Effect of Temperature and Concentration on the Optical Properties of PVC Solutions (original) (raw)
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Doping Effect on Optical Constants of Poly-Vinyl Chloride (PVC)
Academic Research International
In the present work, the effect of silver acetic ((CH3COO) Ag) addition on some optical properties of poly-vinyl chloride has been studied. For that purpose, many samples has been prepared by adding ((CH 3COO) Ag) to the poly-vinyl chloride with different weight percentages from ((CH 3COO) Ag) with polymer and by different thickness .The absorption and transmission spectra has been recorded in the wavelength range (190-890) nm. The absorption coefficient, refractive index, extinction coefficient, real and imaginary dielectric constant and optical conductivity have been determined.
Optical properties of pure and modified poly(vinyl chloride)
International Journal of Industrial Chemistry, 2013
Background: In this study, poly(vinyl chloride) (PVC) is considered one of the most versatile plastics. It is the second largest manufactured resin by volume worldwide. Results: To study the optical properties of modified PVC containing 1,3,4-thiadiazole and phthalyl groups in the repeating units, thin films of the prepared polymers (P I, P II, P III, P IV, P V, and PVC) were casted from tetrahydrofuran solvent with a thickness of 30 μm. The optical properties were studied in the range of 200 to 600 nm, and the optical data were analyzed and interpreted in terms of the theory of phonon-assisted direct electronic transitions; the measured E g of pure and modified PVC increases in the following order:
Optical properties and structural features of UV-C irradiated polyvinylidene chloride films
The modifications caused in polyvinylidene chloride (PVDC) polymer films on exposure to ultra-violet light (UV-C light of wavelength 254 nm) in air for different exposure times varying from one hour up to six hours have been investigated by using ultraviolet - visible (UV-Vis) and Fourier transform infrared (FTIR) spectroscopic techniques, as well as powder X-ray diffraction (XRD) technique. XRD scans reveal that the degree of crystallinity (Xc) increased from 4.7% up to 28.6% on increasing the UV exposure time of PVDC from 1 hour up to 4 hours, and a further increase in the exposure time causes a decrease in the value of Xc. The FTIR scans reveal the formation of hydrogen bonded hydroxyl groups as well as conjugated alkene structures in the PVDC sample on exposure to UV-C radiation. For the study of modification in band structure of the UV irradiated PVDC films, the UV-Vis spectroscopy was used; it was found that the optical band gap decreases from 4.70 eV down to 3.92 eV, as obtai...
The tendency to improve the properties of insulating materials by incorporating inorganic nanoparticles has become necessary in order to design new insulation systems. In this study, PVC/TiO 2-based nanocomposites with different loadings (3, 5 and 10 wt.%) of TiO 2 nanoparticles were prepared by the solution mixing method. The morphology of the prepared nanocomposites was studied by Atomic Force Microscope (AFM). Experimentally, it was found that as the concentration increases, the size of the surface structural elements and particle size increases. Photoluminescence (PL) analysis of samples shows improvement compared to the pristine polymer. Furthermore, PL intensity for nanocomposites increases depending on the concentration and saturation occurs at a certain amount of titanium dioxide nanoparticles. The increase in luminescence intensity till a certain nanoparticle content is due to the growth of the luminescent surface area. Further saturation is explained by the increase in particle size with no increase or a slight reduction in surface area. Dielectric properties of nanocomposites were studied. It was found that dielectric permittivity of the materials increases as the nanoparticle volume content increases and it reaches at its highest value for the nanocomposites with 3% nanoparticle content. The optical properties of the polymer and nanocomposite films were studied in the region 200 nm to 600 nm. It was found that the PVC/TiO 2 nanocom-posites showed enhancement in the absorbance intensities which was more significant for the nanocomposites with higher nanoparticle content compared to the pristine polymer. Furthermore, absorption spectra were used to calculate the optical bandgap of the prepared nanocomposite films and redshift observed in the calculated values of bandgap for nanocomposites. Consequently, it was proved that by incorporating TiO 2 nanoparticles into the polymer matrix, the spectral region of the samples can be expanded resulting in broadened application of such systems in various fields of science and technology.
Optical and Electrical Properties of Polyvinyl-Chloride (PVC) Films
Iraqi journal of science, 2010
In-situ technique is used to generate cadmium sulfide nanoparticles in PVA matrix. The as-prepared films are characterized by X-ray diffraction, transmission electron microscopy, ultraviolet-visible absorption, Fourier transform infrared spectroscopy and photoluminescence measurements. Temperature dependence dark conductivity measurements are made on as-deposited PVA:n-CdS nanocomposites films in order to identify the conduction mechanism. The conduction in PVA:n-CdS nanocomposites films is temperature activated process having single activation energy. Steady state photo-conductivity and transient photoconductivity measurements with intensity are done in different temperature range. The measurement shows that PVA doped CdS is good candidate for photovoltaic devices.
