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Robert D Short - One of the best experts on this subject based on the ideXlab platform.

  • Chemical and thermo‐responsive characterisation of surfaces formed by Plasma Polymerisation of N‐isopropyl acrylamide
    Surface and Interface Analysis, 2020
    Co-Authors: Nial A Bullett, Robert D Short, Rosnita A Talib, Sally L Mcarthur, A G Shard
    Abstract:

    Plasma Polymerisation of N -isopropyl acrylamide (NIPAAm) presents an exciting route for the production of thermally responsive coatings on a wide variety of substrates for applications in tissue culture and microfluidics. One issue associated with the Polymerisation of NIPAAm via Plasma Polymerisation is the limited volatility of the monomer and the subsequent requirement for monomer and reactor heating to create and maintain the vapour. It is already well established that power is critical in the balance between polymer functionality and coating stability in Plasma polymers. However, little is known of how reactor and substrate temperatures may be used to influence the physico-chemical characteristics of polymers produced from such low-volatility monomers. In this paper, we examine the effects of a range of Plasma deposition parameters on the functionality and stability of Plasma-polymerised NIPAAm surfaces. X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure spectroscopy (NEXAFS), ellipsometry and contact angle goniometry have been used to examine coating chemistry, stability in aqueous environments, deposition rates and thermo-responsive behaviour. Our results indicate that Plasma Polymerisation at low powers and low temperatures enhances the ability of Plasma-polymerised NIPAAm to display a wettability phase transition, but also contributes to instability of the coating to dissolution or delamination in water. Our spectroscopic measurements confirm that retention of the monomer structure is facilitated by low power and temperature deposition and reveal that conversion of the amide groups to amine and nitrile groups occurs during the Polymerisation process, particularly at high discharge powers.

  • Surfaces to enhance matrix deposition for wound healing
    Wound Practice & Research: Journal of the Australian Wound Management Association, 2018
    Co-Authors: T Fernandez, Robert D Short, Xanthe L. Strudwick, Sameer A. Al-bataineh, Allison J. Cowin
    Abstract:

    Introduction: The next generation of wound dressings will actively participate in the wound healing process, helping the body to heal itself. For deep and/or chronic wounds a dermal scaffold is often required prior to the application of a skin graft or other therapy that encourages re-epithelialisation and the restoration of the barrier function. The aim of this study was to determine if electrospinning and Plasma Polymerisation could be used to generate a scaffold that would support fibroblast growth and extracellular deposition. Methods: A totally synthetic electrospun dermal replacement was produced coated with an allylamine Plasma polymer and its impact upon cellular processes assessed 'in vitro'. Results: The scaffold encouraged increased adhesion and rapid migration of human dermal fibroblasts into the scaffold. Fibroblasts rapidly proliferated to populate the scaffold and deposited significantly more collagen I on scaffolds coated with the allylamine Plasma polymer than the uncoated poly(lactic acid) scaffold or scaffolds coated with other Plasma polymers (acrylic acid or 1,7' octadiene). Conclusions: Electrospinning and Plasma Polymerisation are both versatile and widely used techniques that are also suitable for large-scale manufacture of scaffolds. These properties increase the potential of the scaffold to include its use as a cell delivery device for the delivery of fibroblasts, including their associated extracellular matrix and mitogens to chronic wounds.

  • nanoscale deposition of chemically functionalised films via Plasma Polymerisation
    RSC Advances, 2013
    Co-Authors: Andrew Michelmore, J W Bradley, David A Steele, Jason D Whittle, Robert D Short
    Abstract:

    Plasma Polymerisation is a technologically important surface engineering process capable of depositing ultra-thin functionalised films for a variety of purposes. It has many advantages over other surface engineering processes, including that it is completely dry, can be used for complex geometries, and the physico-chemical properties of the film can be tailored through judicious choice of processing conditions. Despite this, the mechanisms of film growth are largely unknown, and current models are based on purely chemical arguments. Consideration of some basic Plasma physics shows that some species can arrive at surfaces with energies greater than 1000 kJ mol−1 (>10 eV), and thus open a range of surface reactions that have not been considered previously. This review aims to close the gap between the physics and chemistry of reactive Plasma systems.

