Characterization and Optical and Dielectric Properties of Polyvinyl Chloride/Silica Nanocomposites Films

Abdel-Baset, T.; Elzayat, M.; Mahrous, S.

doi:https://doi.org/10.1155/2016/1707018

International Journal of Polymer Science

On this page

Abstract Introduction Results Conclusions References Copyright Related Articles

Research Article | Open Access

Volume 2016 | Article ID 1707018 | https://doi.org/10.1155/2016/1707018

Characterization and Optical and Dielectric Properties of Polyvinyl Chloride/Silica Nanocomposites Films

T. Abdel-Baset,¹M. Elzayat,¹and S. Mahrous¹

Academic Editor: Yulin Deng

Received20 Jan 2016

Revised19 Apr 2016

Accepted11 May 2016

Published03 Jul 2016

Abstract

Silica nanoparticles were synthesized by a sol-gel method and mixed with different amounts of polyvinyl chloride (PVC) to get nanocomposite films. The samples were characterized by XRD, HR-TEM, SEM, and FTIR. High resolution transmission electron microscopy (HR-TEM) proved that the average particle size of the nanosilica is 15 nm. The scanning electron microscopy (SEM) showed that the nanosilica was well dispersed on the surface of the PVC films. Fourier Transform Infrared (FTIR) spectra for nanocomposite films intimate a significant change in the intensity of the characteristic peaks of the functional group with addition of nanosilica. The optical band gap was found to decrease with the addition of nanosilica while the refractive index increased. The dielectric constant , the dielectric loss modulus , and AC conductivity were also studied. It was found that increases with temperature for all samples, clear dielectric -relaxation observed from dielectric loss around the glass temperature (), and this could be related to micro-Brownian motion of the main PVC chain. The activation energy was calculated, and the AC conductivity could be a hopping one. The results of this work are discussed and compared with previously obtained data.

1. Introduction

Polymer nanocomposite, particularly polyvinyl chloride (PVC) based material, attracted worldwide attention due to its industrial applications and academic interests [1–3]. In fact, there are many reports on different PVC based nanocomposites [4–10].

Silica nanoparticles are extensively studied for many applications such as photonic crystals [11, 12], chemical sensors [13], biosensors [14], nanofillers for advanced composite materials [15–17], markers for bioimaging [18], substrate for quantum dots [19, 20], and catalysts [21, 22]. However many interesting reports indicated the uses of silica in the formation of modern polymer composites, such as poly(butylene terephthalate) (PBT) [23], poly(methyl acrylate) (PMA) [24], polyethylene (PE) [25], polypropylene (PP) [26], polystyrene (PS) [27], polyhydroxyethylmethacrylate (PHEMA) [28], polyurethane (PUR) [29], natural rubber [30], and acrylonitrile-butadiene elastomer (NBR) [31]. Motivation for the use of silica as a polymer filler comes primarily from its high thermal stability and the favorable strength properties of the resulting composites.

The mechanical properties and process ability of PVC filled with nano-SiO₂ particles are widely investigated [32, 33]. It is noteworthy that the incorporation of nanosized silica into PVC-polymer gives rise to new types of nanocomposite polymer electrolytes. Generally, extensive research is still under processing on the mechanical and process ability properties of PVC composites filled with inorganic nanoparticles and on the dispersion of inorganic particles in polymeric matrix. However, there is a notable dearth of information with respect to the optical and dielectric properties of this composite.

It seems that much more investigations of quantitative characterization of its effective interfacial interactions are required. So, it seems essential to investigate both optical properties and interfacial interactions of PVC composites filled with inorganic nanoparticles. The most important parameter governing the utilization of silica nanoparticles in the research work is the optical properties. The transparency and refractive index are important optical properties of polymer nanocomposite. From all the above we investigated the effect of the addition nanosilica to PVC matrix into the optical and dielectric properties of the nanocomposite films.

2. Experimental Work

2.1. Materials and Methods

2.1.1. Synthesis of SiO₂ Nanoparticles

Silica nanoparticles were synthesized via a sol-gel method. A desired amount of sodium silicate solution (Na₂SiO₃) with molecular weight of 122.06 (Sigma-Aldrich) was diluted with distilled water under stirring for 15 min, and diluted hydrochloric acid was used to precipitate it. The precipitate was filtered and washed several times with distilled water until complete removal of sodium chloride. This precipitate was dried in air overnight.