Optical Properties of Poly Vinyl Chloride PVC Films Irradiated with Beta and Gamma -Rays
2012
The effect of β and γ radiation on optical constants and the optical energy gap Eg of polyvinyl chloride PVC films casted with different thickness is presented. On the basis of quantitative analysis of obtained data, the calculated refractive index n, extinction coefficient k, real and imaginary parts of dielectric constants e1, and e2are found to increases with irradiation and thickness. The results show the effect of γ radiation on n valued is thickness independent while that for β radiation is thickness dependent, while k, e 1, and e 2 are found radiation and thickness dependent. The optical energy gap Eg values of unirradiated and irradiated PVC samples are found to change in contrast manner with that of the optical activation energy Ee .The results are discussed on the basis of the radiation induced crosslinking of PVC samples.
International Journal of Engineering Research and Technology (IJERT), 2020
https://www.ijert.org/concentration-temperature-and-molecular-weight-dependent-on-optical-properties-of-poly-vinyl-pyrrolidone-in-chloroform-solutions https://www.ijert.org/research/concentration-temperature-and-molecular-weight-dependent-on-optical-properties-of-poly-vinyl-pyrrolidone-in-chloroform-solutions-IJERTV9IS070139.pdf We report on the concentration, temperature and molecular weight dependent of some optical properties of poly(vinyl pyrrolidone), PVP dissolves in chloroform for different molecular weights (25k, 44k and 700k) at different concentrations (0.1-10w/v%) with temperature range (25-45°C). Refractive index has been measured to determine the optical parameters including, reflectance, coefficient of fineness and critical angle. The results show that refractive index, reflectance and coefficient of fineness values increased with increasing concentration and molecular weight, whereas the temperature had a different influence. However, theses parameters were decreased with increasing the temperature. On the other hand, critical angle values the results presented that the refractive index, reflectance, and coefficient of fineness of the polymer decreases with increasing the temperature while the critical angle has the revers behavior.
UV-Induced Electrical and Optical Changes in PVC Blends
Monatshefte fuer Chemie/Chemical Monthly, 2001
2-Chloro-polyaniline (2-Cl-PANI) in its non-conducting (emeraldine base, EB) form, prepared by a chemical route, was dissolved together with poly-(vinylchloride) (PVC) in THF for casting into thin (10±50 mm) ®lms. Upon exposure to UV radiation, the electrical conductivity of these ®lms increased by more than 4 orders of magnitude (from 10 À6 to 10 À2 Sacm). This is attributed to the dehydrochlorination of PVC by exposure to energetic photons and subsequent doping of 2-Cl-PANI (i.e. conversion to emeraldine salt, ES) by in situ created HCl. The doped ®lms could be returned to their undoped form by exposure to NH 3 vapours. The UV-induced doping/NH 3 undoping cycles could be repeated several times. Various spectroscopic techniques were employed to follow the changes in the ®lms upon exposure to UV radiation. The same photo-dehydrochlorination process has also been utilized for optical and/or lithographic purposes by preparing PVC blends containing methyl violet, and acid-base indicator dye. The photo-dehydrochlorination can be effectively sensitized by incorporating hydroquinone into the PVC blends containing methyl violet.
Diyala Journal For Pure Science, 2020
In this study, the effects of temperature on the absorption and emission spectra of polyvinyl chloride films were investigated in the presence of diethyl phthalate as a quencher. In this paper, diethyl phthalate (DEP) was used as a quencher at different concentrations to study its effect on the behavior of absorption and emission spectra in the wavelength range from 200 to 350 nm. The films have been treated thermally at 25, 40, 50 and 60 o C. The results showed that the absorption spectrum contains two absorption bands for all samples. The first absorption band appeared in the range of 200 to 220 nm. The maximum absorption band was shifted towards red wavelengths depending on the concentration and temperature. The second absorption band appeared from 260 to 300 nm was weak, broad and unaffected by a concentration while showing a simple response to temperature without displacement in the maximum absorption (λmax.). The changes in absorbance as a function of quencher concentration at room temperature (25 o C) are illustrated.
Spectroscopic investigation of polyvinyl chloride photodegradation in blends with basic traps
1999
Polyvinyl chloride degrades via loss of HCI when it is exposed to heat, energetic particles or photons. The mechanism is known as the zip mechanism and results in conjugated segments, polyenes. Degradation also leads to loss of mechanical properties of PVC. However, from another point of view, PVC is a Bronsted acid source, with controllable emission. Furthermore, the polyenes are small segments of polyacetylene, which itself is a very interesting one-dimensional system. Understanding the building blocks clearly helps to envisage larger systems. This study has two main goals. The first goal is benefiting from the radiation induced in-situ created HCI by incorporating basic traps into the polymer matrix and inducing optical or electrical conductivity changes. The second goal is to tune the wavelength of photodegradation by introducing sensitisers into the polymer matrix to affect the chain length of the polyenes.