Effect Of Additive Al On the Optical Properties Of Polystyrene-Aluminum Composites Sawsan Abdul Zahra Dept. of Science/ College of Basic Education/University of Al-Mustanisriya Received in :9 September 2012 , Accepted in : 9 December 2012 Abstract Additive aluminum powder to the polystyrene to prepare the composites Polystyrene– Aluminum.The samples were prepared by using mechanical compressed method at low pressure and a temperature 120°C. Measurements of absorbance and reflectance spectra were carried out by UV-Visible spectrophotometer , the effect of additive aluminum on the optical band gap Eop and optical constants ( refractive index n, extinction coefficient k ,dielectric constant ε and optical conductivity σop) were studied for the prepared composites . Results showed a decrease in the Eop with increasing percent of aluminum from 4.1eV for pure polystyrene to about 3.12eV for the composite Ps+30%Al. Values of each of n and k show observable changes, these changes are associated with the increase in scattering, reflection, and optical absorption on the film surface with the increase of Al percentage. The dielectric constant of Ps-Al composites is greater for all Al concentrations and may be attributed to interfacial polarization in the heterogeneous media, it was observed that the optical conductivity increasing from 0.12×105S.cm-1 for pure polystyrene to about 1.32×108S.cm-1 for Ps+30%Al. These results indicate that the optical properties of PS-Al composites can be controlled by the appropriate selection of Al concentration and the optical properties of the composites can be modified by the addition of impurities ,thus increase the industrial application for the composites. Key words: polystyrene, polystyrene composites, optical properties. 111 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 Introduction Composite of inorganic particles with polymers is an interesting research subject because of the important potential application in photo catalytic degradation of polymers, and in fields of adhesives, textiles, optics and electronics .A new class of organic polymers capable of conducting electricity has recently been developed [1, 2]. The concept of the conductive polymer was first present in 1950 [3], these polymers are attractive for electric and photo electronic devices because of their doping capability and advantages of facile processing and become conductive upon partial oxidation or reduction, a process commonly referred to as ‘doping’. These composites consist of a polymer matrix in which a second phase, which is usually either a metal or carbon-based filler, is dispersed, usually by conventional methods of polymer processing [4]. Examples of the conducting polymers are poly (p-styrene, poly aniline, poly (p- phenylenevinylene)-- etc. These polymers can be fabricated to have a high degree of flexibility [5, 6]. Polystyrene is amorphous polymer with bulky side group, general properties are hard ,rigid ,and transparent at room temperature and possesses many of the properties desired for a sensor[7], furthermore ,it has a good charge storage capacity and dopant dependent optical properties, conductivity of the polystyrene can be controlled by the addition of a dopant, which results in a partly filled band and allows it to be easily switched from the “off” to the “on” state. The conductivity of polystyrene composite makes it an ideal shield against static electricity [8]. Polystyrene composites based on Al particles are of great interest due to their ability to combine the inherent processibility of polymers with the electrical conductivity of metals and have been used in a number of applications such as electromagnetic frequency interference (EMI) shields ,and are being tested to use as protection against electromagnetic Radiation, antistatic devices, and conducting coatings [9], because of the technological importance of these composites, their electrical properties have been widely studied [10]. In this paper, we focus on the modification of the optical properties of polystyrene- Al composites by studying the effect of additive Al particles on these properties and to study changes in the optical constants (absorption spectra, optical energy gap, refractive index, dielectric constant and optical conductivity) by using the optical method. Experimental Part