2.1.2. Preparation of PVC/SiO₂ Nanocomposite

Different concentrations (1, 2, and 4 wt.%) of the synthesized SiO₂ nanoparticles were added to PVC (Polymer Laboratories, Essex, UK) according to the relation where and represent the weights of SiO₂ and PVC, respectively. We get the nanocomposite films through the following steps: 1 g of PVC was dissolved in 25 mL tetrahydrofuran (THF, Aldrich, Germany) with stirring until a transparent solution was watched. The calculated weight of the prepared SiO₂ nanoparticles was added to the solution under ultrasonic stirrer at room temperature (RT) for 30 min to prevent the agglomeration of the nanoparticles. The different solutions of the mixtures were then casted in Petri dishes and kept for 24 h to dry in air at RT.

2.1.3. Characterization Techniques

X-ray diffraction (XRD) was used to characterize the sensitized SiO₂ powder, the films of pure PVC, and the films of PVC loaded with SiO₂ nanoparticles. Analysis of the samples was achieved using a Rigaku miniflex diffractometer with CuK radiation ( = 1.5406 Å). The particle size of the as-synthesized nanosilica was determined using high resolution transmission electron microscopy (HR-TEM; JEM 2100, JEOL, Japan). Scanning electron microscopy (SEM; Inspect S, FEI, Holland) images were taken for the nanocomposite films. The FTIR spectra were taken using a Shimadzu 8201 PC spectrophotometer in the range of 4000–400 cm⁻¹. A Shimadzu UV-3600 UV-VIS-NIR spectrophotometer was used to study optical characterization in the wavelength range of 200–850 nm. LCR meter (model 3532, HIOKI, Ueda, Nagano, Japan) was used to investigate the temperature dependence of the dielectric characterization. A T-type thermocouple was used to measure the temperature (with an accuracy of 1°C).

3. Results and Discussions

3.1. X-Ray Diffraction

X-ray diffraction spectra of pure PVC, pure SiO₂ nanoparticles, and 4 wt% PVC-SiO₂ nanocomposite films are shown in Figure 1. The amorphous nature of the nanosilica was clearly observable, consistent with previous reports [34, 35]. Also, the amorphous nature of pure PVC is indicated through a broad peak in the region of 15–30° [36]. Moreover the spectra for the composite intimate a wide and shallow peak, suggesting an amorphous structure of the nanocomposite. This shows that the addition of silica nanoparticles causes a decrease in the degree of crystallinity and a simultaneous increase in the amorphicity of the composite.

3.2. Characterization

The average size and shape of the as-prepared SiO₂ nanoparticles were tested through HR-TEM image. It can be seen from Figure 2(a) that the average particle size is about 15 nm. Also, SEM was used to examine the morphology and dispersion of SiO₂ nanoparticles on the surface of PVC films. Figures 2(b) and 2(c) show the SEM images of selected nanocomposite films, showing a good dispersion of SiO₂ on the surface of the PVC films. This proves the validity of our synthesis process for obtaining nanosilica.

3.3. FTIR Spectroscopy

Figure 3 shows the FITR spectra for the nanocomposite films. The characteristic peaks of the saturated C–H groups on PVC chains appeared at 2970–2800 cm⁻¹, 1428 cm⁻¹, and 1327 cm⁻¹ absorption. For both the pure PVC and PVC-SiO₂ nanocomposite films, C–H band at 2953 cm⁻¹ appeared. Unexpectedly, C–H band at 2907 cm⁻¹ surpasses the band at 2953 cm⁻¹, which might be due to the presence of isooctyle groups on the surface. The peaks at 695 cm⁻¹ and 615 cm⁻¹ are attributed to C–Cl bond stretching [36]. The observed peak at 1250 cm⁻¹ is attributed to the C–C swing vibration in the group CH₂–CHCl. Also, at 945 cm⁻¹ an absorption peak is seen which could be related to the Si–OH group (Si–O– stretching). At about 797 and 1095 cm⁻¹, the absorption peaks are initiated by Si–O–Si symmetric and asymmetric stretching vibration, respectively, demonstrating the generation of Si–O–Si in the system [37]. Usually, the long-range coupling Coulomb interactions cause the splitting of the peak of the Si–O–Si asymmetric stretching vibration into two components: a transverse optical (TO) and a longitudinal optical (LO) component. The peak close to 1095 cm⁻¹ has been generally caused by the TO component, whereas the shoulder at 1186 cm⁻¹ under the peak of 1095 cm⁻¹ is denoted as the LO component [38]. The absorption peak at about 1000–1430 cm⁻¹ is related to the overlap of Si–O–Si (1000–1100 cm⁻¹), Si–O–C (1080–1120 cm⁻¹), and C–O–C (1000–1300 cm⁻¹). The observed FTIR data are in good agreement with the results of [39].

Also, as is seen in Figure 3, the FTIR bands of PVC-SiO₂ nanocomposite films intimate a regular increase in the intensity of the absorption peaks with SiO₂ particle loading. This was related to the formation of bonds between the constituents of the composite materials.

