fabrics by simply spray coating, leading to superhydrophobic fabrics with a water contact angle of 172° and a sliding angle of 3°. The process to achieve extreme water repellency is simple and only involves a single step, and there is no need for further processes like annealing or heat treatment. Read more
Published in ACS Nano, 2020
We demonstrate high-resolution additive jet printing of end-functional polymers to serve as templates for directed self-assembly of nanoparticles into architectures with substantial plasmonic activity. The intriguing aspect of this work is the ability to form patterns of end-grafted poly(ethylene glycol) through printing on a hydrophobic layer that consists of fluoroalkylsilanes. Gold nanospheres of varying diameters selectively bind and assemble into nanostructures with reduced interparticle distances on the hydrophilic patterns of poly(ethylene glycol) surrounded with a hydrophobic background Read more
Published in Chemical Engineering Journal, 2020
Depending on the solvent and coating distance, spray-coating a dispersion composed of alkyl-silane functionalized nanoparticles and wax results in extremely water repellent surfaces with a water contact angle of 175° and a sliding angle of 3°. The formation of hierarchically structured surfaces upon evaporation of the solvent enables fabrication of fluorine-free, highly water repellent surfaces and provides high level of structural protection against mechanical abrasion. Read more
Published in Surface and Coating Technology, 2021
We present a universal solution to this challenge by benefiting from the unique micro-structure of paper. Our approach is based on transferring the structure of paper into a target material, to form a mechanical protection layer for nanomaterials that were deposited from solution-phase, i.e. spray-coating. We demonstrate this concept through the transfer of the structure of paper to a free-standing PDMS film using a simple molding process. Read more
Published in Progress in Organic Coatings, 2021
We report a robust water impact resistant all-organic superhydrophobic coating that is prepared from low-cost colloidal dispersion composed of carnauba wax and candle soot.The colloidal dispersion is stable and can be spray-coated onto virtually any surfaces. The coated surfaces exhibit superhydrophobicity with a water contact angle of 172° and sliding angle of 3°, and retain superhydrophobicity even after 400 cycles of continuous water spray with an impact pressure of 7.4 kPa. Read more
Published in Food Packaging and Shelf Life, 2021
Superhydrophobic coatings can prevent fouling and contamination of food packages. An additional capability is the minimization of food waste and improving consumer experience due to the easy sliding of food from the inner side of the package. In this article, we provide an overview of recent studies on the application of superhydrophobic coatings and surfaces for food packaging applications Read more
Published in Colloids and Surfaces B: Biointerfaces, 2021
We demonstrate the fabrication of mechanically durable superhydrophobic surfaces via an in-situ structuring strategy starting from natural carnauba wax and biocompatible polydimethylsiloxane (PDMS) materials. The hierarchically structured surface exhibits mechanical robustness as demonstrated with water impact and linear abrasion tests. We finally demonstrate repellence of the surfaces against a range of blood products including platelet suspension, erythrocyte suspension, fresh plasma, and whole blood. Read more
Published in Surface and Coatings Technology, 2021
This study reports a convenient and inexpensive approach to fabricate robust and fluorine‐free superhydrophobic fabrics based on the transfer of structured polymer films and hydrophobic nanoparticles. In this approach, polydimethylsiloxane (PDMS) is infused between sheets of fabric and paper, followed by curing and removal of the paper. Read more
Published in ACS Applied Nanomaterials, 2021
This study reports eco-friendly preparation of the surface-enhanced Raman scattering (SERS) substrate for machine learning-assisted detection of pesticides in water. The ML-mediated detection of harmful pesticides on a versatile, green, and inexpensive SERS platform appears to be promising for environmental applications. Read more
Published in Chemical Engineering Journal, 2022
We prepared a multifunctional superhydrophobic surface using eco-friendly materials: polydimethylsiloxane (PDMS) and carnauba wax. After deposition of a thin film of Ag, the surface gained surface-enhanced Raman scattering (SERS) activity and bactericidal property. Read more
Published in ACS Omega, 2022
CuO nanoparticles grown in situ on paper surface exhibit excellent antibacterial activity. Moreover, the fabricated surface shows excellent growth inhibition ability and bactericidal activity against both gram-negative and gram-positive bacteria, Escherichia coli and Staphylococcus aureus, as well as antifungal activity against Candida albicans, a common pathogenic fungus. Read more
Published in ACS Applied Materials & Interfaces, 2023