Experiments on optical reflectivity and absorbency provide the way to determine the dielectric constant of the solid, which is related to the band structure and to the optical conductivity. The starting materials for the preparation of composite samples were polystyrene powder and Aluminum powder (99.99%) supplied by (Merk, India). For preparing composite samples, a weighed quantity of aluminum powder was first thoroughly mixed with a measured weighed of polystyrene, and the resultant mixture was well mixed so as to obtain a uniform composition, the composite mixture thus obtained was compressed at low pressure 60mpa. and at a temperature of about 120°C, the pressure was maintained for about 3hours. Five samples of Ps-Al composites with Al- varying from (0, 5, 10, 20 and 30 wt%) were prepared in the form of circular disc of radius 10mm and thickness around 0.45±0.08mm measured by using digital vernier. The optical spectra of Polystyrenes-Al composite films were obtained using (Shamindza UV-Vis. Spectroscopy) in the wavelength range 200- 1000nm. 112 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 Theoretical Part Optical methods are very useful for the quantitative determination of the electronic band structure of solids. Complex dielectric constant ε is directly related to the optical properties and characterizes the optical properties of solid material. The complex index of refraction N of the medium is defined as [11]: N √ n ik (1) Where n is the usual refractive index and k is the extinction coefficient, in optical experiments one does not usually measure n and k directly, the measurable quantities are the reflectivity R and the absorption coefficient α. It can be shown that these quantities are related to n and k by the expressions [12] R=|(1-N/1+N)|2 =[(1-n)2 +k2 ] /[(1+n)2 +k2] (2) k =αc/2ω=αλ/4π (3) Where ω=2πυ is the angular frequency of the incident photon & c is the velocity of light, from these expressions n and k can be determined. The dielectric constant is related to the optical conductivity σop by the relation: ε=εl +4πiσop (4) Where εl describes the "bound charges" and σop describes the free charge, in this representation the conduction electrons are considered as a part of the dielectric medium. The real part of dielectric constant is: εr ==n2 -k2 (5) and the imaginary part is: εim =2nk (6) Optical conductivity (σop) is a measure of the frequency response of the composite when irradiated with light and determined from the relation: σop= αnc/4π (7) Results and Discussion Figure(1) illustrates the change in the absorbance A &the reflectance R of polystyrene films under the influence of additive Al, it can be observed that small quantities of Al - impurities added 5% and 10% have no considerable effect on the absorption spectra. The enhanced absorption is observed at 20% and 30% Al content, this suggests the decrease in the band gap with the increase of Al particles, the small absorption peaks appear as an indication that some states have been created in the region between the conduction and the valance band, appearance of a fine absorption spectrum at 30% Al content is due to the presence of discrete energy levels. The absorption coefficient (α) was found experimentally from the relation [13]: α=2.303A /d (8) Where d is the thickness of the film, results showed that the values of α for polystyrene-Al composites are >104 /cm which indicate to the direct electronic transition. The optical absorption coefficient is exponentially dependent on the incident photon energy in the exponent edge, which is strongly related to the structural randomness of the system, and obeys the empirical Urbach rule [14]: α=α o exp (hυ /∆E) ( 9) Where αo is a constant & ∆E is the Urbach energy which is the width of the localized states and can be determined from plotting inα against hυ as shown in figure (2), the values of ∆E for the prepared composites decreased with the increase of Al- content, as given in table (1) this decrease in ∆E is attributed to the impurity levels localized (Al -donor levels) and this could give rise to the allowed states near the conduction band forbidden region, also these allowed states could well merge with the conduction band . 