3.4. Optical Properties

3.4.1. Optical Band Gap and Urbach Energies for and PVC-SiO₂ Nanocomposite Films

The optical behavior of materials is described by optical constants. Figure 4(a) shows the absorbance spectra of pure PVC and PVC-SiO₂ nanocomposite films. It is obvious that the absorbance increases with increasing SiO₂ nanoparticles ratio in PVC-SiO₂ nanocomposite. As is known, PVC is transparent in the visible region. This is clearly shown in Figure 4(b), while the transmittance decreases in the PVC-SiO₂ nanocomposite sample. It is known that sol-gel method causes many lattice defects in the silica, resulting in a decrease in the transparency of the nanocomposite with increasing nano-SiO₂ content. The formula ( = absorbance/films thickness) was used to calculate the dependence of the absorption coefficient () on frequency. The optical band gap () is determined by Tauc’s relation [40, 41]:where is the incident photon energy, is the probability parameter for transition, and adopts being 1/2 and 2 for allowed direct and allowed indirect transitions [42], respectively. The direct band gaps were obtained from the plots of ()² versus at RT as shown in Figure 5, and the values were estimated by extrapolating the linear part of ()² to zero. The obtained values are given in Table 1. It was found that the values decrease with the addition of nanosilica which indicates that the position of the electronic band gap of the nanocomposite depends on the concentration of SiO₂ on it.

(a)

(b)

The absorption coefficient near the fundamental absorption edge is exponentially dependent on and obeys the empirical Urbach relation. The Urbach energy (), which is the width of the tails states in the band gap associated with the structural defects and disorder within the polymer matrix, can be calculated by the relation [43]where is the absorption coefficient as a function of the photon energy () and and are constants determined from versus plot (Figure 6). approximately coincides with the energy of the lowest free exciton state at zero temperature. The value of was obtained from the inverse of the slope of versus , and the obtained values are listed in Table 1. The values change inversely with optical band gap. The increase of suggests that the atomic structural disorder of PVC increases by nanosilica doping; this increase would lead to a redistribution of states, from band to tail, thus allowing for a greater number of possible bands-to-tail and tail-to-tail transitions [44]. is often interpreted as the width of the tail of localized states in the gap region associated with the tailing of the valance band density of states and is broader than the conduction band tail.

3.4.2. Refractive Index Dispersion of Pure PVC and PVC/SiO₂ Nanocomposite Films

The refractive index () could be calculated using the reflectance () and the extinction coefficient, , (where ) of films as follows [44]:where is the reflectance calculated from the absorbance () and transmission () spectra [44].

Figure 7 shows the refractive index distributions of pure PVC and PVC-SiO₂ nanocomposite films. The refractive index are found to increase with the addition of SiO₂ nanoparticles. Such increase in may extend the usability of these materials as antireflection coating.

We used the Wemple-DiDomenico model describes that the dielectric response for transitions below the optical gap was used to calculate the single-oscillator parameters. The dispersion data of the refractive index can be described by a single-oscillator model, where and are single-oscillator constants [45]: is the single-oscillator energy and is the dispersion energy which measures the average strength of interband optical transition, and values can be determined as the slope and the intercept of Figure 8, according to (5), and the obtained values are listed in Table 1. It is found that ; this result agrees with the single-oscillator model [45].

3.5. Dielectric Properties

3.5.1. Dielectric Permittivity

The dielectric behavior of polymer nanocomposite materials is a powerful technique for studying the relaxation and conduction mechanisms in polymeric materials [46].

Figure 9 displays the temperature dependence of at selected frequencies for pure PVC and PVC-SiO₂ nanocomposite films. It is shown that varies slowly with increasing the temperature up to and then increases with further increase in temperature till reaching a saturation region and then it decreases again. The relaxation process observed near the glass transition temperature for the prepared nanocomposite (-relaxation) is attributed to the cooperative dipolar orientations. This relaxation process corresponds to the segmental relaxation associated with the glass transition at which the micro-Brownian motion of long chain segments in the amorphous regions of PVC [47].

(a) Pure PVC

(b) 1 wt.% NS

(c) 2 wt.% NS

(d) 4 wt.% NS

At lower temperatures, the thermal energy that is absorbed by the polymeric material, at a certain fixed frequency, is small and a small number of dipoles can rotate with small angles. With increasing temperatures, value is determined by the number of orienting dipoles per unit volume and their dipole moments [46]. As the temperature increased, the viscosity of polymeric films is decreased and the dipoles gain sufficient energy and can orient themselves easily in the direction of the applied electric field; thus increase with increasing temperatures. Also, the chain segments get sufficient thermal energy to speed up its rotational motion and consequently polarization increases [48]. However, the specific volume of the polymer increases with the further increase in temperature, and hence value is increased at higher temperatures [49, 50].

