Electron irradiation is a process which involves using electrons, usually of high energy, to treat an object for a variety of purposes. Irradiation is the process by which an item is exposed to Radiation. This may take place under elevated temperatures and nitrogen atmosphere. Possible uses for electron irradiation include Sterilization (microbiology) and to cross-link polymers. Sterilization (or sterilisation, see spelling differences) refers to any process that effectively kills or eliminates transmissible agents (such as Fungi Cross-links are bonds that link one Polymer chain to another They can be Covalent bonds or Ionic bonds "Polymer chains" can refer
Electron energies typically varies from the keV to MeV range, depending on the depth of penetration required. The irradiation dose is usually measured in Gray (unit) but also in Mrads. The gray (symbol Gy is the SI unit of absorbed radiation dose. The rad is a largely obsolete unit of absorbed Radiation dose with symbol rad. Where 1Gy is equivalent to 100rad.
In polymers, an electron beam may be used on the material to induce effects such as chain scission (which makes the polymer chain shorter) and cross linking. Cathode rays (also called an electron beam or e-beam) are streams of Electrons observed in Vacuum tubes i Cross-links are bonds that link one Polymer chain to another They can be Covalent bonds or Ionic bonds "Polymer chains" can refer The result is a change in the properties of the polymer which is intended to extend the range of applications for the material. The effects of irradiation may also include changes in crystallinity as well as microstructure. Crystallinity refers to the degree of structural order in a Solid. Microstructure refers to the microscopic description of the individual constituents of a Material. Usually, the irradiation process degrades the polymer. Polymer degradation is a change in the properties - Tensile strength, Colour, shape etc - of a Polymer or polymer based product under the influence of The irradiated polymers may sometimes be characterized using DSC, XRD, FTIR, or SEM. Differential scanning calorimetry or DSC is a thermoanalytical technique in which the difference in the amount of Heat required to increase the Temperature X-ray crystallography is a method of determining the arrangement of Atoms within a Crystal, in which a beam of X-rays strikes a crystal and scatters Fourier transform spectroscopy is a measurement technique whereby spectra are collected based on measurements of the temporal coherence of a radiative source The scanning electron microscope ( SEM) is a type of Electron microscope that images the sample surface by scanning it with a high-energy beam of Electrons
In poly(vinylidene fluoride-trifluoroethylene) copolymers, high-energy electron irradiation lowers the energy barrier for the ferroelectric-paraelectric phase transition and reduces polarization hysteresis losses in the material [1].
See also
Examples of Irradiation
- Z. Electron beam lithography (often abbreviated as e-beam lithography) is the practice of scanning a beam of Electrons in a patterned fashion across a surface covered Beta particles are high-energy high-speed Electrons or Positrons emitted by certain types of Radioactive nuclei such as Potassium -40 In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted Sterilization (or sterilisation, see spelling differences) refers to any process that effectively kills or eliminates transmissible agents (such as Fungi Y. Cheng, V. Bharti, T. Mai, T. -B. Xu, Q. M. Zhang, T. Ramotowski, K. A. Wright, R. Ting, "Effect of High Energy Electron Irradiation on the Electromechanical Properties of Poly(vinylidene Fluoride-Trifluoroethylene) 50/50 and 65/35 Copolymers", IEEE Trans. on Ultrasonics, Ferroelectrics and Frequency Control, 47 (6), 1296-1307, Nov 2000.
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