Diffusivity of adatoms on plasma-exposed surfaces determined from the ionization energy approximation and ionic polarizability

Microscopic surface diffusivity theory based on atomic ionization energy concept is developed to explain the variations of the atomic and displacement polarizations with respect to the surface diffusion activation energy of adatoms in the process of self-assembly of quantum dots on plasma-exposed surfaces. These polarizations are derived classically, while the atomic polarization is quantized to obtain the microscopic atomic polarizability. The surface diffusivity equation is derived as a function of the ionization energy. The results of this work can be used to fine-tune the delivery rates of different adatoms onto nanostructure growth surfaces and optimize the low-temperature plasma based nanoscale synthesis processes.Comment: Published versio

Electron-conduction mechanism and specific heat above transition temperature in LaFeAsO and BaFe(2)As(2) superconductors

The ionization energy theory is used to calculate the evolution of the resistivity and specific heat curves with respect to different doping elements in the recently discovered superconducting Pnictide materials. Subsequently, the electron-conduction mechanism in the Pnictides above the structural transition temperature is explained unambiguously, which is also consistent with other strongly correlated matter, such as cuprates, manganites, titanates and magnetic semiconductors. Therefore, the superconductivity is not uniquely corresponds to the electronic properties above the structural transition temperature. Detailed prediction are given on these compounds for various doping elements, namely, La(Sm,Ce,Ba,Sr,Ca)FeAsO(F,Cl,Br) and Ba(Sr,Ca,K,Rb,Cs)Fe(2)As(2).Comment: Published online: J. Supercond. Nov. Magn. (2009

Nano Technology and Gas Plasma as Novel Therapeutic Strategies for Ovarian Cancer Oncotherapy

Ovarian cancer (OC) is associated with a high rate of resistance to most chemotherapy drugs and thus novel therapies are crucial to overcoming these obstacles. The technological advances in nanotechnology make it possible to adapt these approaches for the treatment of chemo-resistant OC. In parallel, it is also evident that this emerging technology plays crucial roles in other medical areas including wound healing, treatment of viral infection and applications in dentistry. With the advancement of nanotechnology, nano dependent therapies are attractive viable alternatives to conventional therapies for various diseases, especially cancers. Nanoparticles (NPs) are a suitable platform for cytotoxic agent delivery and aiding early diagnosis of disease, which can lead to improving outcomes for these patients. Gas plasma oncotherapy is an innovative modality and shows huge potentials in cancer treatment and may emerge as the fifth cancer treatment modality together with surgery, radiotherapy, chemotherapy, targeted therapy and immunotherapy. The combination of nanoparticle and gas plasma therapy could lead to the discovery of an alternative effective treatment approach in these resistant tumors leading to improvement of OC prognosis. Here, we highlighted the two novel modalities with known multiple biological targets and underlying mechanisms appropriate for their application in OC treatment. This chapter explores the utility of combination or multimodal of novel nanotherapeutic agents in the treatment of OC

Lung Cancer Oncotherapy through Novel Modalities: Gas Plasma and Nanoparticle Technologies

Cold atmospheric pressure plasma (CAP) is emerging as new healthcare technology and it has a high potential through physical and chemical effects for cancer treatment. Recently, CAP, plasma activated liquid (PAL), and nanomaterial have been significant advances in oncotherapy. Reactive oxygen-nitrogen species (RONS), electrical field, and other agents generated by CAP interact with cells and induce selective responses between the malignant and normal cells. Nanomedicine enhances therapeutic effectiveness and decreases the side effects of traditional treatments due to their target delivery and dispersion in tumor tissue. There are various nanocarriers (NCs) which based on their properties can be used for the delivery of different agents. The combination of gas plasma and nanomaterials technologies is a new multimodal treatment in cancer treatment, therefore, is expected that the conjunction of these technologies addresses many of the oncology challenges. This chapter provides a framework for current research of NC and gas plasma therapies for lung cancer. Herein, we focus on the application of gas plasmas and nanotechnology to drug and gene delivery and highlight several outcomes of its. The types and features of the mentioned therapeutics strategy as novel classes for treating lung cancer individually and synergistic were examined

Microplasmas for Advanced Materials and Devices

Microplasmas are low-temperature plasmas that feature microscale dimensions and a unique high-energy-density and a nonequilibrium reactive environment, which makes them promising for the fabrication of advanced nanomaterials and devices for diverse applications. Here, recent microplasma applications are examined, spanning from high-throughput, printing-technology-compatible synthesis of nanocrystalline particles of common materials types, to water purification and optoelectronic devices. Microplasmas combined with gaseous and/or liquid media at low temperatures and atmospheric pressure open new ways to form advanced functional materials and devices. Specific examples include gas-phase, substrate-free, plasma-liquid, and surface-supported synthesis of metallic, semiconducting, metal oxide, and carbon-based nanomaterials. Representative applications of microplasmas of particular importance to materials science and technology include light sources for multipurpose, efficient VUV/UV light sources for photochemical materials processing and spectroscopic materials analysis, surface disinfection, water purification, active electromagnetic devices based on artificial microplasma optical materials, and other devices and systems including the plasma transistor. The current limitations and future opportunities for microplasma applications in materials related fields are highlighted.</p