It is also clear that decreases with the increase of frequencies for all samples. The decreases may be attributed to the decreasing of the number of dipoles, which contribute to polarization, or dipole structure is no longer able to respond to the applied electric field; this leads to reduction in the value.

Moreover, seems to decrease to lower values after adding the nanosilica to PVC matrix. Silica nanoparticles have more surface area whose effect combined with the resulting change in PVC morphology and the space charge distribution leads to reduction in the internal field. This reduction could be the cause of the reduction for pure PVC and PVC-SiO₂ nanocomposite films.

3.5.2. Electric Modulus

At low frequencies and high temperatures the observed values of dielectric permittivity do not refer to the bulk of the material; this is related to the so-called “interfacial polarization” dominant in these composites polymeric materials [51]. To avoid contributing of the interfacial polarization, the modulus formalism can be used for analyses of the dielectric behavior of PVC. In addition, the recorded dielectric data can be expressed in terms of the complex electric modulus () [52], which is defined as the inverse of the complex permittivity ():where and are the real and imaginary parts of the dielectric modulus, respectively. Figures 10(a)–10(d) show the temperature dependence of for PVC and PVC-SiO₂ nanocomposite films at different frequencies; it is observed that the values of decrease with increasing temperatures for pure PVC and PVC-SiO₂ nanocomposite films; at high temperatures tends to reach a constant value indicating the removal of the electrode polarization for the investigated samples owing to thermally activated nature of dielectric constant [52].

(a) Pure PVC

(b) 1 wt.% NS

(c) 2 wt.% NS

(d) 4 wt.% NS

The temperature-dependent behavior of for pure PVC and PVC-SiO₂ nanocomposite films at different frequencies is displayed in Figure 11. The spectrum shows asymmetric peak corresponding to -relaxation process which is related to the micro-Brownian motion in the amorphous region of the main polymer chain [47]. The peaks shift to higher temperatures with increasing frequency because the increase of temperature releases more dipoles; hence the density of dipoles contributing the relaxation process increases with increasing temperature. The region to the left of peak is where the dipoles rotate faster, and the region to the right is where the dipoles are spatially confined to their equilibrium positions.

(a) Pure PVC

(b) 1 wt.% NS

(c) 2 wt.% NS

(d) 4 wt.% NS

3.5.3. The AC Conductivity

To investigate the influence of adding the silica nanoparticles on the AC conductivity () for pure PVC and PVC-SiO₂ nanocomposite films, the values were calculated using the relation (), where is the angular frequency, is the permittivity of the free space, and represents the dielectric loss. The activation energy () for all samples was calculated according to the Arrhenius relation [53]: . Figures 12(a)–12(d) represent the measured ac conductivity () as a function of the reciprocal of temperature (1000/) for pure PVC and PVC-SiO₂ nanocomposite films. It is clear that for each sample increases with increasing the applied frequency. This may be due to the increase of the absorbed energy which leads to increase of the number of the charge carriers that contribute to the conduction process. These observations agreed with the published data for different polymers and amorphous nanoparticles [53–55].

(a) Pure PVC

(b) 1 wt.% NS

(c) 2 wt.% NS

(d) 4 wt.% NS

The values of for all investigated samples at = 60 kHz to 2 MHz and their corresponding temperature range (300 K ≤ ≤ 370 K) are summarized in Table 2. We show that the values of for PVC are decreased with increasing the content of silica nanoparticles; moreover the increase of with temperature may have been caused by an increase in the absorbed energy, which leads to an increase in the number of charge carriers that contribute to the conduction process. This reveals that the conduction mechanism could be a hopping one [56]. Also, the variation of the conductance with temperature can be attributed to a combined effect of the change in the conductance with temperature and to the nature of the trap distribution inside the polymer networks.

4. Conclusions

Silica nanoparticles with an average particle size of 15 nm were successfully prepared and used for synthesis of PVC/SiO₂ nanocomposite films with 1, 2, and 4 wt% silica. It is found that the PVC-silica nanocomposite films were homogenous. The XRD analysis indicated that both the prepared silica nanoparticles and PVC-SiO₂ nanocomposite films have amorphous nature. The values of the optical band gap and Urbach energy were calculated using the optical method. The optical band gap was found to decrease with addition of nanosilica, while the Urbach energy values change inversely with optical band gap. The dispersion curves of the refractive index obey the single-oscillator model. The refractive index increased by increasing the silica nanoparticles content. These results may suggest the important applications of these nanocomposite films as optical devices.