  • design of a microPlasma device for spatially localised Plasma Polymerisation
    Plasma Processes and Polymers, 2011
    Co-Authors: Sameer A Albataineh, Endre J Szili, Apurva Mishra, Sungjin Park, Gary J Eden, Hans J Griesser, Nicolas H Voelcker, Robert D Short, David A Steele
    Abstract:

    There is considerable interest in the spatial control of Plasma Polymerisation such as to produce sub-millimetre features with high fidelity, versatility and reproducibility, for example, for arrays or writable specific patterns. This study reports the design of a microcavity Plasma device and a method for its fabrication, with the device comprising a single cavity of � 400 mm diameter. The device can be fabricated within a short time and at low cost in a standard laboratory, with no need for a clean room facility. The device is capable of multiple operations in Plasma Polymerisation mode. XPS imaging combined with small-spot ROI analysis showed localised thin film deposition of an acrylic acid Plasma polymer with good retention of carboxylate groups from the monomer. The device can be configured with flexibility and addressedforPlasma polymer writing of complex patterns.

  • testing the hypothesis comments on Plasma Polymerisation of acrylic acid revisited
    Plasma Processes and Polymers, 2010
    Co-Authors: Robert D Short, David A Steele
    Abstract:

    Using perhaps the most comprehensive data set for the Plasma Polymerisation of acrylic acid (AA) currently available, the hypothesis that different Plasma regimes for AA may be revealed by plotting the deposition rate normalised by flow rate (Rm/F) against the composite parameter of (W/F)−1, where W is the Plasma power, is explored. The analyses possibly support the view that an apparent activation energy Ea can be obtained from the plot at low W, but based on other data (notably, mass spectrometry and ion flux) the processes that are on-going in this regime are interpreted differently.

Mohan V Jacob - One of the best experts on this subject based on the ideXlab platform.

  • Fabrication and Characterization of RF Plasma Polymerized Thin Films from 3,7-Dimethyl-1,6-octadien-3-ol for Electronic and Biomaterial Applications
    Advanced Materials Research, 2020
    Co-Authors: Kateryna Bazaka, Mohan V Jacob, Robert A Shanks
    Abstract:

    Poly(linalool) thin films were fabricated using RF Plasma Polymerisation. All films were found to be smooth, defect-free surfaces with average roughness of 0.44 nm. The FTIR analysis of the polymer showed a notable reduction in –OH moiety and complete dissociation of C=C unsaturation compared to the monomer, and presence of a ketone band absent from the spectrum of the monomer. Poly(linalool) were characterised by chain branching and a large quantity of short polymer chains. Films were optically transparent, with refractive index and extinction coefficient of 1.55 and 0.001 (at 500 nm) respectively, indicating a potential application as an encapsulating (protective) coating for circuit boards. The optical band gap was calculated to be 2.82 eV, which is in the semiconducting energy gap region.

  • New encapsulating materials for implantable devices
    2013
    Co-Authors: Kateryna Bazaka, Elena P Ivanova, Wojciech Chrzanowski, Natkunam Ketheesan, Mohan V Jacob
    Abstract:

    Synthetic, natural, or composite, biomaterials occupy a key position in the management of disease and support continuous advancement of health care. Clinical utility of many permanent and biodegradable implants can be significantly improved via surface modification. Here, we discuss a novel polymer material developed from essential oil-based monoterpene alcohol using Plasma Polymerisation. The developed coatings are cytocompatible and limit adhesion and proliferation of a variety of pathogens. The coating can also be used to control degradation behaviour of resorbable materials, such as magnesium.

  • Plasma Polymerisation and retention of antibacterial properties of terpinen 4 ol
    Science and technology against microbial pathogens: research development and evaluation: International Conference on Antimicrobial Research (ICAR2010), 2011
    Co-Authors: Kateryna Bazaka, Mohan V Jacob, Russell J Crawford, Elena P Ivanova
    Abstract:

    Plasma Polymerisation was used to deposit thin oligomeric films of terpinen-4-ol on a range of substrates. The coatings were examined in terms of their chemical properties and surface architecture to ascertain the changes in chemical composition as a result of exposure to the Plasma field. The antifouling and antimicrobial activity of oligomeric terpinen-4-ol coatings were then examined against such human pathogens as Staphylococcus aureus, Pseudomonas aeruginosa and Staphylococcus epidermis. The bacterial adhesion patterns were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal scanning laser microscopy (CSLM).

