Chemistry - 213 مجلة إبن الهيثم للعلوم الصرفة و التطبيقية 2012 السنة 25 المجلد 3 العدد Ibn Al-Haitham Journal for Pure and Applied Science No. 3 Vol. 25 Year 2012 Effect of Temperature On The Dispersability Of The Grafted Acrylic Acid Onto Alumina Particles M. T. Sultan, A. H. Al-Dujiali *H. S. Al-Lami Department of Chemistry, College of Education Ibn-AlHaitham, University of Baghdad *Department of Chemistry, College of Science, University of Basrah Received in :22Februrary 2011 Accepted in :18 March 2012 Abstract The ability of different alumina-grafted particles was examined for adsorption of phenol and p-chlorophenol under different conditions (i.e. concentrations and temperatures). Dispersion stability of alumina in liquid medium (water) was studied using settling under gravity technique. The result shows the settling initial rate of the alumina-grafted acrylic acid particles was faster than initial rate of settling when alumina-graft acrylic acid monomer adsorbed phenol and p-chlorophenol and vice versa to the alumina-graft poly(acrylic acid) polymer. Thermodynamic parameters values (∆G, ∆S, ∆H) were calculated for adsorption processes of phenol and p-chlorophenol adsorbed onto different surfaces. The results revealed that positive and negative values were obtained implying that both endothermic and exothermic adsorption reactions may took place. Key Words:Polymers,Polymers Adsorption,graft Alumina Introduction Adsorption of small molecules or polymeric materials onto solid surface plays an important role in a large number of practical applications, and provides good information about the physical and chemical properties of polymer in solution through their interaction with solid surface [1]. There are various factors that influence the adsorption process, such as chemical structure of the adsorbate, the nature of adsorbent, the solvent from which adsorption is made, and the type of anchoring groups [2]. In general when the concentration of adsorbate increases the capacity of adsorption increases [3]. In some cases, adsorption may be confined to only one layer of adsorbed molecules, i.e., only one molecule deep. Further adsorption ceases when the surface of the crystal lattice of adsorbent is covered [4]. The diagram representing the relationship between quantity adsorbed and the equilibrium concentration is called adsorption isotherm [5]. In physical adsorption, a decrease in temperature enhances the extent of adsorption. The decrease of adsorption with the increase of temperature implies by lechatelier's principle, that heat is evolved in the process of adsorption [6]. In chemisorptions, the quantity adsorbed may increase or decrease with rising temperature depending on the type of interaction and the bonding between the surface and the adsorbed molecules [7]. In most cases, chemisorptions require energy of activation. The amount of this energy is a function of type and the nature of adsorbate-adsorbent interaction and the concentration of adsorbate solution [8]. Natural water pollution by organic materials, such phenol and its derivatives which are the most harmful contamination, increases due to industrial activities and accidents. In previous work, free radical polymerization was carried out onto alumina surface grafted with acrylic monomer. The later was chain extended by additional acrylic acid monomer in the presence of Chemistry - 214 مجلة إبن الهيثم للعلوم الصرفة و التطبيقية 2012 السنة 25 المجلد 3 العدد Ibn Al-Haitham Journal for Pure and Applied Science No. 3 Vol. 25 Year 2012 benzoyl peroxide as initiator. The grafted monomer and polymer was characterized by different spectroscopic techniques, and was thermally analyzed [9]. In this paper,we studied the adsorption behavior to the standard alumina and to the compounds alumina-graft acrylic acid monomer and alumina-graft poly(acrylic acid)that we prepared at different temperatures and calculate thermodynamic parameters of the surface. Experimental Materials Alumina,Alumina-grafted with acrylic acid monomer and Alumina-grafted poly(acrylic acid) polymer prepared and characterized as mentioned elsewhere[9]. Determination of maximum adsorption (λmax) Ultra violet scanning spectrum of phenol and p-chlorophenol