The dielectric constant increase with increasing temperatures and the -relaxation obtained around due to micro-Brownian motion were observed on the dielectric loss behavior. The temperature dependence behavior of the AC conductivity indicated that the conduction mechanism for all samples could be hopping. The activation energy for all samples was found to be decrease with addition of nanosilica; these results could be helpful for many applications of the nanocomposite films.

Competing Interests

The authors declare that they have no competing interests.

References

S. Cho and W. Choi, “Solid-phase photocatalytic degradation of PVC–TiO₂ polymer composites,” Journal of Photochemistry and Photobiology A: Chemistry, vol. 143, no. 2-3, pp. 221–228, 2001.
View at: Publisher Site | Google Scholar
B. J. Ash, R. W. Siegel, and L. S. Schadler, “Glass-transition temperature behavior of alumina/PMMA nanocomposites,” Journal of Polymer Science, Part B: Polymer Physics, vol. 42, no. 23, pp. 4371–4383, 2004.
View at: Publisher Site | Google Scholar
M. W. Pan, X. D. Shi, X. C. Li, H. Y. Hu, and L. C. Zhang, “Morphology and properties of PVC/clay nanocomposites via in situ emulsion polymerization,” Journal of Applied Polymer Science, vol. 94, no. 1, pp. 277–286, 2004.
View at: Publisher Site | Google Scholar
I. S. Elashmawi, N. A. Hakeem, L. K. Marei, and F. F. Hanna, “Structure and performance of ZnO/PVC nanocomposites,” Physica B: Condensed Matter, vol. 405, no. 19, pp. 4163–4169, 2010.
View at: Publisher Site | Google Scholar
A. Olad and R. Nosrati, “Preparation and corrosion resistance of nanostructured PVC/ZnO-polyaniline hybrid coating,” Progress in Organic Coatings, vol. 76, no. 1, pp. 113–118, 2013.
View at: Publisher Site | Google Scholar
W. E. Mahmoud and A. A. Al-Ghamdi, “The influence of Cd(ZnO) on the structure, optical and thermal stabilities of polyvinyl chloride nanocomposites,” Polymer Composites, vol. 32, no. 7, pp. 1143–1147, 2011.
View at: Publisher Site | Google Scholar
F. Liu, H. Liu, X. Li et al., “Nano-TiO₂@Ag/PVC film with enhanced antibacterial activities and photocatalytic properties,” Applied Surface Science, vol. 258, no. 10, pp. 4667–4671, 2012.
View at: Publisher Site | Google Scholar
A. Olad, S. Behboudi, and A. A. Entezami, “Effect of polyaniline as a surface modifier of TiO₂ nanoparticles on the properties of polyvinyl chloride/TiO₂ nanocomposites,” Chinese Journal of Polymer Science, vol. 31, no. 3, pp. 481–494, 2013.
View at: Publisher Site | Google Scholar
O. A. Al-Hartomy, F. Al-Salamy, A. A. Al-Ghamdi, M. Abdel Fatah, N. Dishovsky, and F. El-Tantawy, “Influence of graphite nanosheets on the structure and properties of PVC-based nanocomposites,” Journal of Applied Polymer Science, vol. 120, no. 6, pp. 3628–3634, 2011.
View at: Publisher Site | Google Scholar
A. A. Al-Ghamdi, F. El-Tantawy, N. Abdel Aal, E. H. El-Mossalamy, and W. E. Mahmoud, “Stability of new electrostatic discharge protection and electromagnetic wave shielding effectiveness from poly(vinyl chloride)/graphite/nickel nanoconducting composites,” Polymer Degradation and Stability, vol. 94, no. 6, pp. 980–986, 2009.
View at: Publisher Site | Google Scholar
A. Chiappini, C. Armellini, A. Chiasera et al., “Design of photonic structures by sol-gel-derived silica nanospheres,” Journal of Non-Crystalline Solids, vol. 353, no. 5–7, pp. 674–678, 2007.
View at: Publisher Site | Google Scholar
L. Pallavidino, D. S. Razo, F. Geobaldo et al., “Synthesis, characterization and modelling of silicon based opals,” Journal of Non-Crystalline Solids, vol. 352, no. 9–20, pp. 1425–1429, 2006.
View at: Publisher Site | Google Scholar
C. T. Wang, C. L. Wu, I. C. Chen, and Y. H. Huang, “Humidity sensors based on silica nanoparticle aerogel thin films,” Sensors and Actuators B: Chemical, vol. 107, no. 1, pp. 402–410, 2005.
View at: Publisher Site | Google Scholar
S. A. Grant, C. Weilbaecher, and D. Lichlyter, “Development of a protease biosensor utilizing silica nanobeads,” Sensors and Actuators, B: Chemical, vol. 121, no. 2, pp. 482–489, 2007.
View at: Publisher Site | Google Scholar
H. Wang, Y. Bai, S. Liu, J. Wu, and C. P. Wong, “Combined effects of silica filler and its interface in epoxy resin,” Acta Materialia, vol. 50, no. 17, pp. 4369–4377, 2002.
View at: Publisher Site | Google Scholar
H. Zhang, Z. Zhang, K. Friedrich, and C. Eger, “Property improvements of in situ epoxy nanocomposites with reduced interparticle distance at high nanosilica content,” Acta Materialia, vol. 54, no. 7, pp. 1833–1842, 2006.
View at: Publisher Site | Google Scholar
S.-C. Kwon, T. Adachi, W. Araki, and A. Yamaji, “Thermo-viscoelastic properties of silica particulate-reinforced epoxy composites: Considered in terms of the particle packing model,” Acta Materialia, vol. 54, no. 12, pp. 3369–3374, 2006.