  • A study of a retention of antimicrobial activity by Plasma polymerized terpinen-4-ol thin films
    Materials Science Forum, 2010
    Co-Authors: Kateryna Bazaka, Mohan V Jacob, Elena P Ivanova
    Abstract:

    Terpinen-4-ol is the main constituent of Melaleuca alternifolia essential oil known for its biocidal and anti-inflammatory properties. The possibility of fabricating polymer thin films from terpinen-4-ol using radio frequency (RF) Plasma Polymerisation for the prevention of the growth of Pseudomonas aeruginosa was investigated, and the properties of the resultant films compared against their biologically active precursor. Films fabricated at 10 W prevented bacterial attachment and EPS secretion, whilst polyterpenol films deposited at 25 W demonstrated no biocidal activity against the pathogen.

  • Effect of Iodine Doping on Surface and Optical Properties of Polyterpenol Thin Films
    Materials Science Forum, 2010
    Co-Authors: Kateryna Bazaka, Mohan V Jacob
    Abstract:

    This study presents the effect of iodine doping on optical and surface properties of polyterpenol thin films deposited from non-synthetic precursor by means of Plasma Polymerisation. Spectroscopic ellipsometry studies showed iodine doping reduced the optical band gap from 2.82 eV to 1.50 eV for pristine and doped samples respectively. Higher levels of doping notably reduced the transparency of films, an issue if material is considered for applications that require high transparency. Contact angle studies demonstrated higher hydrophilicity for films deposited at increased doping levels, results confirmed by XPS Spectroscopy and FTIR. Doping had no significant effect on the surface profile or roughness of the film.

Kateryna Bazaka - One of the best experts on this subject based on the ideXlab platform.

  • Fabrication and Characterization of RF Plasma Polymerized Thin Films from 3,7-Dimethyl-1,6-octadien-3-ol for Electronic and Biomaterial Applications
    Advanced Materials Research, 2020
    Co-Authors: Kateryna Bazaka, Mohan V Jacob, Robert A Shanks
    Abstract:

    Poly(linalool) thin films were fabricated using RF Plasma Polymerisation. All films were found to be smooth, defect-free surfaces with average roughness of 0.44 nm. The FTIR analysis of the polymer showed a notable reduction in –OH moiety and complete dissociation of C=C unsaturation compared to the monomer, and presence of a ketone band absent from the spectrum of the monomer. Poly(linalool) were characterised by chain branching and a large quantity of short polymer chains. Films were optically transparent, with refractive index and extinction coefficient of 1.55 and 0.001 (at 500 nm) respectively, indicating a potential application as an encapsulating (protective) coating for circuit boards. The optical band gap was calculated to be 2.82 eV, which is in the semiconducting energy gap region.

  • New encapsulating materials for implantable devices
    2013
    Co-Authors: Kateryna Bazaka, Elena P Ivanova, Wojciech Chrzanowski, Natkunam Ketheesan, Mohan V Jacob
    Abstract:

    Synthetic, natural, or composite, biomaterials occupy a key position in the management of disease and support continuous advancement of health care. Clinical utility of many permanent and biodegradable implants can be significantly improved via surface modification. Here, we discuss a novel polymer material developed from essential oil-based monoterpene alcohol using Plasma Polymerisation. The developed coatings are cytocompatible and limit adhesion and proliferation of a variety of pathogens. The coating can also be used to control degradation behaviour of resorbable materials, such as magnesium.

  • Plasma Polymerisation and retention of antibacterial properties of terpinen 4 ol
    Science and technology against microbial pathogens: research development and evaluation: International Conference on Antimicrobial Research (ICAR2010), 2011
    Co-Authors: Kateryna Bazaka, Mohan V Jacob, Russell J Crawford, Elena P Ivanova
    Abstract:

    Plasma Polymerisation was used to deposit thin oligomeric films of terpinen-4-ol on a range of substrates. The coatings were examined in terms of their chemical properties and surface architecture to ascertain the changes in chemical composition as a result of exposure to the Plasma field. The antifouling and antimicrobial activity of oligomeric terpinen-4-ol coatings were then examined against such human pathogens as Staphylococcus aureus, Pseudomonas aeruginosa and Staphylococcus epidermis. The bacterial adhesion patterns were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal scanning laser microscopy (CSLM).

