Ion irradiation as a tool for modifying the surface and optical properties of plasma polymerised thin films
01 Jan 2015-
TL;DR: In this article, radio frequency (R.F.) glow discharge polyterpenol thin films were prepared on silicon wafers and irradiated with I10+ ions to fluences of 1 × 1010 and 1 ×1012 ions/cm2.
Abstract: Radio frequency (R.F.) glow discharge polyterpenol thin films were prepared on silicon wafers and irradiated with I10+ ions to fluences of 1 × 1010 and 1 × 1012 ions/cm2. Post-irradiation characterisation of these films indicated the development of well-defined nano-scale ion entry tracks, highlighting prospective applications for ion irradiated polyterpenol thin films in a variety of membrane and nanotube-fabrication functions. Optical characterisation showed the films to be optically transparent within the visible spectrum and revealed an ability to selectively control the thin film refractive index as a function of fluence. This indicates that ion irradiation processing may be employed to produce plasma-polymer waveguides to accommodate a variety of wavelengths. XRR probing of the substrate-thin film interface revealed interfacial roughness values comparable to those obtained for the uncoated substrate's surface (i.e., both on the order of 5 A), indicating minimal substrate etching during the plasma deposition process.
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TL;DR: In this article, a comparative study of 150 keV argon (Ar+) and oxygen (O+) ion implantation induced microstructural modifications in Bakelite Resistive Plate Chamber (RPC) detector material at different implantation fluences have been studied using Positron Annihilation Lifetime Spectroscopy (PALS).
8 citations
TL;DR: In this article, the effect of ion implantation on structural modification and electrical conductivity of Bakelite-resistive plate chamber (RPC) detector material used in high energy physics experiments was investigated.
Abstract: We have investigated the effect of ion implantation on structural modification and the electrical conductivity of Bakelite-resistive plate chamber (RPC) detector material used in high energy physics experiments. Samples of Bakelite polymer were exposed to 100 keV and 150 keV oxygen ions in the fluence of 1012 to 1015 ions cm−2. Ion implantation induced microstructural changes have been studied using positron annihilation lifetime spectroscopy, X-ray diffraction and Fourier transform infrared techniques. Positron lifetime parameters viz., o-Ps lifetime and its intensity showed formation of radicals, secondary ions due to the creation of interior tracks by high-energy ions followed by chain scission at lower fluence of 100 keV implantation. The decreased free volume size at 150 keV ion implantation is an indication of crosslinking and filling up of interior tracks by the implanted ions. Variation of ac conductivity with frequency obeys Jonscher power law at 100 keV and the conduction mechanism is explained by barrier hopping model.
7 citations
TL;DR: In this article, heavy ion irradiation of polyterpenol thin films synthesized from an environmentally sustainable precursor by radio-frequency plasma enhanced chemical vapor deposition was used to produce graphitic-polymer nanocomposite thin films.
Abstract: This study aimed to produce graphitic-polymer nanocomposite thin films via the swift heavy ion irradiation of polyterpenol thin films synthesized from an environmentally sustainable precursor by radio-frequency plasma enhanced chemical vapor deposition. Atomic force microscopy and scanning electron microscopy revealed fluence-dependent surface restructuring of the thin films leading to the formation of interconnected island structures, with no discernible delamination from the underlying aluminum substrate. Raman spectroscopy confirmed the development of D and G peaks associated with graphitic materials, whilst Fourier transform infrared spectroscopy indicated retention of the plasma polymer's chemical functionalities (including hydroxyl groups) within the material after irradiation. Graphitic-polymer nanocomposite films prepared by this dry and solvent-free process have numerous potential applications in biological assay, organic electronics, and membrane technology. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46498.
5 citations
23 May 2017
TL;DR: In this article, the effect of 80MeV 6+ Oxygen ion irradiation on the performance of DSSCs was reported and the effect was found to be due to the surface modification of the TiO2 coated films due to irradiation.