View at: Publisher Site | Google Scholar
P. Sharma, S. Brown, G. Walter, S. Santra, and B. Moudgil, “Nanoparticles for bioimaging,” Advances in Colloid and Interface Science, vol. 123–126, pp. 471–485, 2006.
View at: Publisher Site | Google Scholar
L. Jiang, W. Wang, D. Wu et al., “Preparation of silver quantum dots embedded water-soluble silica/PAAc hybrid nanoparticles and their bactericidal activity,” Materials Chemistry and Physics, vol. 104, no. 2-3, pp. 230–234, 2007.
View at: Publisher Site | Google Scholar
C.-Y. Lai, C.-W. Wu, D. R. Radu, B. G. Trewyn, and V. S.-Y. Lin, “Reversible binding and fluorescence energy transfer between surface-derivatized CdS nanoparticles and multi-functionalized fluorescent mesoporous silica nanospheres,” Studies in Surface Science and Catalysis, vol. 170, pp. 1827–1835, 2007.
View at: Publisher Site | Google Scholar
G. Neri, G. Rizzo, C. Crisafulli et al., “Isomerization of α-pinene oxide to campholenic aldehyde over Lewis acids supported on silica and titania nanoparticles,” Applied Catalysis A: General, vol. 295, no. 2, pp. 116–125, 2005.
View at: Publisher Site | Google Scholar
J. L. Gole, C. Burda, Z. L. Wang, and M. White, “Unusual properties and reactivity at the nanoscale,” Journal of Physics and Chemistry of Solids, vol. 66, no. 2–4, pp. 546–550, 2005.
View at: Publisher Site | Google Scholar
T. Jesionowski, K. Bula, J. Janiszewski, and J. Jurga, “The influence of filler modification on its aggregation and dispersion behaviour in silica/PBT composite,” Composite Interfaces, vol. 10, no. 2-3, pp. 225–242, 2003.
View at: Publisher Site | Google Scholar
W. Brostow, T. Datashvili, and K. P. Hackenberg, “Synthesis and characterization of poly(methyl acrylate) + SiO₂ hybrids,” E-Polymers, vol. 8, no. 1, pp. 608–620, 2008.
View at: Google Scholar
Y. Bolbukh, P. Kuzema, V. Tertykh, and I. Laguta, “Thermal degradation of polyethylene containing antioxidant and hydrophilic/hydrophobic silica,” Journal of Thermal Analysis and Calorimetry, vol. 94, no. 3, pp. 727–736, 2008.
View at: Publisher Site | Google Scholar
T. H. Zhou, W. H. Ruan, Y. L. Mai, M. Z. Rong, and M. Q. Zhang, “Performance improvement of nano-silica/polypropylene composites through in-situ cross-linking approach,” Composites Science and Technology, vol. 68, no. 14, pp. 2858–2863, 2008.
View at: Publisher Site | Google Scholar
W. H. Zhang, X. D. Fan, W. Tian, and W. W. Fan, “Polystyrene/nano-SiO₂ composite microspheres fabricated by Pickering emulsion polymerization: Preparation, mechanisms and thermal properties,” eXPRESS Polymer Letters, vol. 6, no. 7, pp. 532–542, 2012.
View at: Publisher Site | Google Scholar
Y. Bolbukh, V. Tertykh, P. Klonos, and P. Pissis, “DSC study of polyhydroxyethylmethacrylate filled with modified silicas,” Journal of Thermal Analysis and Calorimetry, vol. 108, no. 3, pp. 1111–1119, 2012.
View at: Publisher Site | Google Scholar
M. Estevez, J. R. Rodriguez, S. Vargas, J. A. Guerra, W. Brostow, and H. E. H. Lobland, “Scratch and abrasion properties of polyurethane-based micro- and nano-hybrid obturation materials,” Journal of Nanoscience and Nanotechnology, vol. 13, no. 6, pp. 4446–4455, 2013.
View at: Publisher Site | Google Scholar
S. Y. Yang, L. Liu, Z. X. Jia, W. W. Fu, D. M. Jia, and Y. F. Luo, “Study on the structure-properties relationship of natural rubber/SiO₂ composites modified by a novel multi-functional rubber agent,” eXPRESS Polymer Letters, vol. 8, no. 6, pp. 425–435, 2014.
View at: Publisher Site | Google Scholar
M. Maciejewska and M. Zaborski, “Effect of ionic liquids on the dispersion of zinc oxide and silica nanoparticles, vulcanisation behaviour and properties of NBR composites,” Express Polymer Letters, vol. 8, no. 12, pp. 932–940, 2014.
View at: Publisher Site | Google Scholar
F. A. Al-Sagheer and Z. Ahmad, “PVC-silica hybrids: effect of sol–gel conditions on the morphology of silica particles and thermal mechanical properties of the hybrids,” Journal of Sol-Gel Science and Technology, vol. 61, no. 1, pp. 229–235, 2012.
View at: Publisher Site | Google Scholar
N. Gharehbash and A. Shakeri, “Modification of the surface of silica nanoparticles; studying its structure and thermal properties in order to strengthen it in preparing nanocomposites,” Journal of American Science, vol. 9, no. 4, pp. 602–606, 2013.
View at: Google Scholar
S. Maheswaran, B. Bhuvaneshwari, G. S. Palani, N. R. Iyer, and S. Kalaiselvam, “An overview on the influence of nano silica in concrete and a research initiative,” Research Journal of Recent Sciences, vol. 2, pp. 17–24, 2013.
View at: Google Scholar
W. E. Mahmoud, “Morphology and physical properties of poly(ethylene oxide) loaded graphene nanocomposites prepared by two different techniques,” European Polymer Journal, vol. 47, no. 8, pp. 1534–1540, 2011.