113 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 Values of optical energy gap Eop for pure polystyrene & Ps-aluminum composite have been estimated from (αhυ)2 versus hυ plots using the Mott and Davis model [15] and are shown in figure (3), it can be seen that Eop decrease with the increase of Al content, this trend may be explained as follows, when the aluminum content is low at 5% and 10%, the Al- particles are isolated that is, placed so far apart that there is no interaction between them, as the aluminum content is raised at 20% and 30%, clusters of metal particles are formed, a cluster may be considered as a region in the polymer matrix where metal particles are in physical contact or very close to each other, this means that the band gap is decreased as a result of changes in the molecular mobilities and redistribution of the structure. The variation of energy gap as a function of Al concentration is shown in figure (4), it can be seen that Eop decreased from 4.1eV for pure Polystyrenes to about 3.12eV for Ps+30% Al composite. Our results are in good accordance with the previously published results [16]. The inverse of the absorption coefficient is δ=2/α and known as skin depth, [17], δ is a measure of the distance of penetration optical beam into the medium before the beam is dissipated. In practice, δ has a very small value indicating that an optical beam incident on a specimen penetrates only a short distance below the surface, values of δ at a certain wavelength are given in table (1). Refractive index n is increased with the increase of Al concentration, it can be observed that (n) increases from 1.81 to about 6.42 when the Al-concentration increased from (0 to 30)%, the high values of n is attributed to some complicated polarization and structural defects in polystyrene with the increase of Al- concentration. Extinction coefficient values exhibits clear changes with the increase of Al content, these changes are associated with the increase in scattering, reflection, and optical absorption on the film surface with the increase of Al concentration. Values of refractive index and extinction coefficient at λ=500nm are given in table (1). The behavior of real and imaginary part of dielectric constant with the photon energy is shown in figure (5), compared to pure polystyrene, the dielectric constant of Ps-Al composites is greater for all Al-concentrations and is attributed to interfacial polarization, a phenomenon that appears in heterogeneous media consisting of phases with different conductivity [18], that is, polystyrene-Al composites with aluminum particles dispersed in the polystyrene resin. Ps becomes more heterogeneous as more Al is added to it, because of the formation of accumulation of charges at the interfaces between the dispersed phase and the polystyrene matrix, the sudden change in the relationship between the real part of dielectric constant and Al-concentration at 20% and 30% is attributed to the formation of continuous chains of the conducting phase that spans throughout the polystyrene matrix. The range of variation of dielectric constant is in agreement with the observations of [2,19]. The single oscillator parameters were calculated in terms of the wimple – Didomenico model [20]. This model plays an important role in determining the behavior of the refractive index. The dispersion data of refractive index can be described by the relation: n2-1=Ed-Eo/[Eo2-(hυ)2] (10) Where Eo is single oscillator energy and Ed is the dispersion energy which is a measure of the strength of interband optical transition ,by plotting 1/(n2-1) versus (hυ)2 and fitting line shown in figure (6), Eo and Ed are determined directly from ,the gradient (EoE d )- 1 and the intercept (E o/Ed) on the vertical axis, the values of Eo and Ed decrease with the increase of aluminum content as given in table (1), we found that Eo values is related empirically to the direct band gap by Eo ≈ 1.2Eop , also the long wavelength refractive index n∞ for the composite was determined from the interception of the vertical axis of figure (6). The values of n∞ were found between 1.27 and 1.06, these values are in good agreement with others [5, 21] . 