Abstract: The work reports the effect of 80MeV 6+ Oxygen ion irradiation on the performance of DSSCs TiO2 coated FTO were subjected to ion irradiation of fluences 1 × 1012 to 1 × 1014 ions/cm2 TiO2 coated FTOs were characterized with XRD for structural analysis and have shown anatase phase Irradiated films were used as electrodes for DSSCs We have observed that the irradiated light conversion efficiency of the cells was highest for fluence of 1 × 1013ions/cm2 and at the same fluence the cell parameters showed to be the best The reason may be due to the surface modification of the TiO2 coated films due to irradiation However lower fluences than 1 × 1013 ions/cm2 show less effect while higher fluence shown degrading effect on the cell performance which may be due to the worsening of contact between electrode and dyes
1 citations
References
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TL;DR: In this article, a new heuristic approach for minimizing possibly nonlinear and non-differentiable continuous space functions is presented, which requires few control variables, is robust, easy to use, and lends itself very well to parallel computation.
Abstract: A new heuristic approach for minimizing possibly nonlinear and non-differentiable continuous space functions is presented. By means of an extensive testbed it is demonstrated that the new method converges faster and with more certainty than many other acclaimed global optimization methods. The new method requires few control variables, is robust, easy to use, and lends itself very well to parallel computation.
24,053 citations
TL;DR: The solid-state nanopore proves to be a surprisingly versatile new single-molecule tool for biophysics and biotechnology.
Abstract: The passage of individual molecules through nanosized pores in membranes is central to many processes in biology. Previously, experiments have been restricted to naturally occurring nanopores, but advances in technology now allow artificial solid-state nanopores to be fabricated in insulating membranes. By monitoring ion currents and forces as molecules pass through a solid-state nanopore, it is possible to investigate a wide range of phenomena involving DNA, RNA and proteins. The solid-state nanopore proves to be a surprisingly versatile new single-molecule tool for biophysics and biotechnology.
1,861 citations
TL;DR: A comprehensive overview on the development of polymeric membranes having advanced or novel functions in the various membrane sepn processes for liq. and gaseous mixts can be found in this paper.
1,841 citations
TL;DR: MOTOFIT as mentioned in this paper uses a slab-model approach with the Abeles matrix method, and extensions for surface roughness to perform nonlinear least-squares regression on the experimental reflectivity curves.
Abstract: The contrast-variation technique is employed in multiple-contrast neutron/X-ray reflectometry experiments to highlight scattering from different structural components that are present at a surface or interface. The advantage of this technique is that the structural model used to describe the interfacial scattering length density profile must apply to all the contrasts measured. A new reflectivity analysis package, MOTOFIT, which runs in the IGOR Pro environment (http://www.wavemetrics.com), has been created to aid the simultaneous fitting (with the same structural model) of these multiple-contrast data, using an intuitive graphical user interface, which most co-refinement packages do not possess. MOTOFIT uses a slab-model approach with the Abeles matrix method, and extensions for surface roughness to perform non-linear least-squares regression on the experimental reflectivity curves. Other features, such as the ability to create complicated interparameter constraints or analyse reflectivity from multilayers, simulated annealing, etc., make MOTOFIT a powerful reflectometry analysis package
959 citations
01 Dec 2001-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: A survey of radiation-processing methods of industrial interest, ranging from technologies already commercially well established, through innovations in the active R&D stage which show exceptional promise for future commercial use can be found in this article.
Abstract: Ionizing radiation has been found to be widely applicable in modifying the structure and properties of polymers, and can be used to tailor the performance of either bulk materials or surfaces. Fifty years of research in polymer radiation chemistry has led to numerous applications of commercial and economic importance, and work remains active in the application of radiation to practical uses involving polymeric materials. This paper provides a survey of radiation-processing methods of industrial interest, ranging from technologies already commercially well established, through innovations in the active R&D stage which show exceptional promise for future commercial use. Radiation-processing technologies are discussed under the following categories: cross-linking of plastics and rubbers, curing of coatings and inks, heat-shrink products, fiber–matrix composites, chain-scission for processing control, surface modification, grafting, hydrogels, sterilization, natural product enhancement, plastics recycling, ceramic precursors, electronic property materials, ion-track membranes and lithography for microdevice production. In addition to new technological innovations utilizing conventional gamma and e-beam sources, a number of promising new applications make use of novel radiation types which include ion beams (heavy ions, light ions, highly focused microscopic beams and high-intensity pulses), soft X-rays which are focused, coherent X-rays (from a synchrotron) and e-beams which undergo scattering to generate patterns.
530 citations