View at: Publisher Site | Google Scholar
L. Hubert and J. V. Bonilla, Handbook of Plastics Analysis, Marcel Dekker, New York, NY, USA, 2003.
M. Liu, L. Gan, L. Chen et al., “A novel liposome-encapsulated hemoglobin/silica nanoparticle as an oxygen carrier,” International Journal of Pharmaceutics, vol. 427, no. 2, pp. 354–357, 2012.
View at: Publisher Site | Google Scholar
A. Fidalgo and L. M. Ilharco, “The defect structure of sol-gel-derived silica/polytetrahydrofuran hybrid films by FTIR,” Journal of Non-Crystalline Solids, vol. 283, no. 1–3, pp. 144–154, 2001.
View at: Publisher Site | Google Scholar
M. Conradi, M. Zorko, I. Jerman, B. Orel, and I. Verpoest, “Mechanical properties of high density packed silica/poly(vinyl chloride) composites,” Polymer Engineering and Science, vol. 53, no. 7, pp. 1448–1453, 2013.
View at: Publisher Site | Google Scholar
N. Reddeppa, A. K. Sharma, V. V. R. N. Rao, and W. Chen, “Preparation and characterization of pure and KBr doped polymer blend (PVC/PEO) electrolyte thin films,” Microelectronic Engineering, vol. 112, pp. 57–62, 2013.
View at: Publisher Site | Google Scholar
W. E. Mahmoud, A. A. Al-Ghamdi, and F. Al-Agel, “Synthesis and optical properties of poly (vinyl acetate)/bismuth oxide nanorods,” Polymers for Advanced Technologies, vol. 22, no. 12, pp. 2055–2061, 2011.
View at: Publisher Site | Google Scholar
R. Wen, L. Wang, X. Wang, G.-H. Yue, Y. Chen, and D.-L. Peng, “Influence of substrate temperature on mechanical, optical and electrical properties of ZnO:Al films,” Journal of Alloys and Compounds, vol. 508, no. 2, pp. 370–374, 2010.
View at: Publisher Site | Google Scholar
F. Urbach, “The long-wavelength edge of photographic sensitivity and of the electronic absorption of solids,” Physical Review, vol. 92, no. 5, p. 1324, 1953.
View at: Publisher Site | Google Scholar
I. S. Yahia, A. A. M. Farag, M. Cavas, and F. Yakuphanoglu, “Effects of stabilizer ratio on the optical constants and optical dispersion parameters of ZnO nano-fiber thin films,” Superlattices and Microstructures, vol. 53, no. 1, pp. 63–75, 2013.
View at: Publisher Site | Google Scholar
S. H. Wemple and M. DiDomenico, “Behavior of the electronic dielectric constant in covalent and ionic materials,” Physical Review B, vol. 3, no. 4, pp. 1338–1351, 1971.
View at: Publisher Site | Google Scholar
S. Mahrous, “Dielectric analysis of the α-relaxation of PVC stabilized with cadmium laurate,” Polymer International, vol. 40, no. 4, pp. 261–267, 1996.
View at: Publisher Site | Google Scholar
A. Belal, M. Amin, H. Hassan, A. Abd El-Mongy, B. Kamal, and K. Ibrahim, “The role of BaTiO₃ on the dielectric properties of polyvinyl chloride,” Physica Status Solidi (A), vol. 144, no. 1, pp. K53–K57, 1994.
View at: Publisher Site | Google Scholar
T. A. Hanafy, “Dielectric relaxation and alternating-current conductivity of gadolinium-doped poly(vinyl alcohol),” Journal of Applied Polymer Science, vol. 108, no. 4, pp. 2540–2549, 2008.
View at: Publisher Site | Google Scholar
Ch. V. S. Reddy, X. Han, Q.-Y. Zhu, L.-Q. Mai, and W. Chen, “Dielectric spectroscopy studies on (PVP + PVA) polyblend film,” Microelectronic Engineering, vol. 83, no. 2, pp. 281–285, 2006.
View at: Publisher Site | Google Scholar
V. Rao, P. V. Ashokan, and M. H. Shridhar, “Studies of dielectric relaxation and a.c. conductivity in cellulose acetate hydrogen phthalate-poly(methyl methacrylate) blends,” Materials Science and Engineering A, vol. 281, no. 1-2, pp. 213–220, 2000.
View at: Publisher Site | Google Scholar
C. T. Moynihan, L. P. Boesch, and N. L. Laberge, “Decay function for the electric field relaxation in vitreous ionic conductors,” Physics and Chemistry of Glasses, vol. 14, no. 6, pp. 122–125, 1973.
View at: Google Scholar
A. K. Jonscher, Dielectric Relaxation in Soilds, Chelsea Dielectric, London, UK, 1983.
S. El-Sayed, T. Abel-Baset, A. A. Elfadl, and A. Hassen, “Effect of nanosilica on optical, electric modulus and AC conductivity of polyvinyl alcohol/polyaniline films,” Physica B: Condensed Matter, vol. 464, pp. 17–27, 2015.
View at: Publisher Site | Google Scholar
M. D. Migahed, M. Ishra, T. Fahmy, and A. Barakat, “Electric modulus and AC conductivity studies in conducting PPy composite films at low temperature,” Journal of Physics and Chemistry of Solids, vol. 65, no. 6, pp. 1121–1125, 2004.
View at: Publisher Site | Google Scholar
S. A. Saq'an, A. S. Ayesh, A. M. Zihlif, E. Martuscelli, and G. Ragosta, “Physical properties of polystyrene/alum composites,” Polymer Testing, vol. 23, no. 7, pp. 739–745, 2004.
View at: Publisher Site | Google Scholar
S. Yu, P. Hing, and X. Hu, “Dielectric properties of polystyrene-aluminum-nitride composites,” Journal of Applied Physics, vol. 88, no. 1, pp. 398–404, 2000.
View at: Publisher Site | Google Scholar