are recorded practically within the range (200-400) nm using (10 mm) width quartz . Wavelength values (λmax) corresponding to the maximum absorbance for phenol and p-chlorophenol were (270nm) (280nm), respectively. Many solutions of different concentrations were prepared by serial solutions of phenol and p- chlorophenol. Absorbance values of these solutions were measured at specific (λmax) values for phenol and p-chlorophenol. In order to obtain the calibration curves of the (phenol and p-chlorophenol) solutions, the absorbency values plotted versus the concentration for both of them . The concentration range that falls in the region of applicability of Beer-Lambert's law was estimated and then used for subsequent determinations. The amount of adsorbed phenol and p- chlorophenol was calculated from the initial and final concentration and the volume of solution. by the equation:- m )CV(C eo −=Qe ………. (1) Where: Qe :quantity of adsorbate V: volume of solution (ml). Co: initial concentration (mg/ml). Ce: equilibrium concentration (mg/ml). Adsorption uptake is expressed by the ratio (x/m) {also called Qe which is defined as the quantity of adsorbate in (mg) held by (0.2) g of adsorbent} at certain conditions (temperature, pH). (Qe) values were plotted versus the equilibrium concentrations (Ce); the resulting diagrams are the adsorption isotherms that required for understanding and interpreting the systems under investigation [9]. Results and discussion Studying the effect of temperatures on adsorption of phenol and p-chlorophenol were examined on the surfaces under study { standard alumina, alumina-graft acrylic acid monomer, and alumina-graft poly(acrylic acid)} at four temperatures (10, 25, 40, and 55) ºC .The results are listed in tables (1), (2) and (3)which, show the experimental data for all adsorbent surface As shown form these tables, adsorption of phenol increased on the surfaces of alumina-grafted acrylic acid monomer and alumina-grafted poly (acrylic acid), when the temperature increased, while the adsorption of phenol decreased on the surfaces of standard alumina when temperature increased. On the other hand adsorption of p-chlorophenol on the surfaces was increased for standard alumina and alumina-graft poly (acrylic acid) as the temperature increased, and the adsorption decreased only on the surface of alumina-graft acrylic acid monomer when temperature increased. Increasing the adsorption with increase temperature indicates that the adsorption is endothermic process; the molecules get a place on the crystal net work of the surface, and diffusion speed increase when temperature increases. These results include absorption and adsorption processes together and the dominant process is adsorption [10, 11]. Chemistry - 215 مجلة إبن الهيثم للعلوم الصرفة و التطبيقية 2012 السنة 25 المجلد 3 العدد Ibn Al-Haitham Journal for Pure and Applied Science No. 3 Vol. 25 Year 2012 The decrease in adsorption with the increase of temperature, the process is considered as an exothermic process, and that will be agreed with thermodynamic properties for adsorption [12]. Thermodynamic parameters The enthalpy (∆H) of adsorption of phenol and p-chlorophenol were calculated using the known thermodynamic equations [9]. The results are shown in table (4). Examining table (4) reveals quite clearly that the adsorption of phenol and p-chlorophenol on the surfaces of the materials under studying having both types of endothermic and exothermic processes. The values of enthalpy (∆H) of the phenol adsorption onto alumina particles surface, alumina- grafted acrylic acid monomer and alumina-grafted poly(acrylic acid) are negative. This implies that the adsorption process is exothermic, whereas positive values were obtained for (∆H) indicating an endothermic type of adsorption for phenol onto alumina-grafted poly (acrylic acid). The values of (∆G) for all surfaces are positive this indicates that the adsorption process is non-spontaneous. Values of (∆S) are negative and positive for surfaces adsorbate phenol and p- chlorophenol. The negative value gives proof that the adsorbate molecules may arrange themselves on the surface as consequence of binding, so that adsorbate molecules will be more regulate