  • A study of a retention of antimicrobial activity by Plasma polymerized terpinen-4-ol thin films
    Materials Science Forum, 2010
    Co-Authors: Kateryna Bazaka, Mohan V Jacob, Elena P Ivanova
    Abstract:

    Terpinen-4-ol is the main constituent of Melaleuca alternifolia essential oil known for its biocidal and anti-inflammatory properties. The possibility of fabricating polymer thin films from terpinen-4-ol using radio frequency (RF) Plasma Polymerisation for the prevention of the growth of Pseudomonas aeruginosa was investigated, and the properties of the resultant films compared against their biologically active precursor. Films fabricated at 10 W prevented bacterial attachment and EPS secretion, whilst polyterpenol films deposited at 25 W demonstrated no biocidal activity against the pathogen.

  • Effect of Iodine Doping on Surface and Optical Properties of Polyterpenol Thin Films
    Materials Science Forum, 2010
    Co-Authors: Kateryna Bazaka, Mohan V Jacob
    Abstract:

    This study presents the effect of iodine doping on optical and surface properties of polyterpenol thin films deposited from non-synthetic precursor by means of Plasma Polymerisation. Spectroscopic ellipsometry studies showed iodine doping reduced the optical band gap from 2.82 eV to 1.50 eV for pristine and doped samples respectively. Higher levels of doping notably reduced the transparency of films, an issue if material is considered for applications that require high transparency. Contact angle studies demonstrated higher hydrophilicity for films deposited at increased doping levels, results confirmed by XPS Spectroscopy and FTIR. Doping had no significant effect on the surface profile or roughness of the film.

Elena P Ivanova - One of the best experts on this subject based on the ideXlab platform.

  • New encapsulating materials for implantable devices
    2013
    Co-Authors: Kateryna Bazaka, Elena P Ivanova, Wojciech Chrzanowski, Natkunam Ketheesan, Mohan V Jacob
    Abstract:

    Synthetic, natural, or composite, biomaterials occupy a key position in the management of disease and support continuous advancement of health care. Clinical utility of many permanent and biodegradable implants can be significantly improved via surface modification. Here, we discuss a novel polymer material developed from essential oil-based monoterpene alcohol using Plasma Polymerisation. The developed coatings are cytocompatible and limit adhesion and proliferation of a variety of pathogens. The coating can also be used to control degradation behaviour of resorbable materials, such as magnesium.

  • Plasma Polymerisation and retention of antibacterial properties of terpinen 4 ol
    Science and technology against microbial pathogens: research development and evaluation: International Conference on Antimicrobial Research (ICAR2010), 2011
    Co-Authors: Kateryna Bazaka, Mohan V Jacob, Russell J Crawford, Elena P Ivanova
    Abstract:

    Plasma Polymerisation was used to deposit thin oligomeric films of terpinen-4-ol on a range of substrates. The coatings were examined in terms of their chemical properties and surface architecture to ascertain the changes in chemical composition as a result of exposure to the Plasma field. The antifouling and antimicrobial activity of oligomeric terpinen-4-ol coatings were then examined against such human pathogens as Staphylococcus aureus, Pseudomonas aeruginosa and Staphylococcus epidermis. The bacterial adhesion patterns were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal scanning laser microscopy (CSLM).

  • A study of a retention of antimicrobial activity by Plasma polymerized terpinen-4-ol thin films
    Materials Science Forum, 2010
    Co-Authors: Kateryna Bazaka, Mohan V Jacob, Elena P Ivanova
    Abstract:

    Terpinen-4-ol is the main constituent of Melaleuca alternifolia essential oil known for its biocidal and anti-inflammatory properties. The possibility of fabricating polymer thin films from terpinen-4-ol using radio frequency (RF) Plasma Polymerisation for the prevention of the growth of Pseudomonas aeruginosa was investigated, and the properties of the resultant films compared against their biologically active precursor. Films fabricated at 10 W prevented bacterial attachment and EPS secretion, whilst polyterpenol films deposited at 25 W demonstrated no biocidal activity against the pathogen.

Farzaneh Arefikhonsari - One of the best experts on this subject based on the ideXlab platform.