Copyright

Copyright © 2016 T. Abdel-Baset et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

PDF Download Citation

Download other formats

Order printed copies

Views

4225

Downloads

2744

Citations

International Journal of Polymer Science

Characterization and Optical and Dielectric Properties of Polyvinyl Chloride/Silica Nanocomposites Films

Abstract

1. Introduction

2. Experimental Work

2.1. Materials and Methods

2.1.1. Synthesis of SiO2 Nanoparticles

2.1.2. Preparation of PVC/SiO2 Nanocomposite

2.1.3. Characterization Techniques

3. Results and Discussions

3.1. X-Ray Diffraction

3.2. Characterization

3.3. FTIR Spectroscopy

3.4. Optical Properties

3.4.1. Optical Band Gap and Urbach Energies for and PVC-SiO2 Nanocomposite Films

3.4.2. Refractive Index Dispersion of Pure PVC and PVC/SiO2 Nanocomposite Films

3.5. Dielectric Properties

3.5.1. Dielectric Permittivity

3.5.2. Electric Modulus

3.5.3. The AC Conductivity

4. Conclusions

Competing Interests

References

Copyright

2.1.1. Synthesis of SiO₂ Nanoparticles

2.1.2. Preparation of PVC/SiO₂ Nanocomposite

3.4.1. Optical Band Gap and Urbach Energies for and PVC-SiO₂ Nanocomposite Films

3.4.2. Refractive Index Dispersion of Pure PVC and PVC/SiO₂ Nanocomposite Films