114 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 The behavior of optical conductivity σop with photon energy is shown in figure (7), it can be seen that, at low Al- concentration 5% and 10%, σop has low values which is due to interface scattering of discontinuous metal particles, Al-particles form small isolated islands embedded in polystyrene matrix, as the Al content increased and reaches a critical point, which represents the moment when there is enough conductive particles present to make a continuous network as the proportion of Al is increased, the islands grow and continuous Al- paths extending through polystyrene are established, the optical conductivity of the composite changing from 0.12×105S.cm-1 for pure polystyrene to 1.32×108S.cm-1 for Ps+30%Al composite, furthermore the σop vary slowly with the volume fraction of aluminum up to 10% and enhanced drastically until 30%, the fluctuation in the optical conductivity at 5% and 10% Al content may be attributed to the segmental mobility of the polymer molecules. Conclusions The effect of additive aluminum on optical properties of polystyrene -aluminum composites has been investigated, we can conclude the following points: 1-The overall absorbance and reflectance have been increased with the increase of Al- content. 2-Conductive was observed in the relationship between band gap energy and composition in the concentration range under study, which was ascribed to the existence of continuous network of aluminum in the polystyrene matrix. 3- Optical band gap of Ps- Al composites decreased with an increase in Al concentration, and the dielectric constant of Ps-Al composites is greater for all filler concentrations and is attributed to interfacial polarization. 4- The optical conductivity of such systems varies continuously as the composition is changed 5- Ps-Al composites are versatile, relatively inexpensive ,useful as light weight shielding for cabinets housing and it is an important material for the modulation of visible light . References 1- Saq’an, S. A.; Ayesh, A. S.; Zihlif, A. and Ragosta, G.(2004) Physical Properties of Polystyrene /Aluminum Composites, Polymer Testing,23(7):739. 2- Suzhu, Yu.; Peter Hing, and Chayahara , A.(2000) Dielectric Properties of Polystyrene - Aluminum-Nitride Composites, J. of Appl .Phys. , 88(1):398. 3 – McCrum ,N.G.C. and Bucknall, B.(1997) Principles of Polymer Engineering ,Second Edition,NewYork,p.242. 4- Alwan, T. J.(2010) Refractive Index Dispersion and Optical Properties of Dye Doped Polystyrene Films, Malaysian Poly. J. 5( 2):204 . 5 – Omed, Gh. A. and Mahmoud, D. S.(2010)Physical Properties of Pure and Copper Oxide Doped Polystyrene Films, International Journal of Material Science,5(4):537. 6- Bahaa, H. & Ahmed, H.(2011) Synthesis and Characterization of Carbon Nanotubes -Polystyrene Composites ,European J. of Scientific Research,60 (2 ):229 7- McQuade, D. T.; Pullen A. E.and Swager, T. M.(2000) Conjugated Polymer-based ChemicalSensors.Chem.Rev.,100(7):253. 8- Liang, G.D. (2008) Electrical properties of percolative polystyrene –carbon nanofibir composites ,Dielectrics and electrical Insulation, IEEE Transaction,15,214. 9-Lucas, G.and Pedroni (2009) Conductivity and Mechanical Properties of Composites Based on MWCNTs and Styrene-Butadiene-Styrene Block TM Copolymers , J. of Applied Polymer Science, 112, 3241 10- Abdul Zahra., S. (2011) Study of the resistivity of the polystyrene-Aluminum composites, j. College of Basic Education ,17(68):89 115 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 11- Pankov, J.I.(1971), Optical Processes in Semiconductors ,Prentice – Hall ,Englewood ,Cliffs,NJ. 12- Lee, P.A.; Said, G., Davis, R.and Lim, T.H.(1969) On the Optical Properties of Some Layer Compounds. J. of the Phys. and Chem. Of solids,30(12):2719 . 13- Tauc, J.; Grigorovici, R. and Vancu, A.(1966) Optical Properties and Electronic Structure of Amorphous Germanium, Physica Status Solidi, 15(2):627. 14- Urbach.F.(1966) Optical Processes , Phys.Rev.92, 627. 15-Mott, N. & Davis, E.,(1979) Electronic Process in Non- Crystalline Materials,2nd Edition, University Press ,Oxford. 16- Hasan, M.; EI Ghanemi, Subhi, A., and Saq’an S. (2011) On the electrical & optical properties of polycarbonate/MnCl composite, J. of Modern. Phys.2,1553. 17-Eloy,J.F. (1984) Power Laser ,National School of Phys., Grenobel ,France ,John Wiley, p.59. 18- Srivastava, S. and Mehra, R. M.,(2009) Study of electrical properties of polystyrene / foliated graphite composite, J. Materials Sci.Poland, 27( 1):529. 19-Yakuphan Oglu, F.and Sekerci, M.