  • design of calcium phosphate scaffolds with controlled simvastatin release by Plasma Polymerisation
    Polymer, 2016
    Co-Authors: Cristina Canal, Sudhir Bhatt, Jerome Pulpytel, Farzaneh Arefikhonsari, Kanupriya Khurana, Sara Gallinetti, M P Ginebra
    Abstract:

    Calcium Phosphates (CaPs) have excellent bone regeneration capacity, and their combination with specific drugs is of interest because it allows adding new functionalities. In CaPs, drug release is mainly driven by diffusion, which is strongly affected by the porosity of the matrix and the drug-material interaction. Therefore, it is very difficult to tune their drug release properties beyond their intrinsic properties. Furthermore, when the CaPs are designed as scaffolds, the increased complexity of the macrostructure further complicates the issue.; This work investigates for the first time the use of biocompatible Plasma-polymers to provide a tool to control drug release from drug-loaded CaP scaffolds with complex surfaces and intricate 3D structure. Two different CaPs were selected displaying great differences in microstructure: low-temperature CaPs (Calcium-deficient hydroxyapatite cements, CDHA) and sintered CaP ceramics (beta-Tricalcium Phosphate, beta-TCP). The deposition of PCL-co-PEG (1: 4) copolymers on CaPs was achieved by a low pressure Plasma process, which allowed coating the inner regions of the scaffolds up to a certain depth. The coating covered the micro and nanopores of the CaPs surface and produced complex geometries presenting a nano and micro rough morphology which lead to low wettability despite the hydrophilicity of the copolymer. Plasma coating with PCL-co-PEG on scaffolds loaded with Simvastatin acid (potentially osteogenic and angiogenic) allowed delaying and modulating the drug release from the bone scaffolds depending on the thickness of the layer deposited, which, in turn depends on the initial specific surface area of the CaP. (C) 2016 Elsevier Ltd. All rights reserved.

  • low and atmospheric Plasma Polymerisation of nanocoatings for bio applications
    Surface Innovations, 2015
    Co-Authors: Sudhir Bhatt, Jerome Pulpytel, Farzaneh Arefikhonsari
    Abstract:

    There exists an abundant literature on polymers used for biomedical applications. However, the research described in this article deals with the Plasma (co)Polymerisation of different organic precursors for surface modifications of a variety of substrates in order to tailor the physico-chemical properties of the substrates for tuneable biomolecule–surface interactions. The major part of the work presented focuses on the low-pressure inductively excited Plasma-enhanced chemical vapour deposition of organic precursors for the functionalisations of material. In the second part of the article, an open-air custom-made atmospheric-pressure dielectric barrier discharge (DBD) Plasma jet is discussed for the anti-fouling applications. This special focus aims to elaborate the state of the art of different low and atmospheric pressure Plasma-deposited polymers for anti-fouling applications, cell–surface interactions and tissue engineering applications.

  • amphiphilic copolymer coatings via Plasma Polymerisation process switching and anti biofouling characteristics
    Plasma Processes and Polymers, 2011
    Co-Authors: Jerome Pulpytel, Virendra Kumar, Guido Giudetti, H Rauscher, Francois Rossi, Farzaneh Arefikhonsari
    Abstract:

    Environmentally benign-solvent free Plasma process is employed to produce nanostructured PFDA-co-DEGDME amphiphilic coatings via Plasma co-Polymerisation of 1H,1H,2H,2H-perfluorodecyl acrylate (PFDA) and diethyleneglycol dimethyl ether (DEGDME) precursors in a low pressure-RF-inductively excited tubular Plasma reactor using argon as a carrier gas. The Plasma-polymerised coatings are characterised by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and contact angle measurements. PFDA-co-DEGDME coatings with varying chemical environments and morphologies are achieved by varying the Plasma parameters such as, continuous wave (CW) and pulse modulated (PM) Plasma mode, and Plasma deposition time. Plasma polymerised PFDA-co-DEGDME coatings are found to exhibit a switching property in terms of wettability, i.e., from hydrophobic to hydrophilic and vice versa, in response to the contacting environment. Quartz crystal microbalance (QCM) is used to study the adhesion of two model proteins, namely, human serum albumin (HSA) and fibrinogen (FGN) in continuous flow conditions, which reveals the protein repellent, i.e., anti-biofouling characteristics of the PFDA-co-DEGDME amphiphilic coatings.