This study presents the formation of antimicrobial and plasmonic surfaces based on Ag–CuxO nanostructures using green synthesis methods and low-cost paper substrates. The fabricated nanostructured surfaces exhibit excellent bactericidal efficiency and high surface-enhanced Raman scattering (SERS) activity. Read more
Published in ACS Langmuir, 2023
This study report a fluorine-free and biocompatible superhydrophobic coating that can be thermally healed after abrasion. The coating is composed of silica nanoparticles and carnauba wax, and the self-healing is based on surface enrichment of wax in analogy to the wax secretion in plant leaves. The coating not only exhibits fast self-healing, just in 1 min under moderate heating, but also displays increased water repellency and thermal stability after healing. Read more
Published in Advanced Materials Interfaces, 2023
A mechanochemical approach for practical and solvent-free manufacturing of superhydrophobic surfaces is reported. This approach enables solvent-free and ultra-rapid preparation of superhydrophobic surfaces in a single-step without the need for any washing, separation, and drying steps. Read more
Published in Journal of Molecular Spectroscopy, 2023
Rotational transitions of propynal (HCCCHO) have been measured in the 150–900 GHz region by millimeter wave spectroscopy and in the far infrared region by high resolution FTIR spectroscopy using a synchrotron source. Read more
Published in ACS Applied Nano Materials, 2023
This study demonstrates a rapid and eco-friendly approach to preparing superhydrophobic surfaces by chemically grafting alkylsilane molecules onto silica nanoparticles using a mechanochemical process. Read more
Published in ACS Applied Materials & Interfaces, 2023
We present a mechanochemical activation strategy for solventless grafting of poly(dimethylsiloxane) (PDMS) onto glass, silicon wafers, and ceramics. Activation is achieved via ball milling PDMS without using any solvents or additives prior to application. Read more
Published in 67th International Symposium on Molecular Spectroscopy, 2012
It is believed that producing and trapping high concentrations of reactive species in solid molecular hydrogen will ultimately lead to the development of new high performance rocket fuels. We think the NH radical could be a viable candidate and try to produce it by photolyzing ammonia (NH3) at low temperature in solid parahydrogen. Upon 193.3 nm photolysis of NH3, we observe both NH2 and NH radical photoproducts. No significant changes in the NH radical concentration have been detected during a period of 3 hours at 1.8 K, even though the reaction NH + H2 rightarrow NH3 is highly exothermic and can occur by quantum mechanical tunneling even at these low temperatures. In contrast, the NH2 radical is only observed in FTIR scans recorded during photolysis and rapidly decays once the 193.3 nm laser is turned off. We will discuss the possible fates of NH2 and how conditions can be optimized to produce high concentrations of NH radicals.. Read more
Published in Australian Synchrotron User Meeting 2014, 2014
In this study, the spectrum of amorphous ice nanoparticles of submicron size in the 10 – 4000 cm-1 spectral range is investigated utilising the Infrared Spectrometer at the Australian Synchrotron. The optimum condition to generate amorphous ice nanoparticles will be presented followed by discussions of change of spectral features with respect to phase, size and temperature. Read more
Published in RACI PhysChem Student Conference, 2014
Published in RACI National Congress, 2014
Published in 11TH AUSTRALIAN CONFERENCE ON VIBRATIONAL SPECTROSCOPY & THE 5TH ASIAN SPECTROSCOPY CONFERENCE, 2015
we present various methods to retrieve the complex refractive indices of aerosols from FTIR spectra and discuss the ease of application and accuracy for each method. Small aerosols (<100 nm) attenuate the IR beam mainly by absorption which can be easily simulated by Rayleigh scattering, whereas scattering is dominant for larger particles (> a few micron) where more rigorous Mie scattering theory is needed. Read more
Published in RACI PhysChem Conference, 2016
Attended the RACI conference in the University of Canterbury, Christchurch, New Zealand. Read more
Published in Australian Synchrotron User Meeting 2016, 2016
we present mid-infrared (IR) spectra of formic acid aerosols recorded at atmospherically relevant temperatures of 80 – 210 K, and demonstrate an efficient method to extract refractive indices from measured spectra. The spectra indicate that the spectral bands below 1800 cm-1, especially around the C=O stretch region, show strong temperature dependence. Read more
Published in NanoTR-16, 2022
In this study, we explore two convenient approaches that can be used to fabricate plasmonic nanostructures, focusing on their applications in SEIRA. In the first approach, we employ electrohydrodynamic jet printing (e-Jet) to print arrays of narrow (~200 nm) polymer brushes that is a few μm long, followed by immobilizing commercial gold nanoparticles (NPs) or growing them in situ. Read more