(2005) Optical characterization of an amorphous organic thin film,Optica Applicata,35(2):209. 20- Didomenico, M., and Wemple, S.H. (1969) Theory of Electro-Optical and Nonlinear Optical Effects. J. of Appl. Phys. 40(2):720 . 21- Srivastava, S.; Mharidas,M. and Jkbasu,K.( 2008) Optical properties of polymer nanocomposites, Bull. Mater. Sci. 31 (3) :213, Indian Academy of Science. Table No.(1): Gives the values of some optical constants for Ps-Al composites sample ∆E eV δ μm Refractiv e index(n) Extinction coefficient k×10-5 Eo eV Ed eV Pure Ps 0.491 225.4 1.81 5.8 4.84 0.72 Ps+5%Al 0.487 201.8 2 6.3 4.64 0.59 Ps+10%Al 0.473 198.7 3.23 6.9 4.52 0.5 Ps-20%Al 0.453 128.6 4.39 7.4 4.12 0.49 Ps+30%Al 0.422 110.7 6.42 9.34 3.61 0.32 116 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 Figure No.(1): The variation of (A) Absorbance (B) Reflectance with the wavelength for Ps-Al composites. . Figure No. (2): The relation between lnα and photon energy. 0 0.2 0.4 0.6 0.8 1 200 400 600 800 1000 1200 A bs or ba nc e wavelenght nm pure Ps Ps+5%Al Ps+10%Al Ps+20%Al Ps+30%Al A 0 0.2 0.4 0.6 0.8 200 400 600 800 1000 1200 Re fle ct an ce wavelength nm purePs Ps+5%Al Ps+10%Al Ps+20%Al Ps+30%Al B 0 2 4 6 8 10 12 14 16 18 1 1.5 2 2.5 3 3.5 4 4.5 ln α /c m hʋ eV pure PS Ps+5%Al Ps+10%Al Ps+20%Al Ps=30%Al 117 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 Figure No. (3): Variation of (αhυ) 2 versus photon energy for Ps-Al composites. Figure No. (4): The dependence of the optical energy gap on the Al- concentration. 0 100 200 300 400 500 600 700 800 900 1 1.5 2 2.5 3 3.5 4 4.5 5 (α hʋ ) 2 × 10 6 ( ev ) 2 hʋ eV purePs Ps+5%Al Ps+10%Al Ps+20%Al Ps+30%Al 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 0 5 10 15 20 25 30 35 E op e V Al-Concentration % 118 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 Figure No. (5): Real & imaginary part of dielectric constant ( A & B) respectively against photon energy. Figure No. ( 6): The variation of (1/n2-1) with (hυ)2 of pure and doped Polystyrene film. 0 10 20 30 40 50 1 1.5 2 2.5 3 3.5 4 4.5 εr hʋ eV purePs Ps+5%Al Ps+10%Al Ps+30%Al Ps+20%Al 0 5 10 15 20 25 30 35 40 1 1.5 2 2.5 3 3.5 4 4.5 5 ε i m × 1 0- 4 hʋ eV purePs Ps+5%Al Ps+10%Al Ps+20%Al Ps+30%Al 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0 5 10 15 20 1 /n 2 - 1 (hʋ) 2 (eV) 2 purePs Ps+5%Al Ps+10%Al Ps+20%Al Ps=30%Al A B 119 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 Figure No (7): Optical conductivity as a function of photon energy for pure polystyrene & Ps-Al composites 1.0E+00 1.0E+02 1.0E+04 1.0E+06 1.0E+08 1.0E+10 1 1.5 2 2.5 3 3.5 4 4.5 5 σ op S .c m -1 hʋ eV pure Ps Ps+5%Al Ps+10%Al Ps+20%Al Ps+30%Al 120 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013 ألمنیوم-االلمنیوم على الخواص البصریة لمركبات بولي ستایرینضافة إتأثیر سوسن عبد الزھرة قسم العلوم/ كلیة التربیة األساسیة/الجامعة المستنصریة 2012كانون االول 9قبل البحث في : ، 2012ایلول 9استلم البحث في : الخالصة ألمنی�وم بطریق�ة الك�بس المیك�انیكي -أُضیف مسحوق األلمنیوم إلى البولي ستایرین لتحض�یر مرك�ب ب�ولي س�تایرین . ٲجری����ت قیاس����ات االمتصاص����یة واالنعكاس����یة باس����تعمال المطی����اف 120ºCعن����د ض����غط م����نخفض ودرج����ة ح����رارة . Spectrophotometer UV- Visibleالضوئي ، nوعل��ى الثواب��ت البص��ریة (معام��ل االنكس��ار Eopاس��ة ت��أثیر إض��افة األلمنی��وم ف��ي فج��وة الطاق��ة البص��ریة تم��ت در ) للمركبات المحضرة.σop، والتوصیلیة البصریة ε، وثابت العزلkوعامل الخمود مع زیادة نسبة األلمنیوم في المركب إذ انخفضت قیمتھا من Eopأظھرت النتائج انخفاض قیمة فجوة الطاقة البصریة 4.1eV 3.12للبولي ستایرین النقي إلى حواليeV للمركبPs+30%Al) وتبین أن قیم كل من ،( nوk تتغیر تغیرا ملحوظا وھذا التغیر مصاحب للزیادة في التشتت، االنعكاسیة واالمتصاص البصري لسطح األغشیة مع زیادة نسبة عالیة لجمیع نسب األلمنیوم وھذا قد یعود إلى االستقطاب البیني في األوساط المختلطة εمنیوم وكانت قیم ثابت العزل األل heterogeneous105×0.12. ولوحظ ان قیم التوصیلیة البصریة قد ازدادت منS.cm-1 للبولي ستایرین النقي إلى حوالي 1.32×108S.cm-1 للمركب Ps+30%Al . ألمنیوم باختیار الكمیة –ان ھذه النتائج تدل على انھ یمكن التحكم في الخواص البصریة لمركب بولي ستایرین الصحیحة من الشوائب، ویمكن تغییر الثوابت البصریة بإضافة كمیة محددة من الشوائب وبھذا یمكن زیادة التطبیقات الصناعیة لھذه المركبات. ولي ستایرین، مركبات البولي ستایرین، الخواص البصریة.: بالكلمات المفتاحیة 121 | Physics @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹1a26@@ÖÜ»€a@I3@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (3) 2013