Future antiviral polymers by plasma processing

Coronavirus disease 2019 (COVID-19) is largely threatening global public health, social stability, and economy. Efforts of the scientific community are turning to this global crisis and should present future preventative measures. With recent trends in polymer science that use plasma to activate and enhance the functionalities of polymer surfaces by surface etching, surface grafting, coating and activation combined with recent advances in understanding polymer-virus interactions at the nanoscale, it is promising to employ advanced plasma processing for smart antiviral applications. This trend article highlights the innovative and emerging directions and approaches in plasma-based surface engineering to create antiviral polymers. After introducing the unique features of plasma processing of polymers, novel plasma strategies that can be applied to engineer polymers with antiviral properties are presented and critically evaluated. The challenges and future perspectives of exploiting the unique plasma-specific effects to engineer smart polymers with virus-capture, virus-detection, virus-repelling, and/or virus-inactivation functionalities for biomedical applications are analysed and discussed

Plasma-catalytic CO2 hydrogenation to ethane in a dielectric barrier discharge reactor

Anthropogenic greenhouse gas emissions have caused changes to the Earth's climate, resulting in catastrophic weather events that are becoming more frequent and intense. Developing carbon-neutral processes for CO2 conversion powered by renewable energy is one way of attaining a circular economy, as waste CO2 is converted to a new carbon-containing product, without also being created as a by-product during the process. Plasma-catalysis is gaining increasing interest for CO2 conversion and utilisation under mild conditions, particularly CO2 conversion to green chemicals and fuels using renewable hydrogen, as this electrified process can easily be combined with clean and renewable energy to ensure a carbon-neutral process. Previous studies have mainly focussed on the production of methane from CO2 and H2; however, ethane (C2H6) is a much more valuable product. In this work, we report a non-thermal plasma-catalytic process for the conversion of CO2 into C2H6 in a dielectric barrier discharge (DBD) reactor. The influence of a variety of alumina-supported metal catalysts (Ru, Cu, Ni and Fe) on the plasma-catalytic CO2 hydrogenation to C2H6 was evaluated. The Ru catalyst attained the highest selectivity towards C2H6, at almost 40%. The Ru catalyst also increased the energy efficiency of the process to around 18%, in comparison to the plasma reaction using pure alumina (12%). The Ru catalyst also achieved the highest H2 conversion at 29%. Plasma-assisted production of C2H6 is a new promising process for the utilisation of CO2 via carbon-neutral electrified gas conversion.</p

Antimicrobial adhesive films by plasma-enabled polymerisation of m-cresol

This work reveals a versatile new method to produce films with antimicrobial properties that can also bond materials together with robust tensile adhesive strength. Specifically, we demonstrate the formation of coatings by using a dielectric barrier discharge (DBD) plasma to convert a liquid small-molecule precursor, m-cresol, to a solid film via plasma-assisted on-surface polymerisation. The films are quite appealing from a sustainability perspective: they are produced using a low-energy process and from a molecule produced in abundance as a by-product of coal tar processing. This process consumes only 1.5 Wh of electricity to create a 1 cm2 film, which is much lower than other methods commonly used for film deposition, such as chemical vapour deposition (CVD). Plasma treatments were performed in plain air without the need for any carrier or precursor gas, with a variety of exposure durations. By varying the plasma parameters, it is possible to modify both the adhesive property of the film, which is at a maximum at a 1 min plasma exposure, and the antimicrobial property of the film against Escherichia coli, which is at a maximum at a 30 s exposure

Enhancing plasma-catalytic toluene oxidation: Unraveling the role of Lewis-acid sites on δ-MnO2

The emission of volatile organic compounds (VOCs) into the air, primarily due to human activities, has caused significant environmental pollution and health concerns. In response, the development of advanced environmental catalysts is crucial, and δ-MnO2 has emerged as a promising material for efficient VOC oxidation. However, the identification of the specific active sites and the underlying oxidation mechanisms of this material remain unclear, hindering the development and optimization of high-activity catalysts. Herein, we present a strategy to remove the internal water and hydrated cations from δ-MnO2, thereby unblocking the inter-lamellar gaps and exposing the internal Lewis-acid sites, while maintaining other physical and chemical characteristics of the sample unchanged. Notably, the well-defined δ-MnO2 catalysts with more accessible interlayer Lewis-acid sites exhibited significantly enhanced catalytic activity in toluene oxidation, demonstrated in both two-stage plasma catalysis and single-stage ozonation processes. A quantitative analysis of Lewis-acid sites and initial toluene reaction rates revealed that these Lewis-acid sites serve as the active centers for toluene adsorption and activation, and the heterogeneous reaction between toluene and ozone follows the Langmuir-Hinshelwood mechanism. Moreover, in-depth analysis of byproducts showed that δ-MnO2 rich in Lewis-acid sites promoted the oxidation of intermediates, such as esters, hydrazides, and ketones, leading to a more complete toluene oxidation. This work not only fully explores the potential of δ-MnO2 as a catalyst, but also provides valuable insights into the elucidation of unknown catalytic active sites, potentially paving the way for the rational design of more efficient catalysts for VOC oxidation