than in solution. But the positive value of (∆S) means that adsorbate molecules are less regulate than in solution when absorption and adsorption processes are together [13]. The (∆H) values of p-chlorophenol for standard alumina and alumina-grafted poly(acrylic acid) surfaces are positive and to the alumina-graft acrylic acid monomer is negative, but (∆G) values for all surfaces are positive implies that adsorption process proceeds non-spontaneous. (∆S) Values to standard alumina, alumina-graft acrylic acid monomer, and to alumina-graft poly(acrylic acid) are negative. The above results lead to concede that the phenol molecules as adsorbate have better conformation onto different adsorbent surfaces comparing to the other adsorbed molecules, i.e. p-chlorophenol, this may explained in term of the size and polarity of the later adsorbate molecules. References 1. Sequaris, J.M.; Hild, A.; Narres, H.D. and Schwuger, M.J. (2000)”polyvinyl prrolidone adsorption on Na-montmorillonite.Effect of the polymer interfacial conformation on the colloidal behavior and binding of chemicals”,J.Coll.Interf.Sci. 230:73-83. 2.Mekhamer,M.T. (2006)”characterization of clay minerals with some polymeric materials”, J.Saudi.Chem.Soc. 10 (2): 239-252 3.Uddin, M.T. ;Islam, M.S. and Abedin ,M.Z. (2007)”adsorption of phenol from aqueous solution by water Hyacinth ASH”, ARPN Journal of engineering and applied sciences, 2(2): 11-17. 4. Pekel, N. and Güven, O. (2002)”solvent,temperature and concentration effeets on the adsorption of poly(n-Butyl methacrylate)on alumina from solutions”, Turk J. Chem, 26: 221- 228 5. Adamson, A. ( 1984) “Physical Chemistry of Surfaces”, 4th (Ed.), Wiley Interscience Publishers, 369. 6. Glasstone, S. (1962) “Physical Chemistry” 2nd (Ed.), Wiley Publishers, 1194-1219 7. Cooney, D.O. ( 1999) “Adsorption Design for Water Treatment”, Lewis Publishers, CRC Press, Boca Raton. 8.Mmane ,S.M.; Vanjara ,A.K. and Sawant, M.R. (2005)”removal of phenol from waste water using date seed carbon”, Journal of the Chinese chemical society, 52:1117-1122. 9. Sultan, M.T. (2007) " Chemical and thermal study of alumina grafted with acrylic acid monomer and it's polymeric liquid crystalline derivatives". Ph.D. Thesis, College of Education/Ibn- Al-Haitham, University of Baghdad, Baghdad. 10.Cardenas, S.A. and Perea, B.G. (2005)”Adsorption of phenol and dichlorophenol from aquesous solution by porous clay hetrostracture (PCH)”, J.Mex.chem.Soc,49(3):287-291 Chemistry - 216 مجلة إبن الهيثم للعلوم الصرفة و التطبيقية 2012 السنة 25 المجلد 3 العدد Ibn Al-Haitham Journal for Pure and Applied Science No. 3 Vol. 25 Year 2012 11.Qadeer R. and Rehan A.H. (2002)”Astudy of the adsorption of phenol by activated carbon from aqueous solutions”, Turk J.chem, 26:357-361 12.Singleton, N.L.; Huddersman, K.D. and Neetham ,M.I. (1998)”the adsorption properties of Nay zeolite for separation of aromatic triazoles”, J.chem.Soc.Faraday Trans, 94:3777-3780. 13.Fabing, F.; Hui, T.M. and Zhao, X.S. (2005)”phenol adsorption on zeolite_templated carbons with different structural and surface properties” J. Carbon, 43: 1156-1164. Table (1): The effect of temperature on adsorption of phenol and p-chlorophenol on Alumina surface p-Clorophenol 10 ºC 25 ºC 40 ºC 55 ºC Co (mg/L) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) 100 75.74 1.213 92.63 0.368 91.20 0.440 89.66 0.517 125 99.37 1.281 117.13 0.393 114.13 0.543 112.34 0.633 150 120.39 1.480 136.40 0.680 133.74 0.813 134.31 0.784 175 105.51 3.474 148.27 1.336 127.54 2.373 124.00 2.550 200 126.58 3.671 172.87 1.356 144.54 2.773 136.43 3.178 225 138.74 4,313 192.16 1.642 150.47 3.726 146.76 3.912 250 153.02 4.849 213.16 1.842 182.74 3.363 172.98 3.851 Phenol 10 ºC 25 ºC 40 ºC 55 ºC Co (mg/L) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) 100 86.07 0.696 86.12 0.694 89.09 0.545 88.37 0.581 125 106.77 0.911 106.81 0.909 109.92 0.754 108.86 0.807 150 123,07 1,346 122,56 1,372 128,61 1,069 125,15 1,242 175 152.91 1.104 152.90 1.105 150.84 1.208 156.30 0.935 200 184.20 0.790 182.99 0.850 168.71 1.564 175.09 1.245 225 184.66 2.017 188.41 1.829 200.88 1.206 194.16 1.542 250 210.42 1.979 221.90 1.405 221.93 1.403 228.47 1.076 Chemistry - 217 مجلة إبن الهيثم للعلوم الصرفة و التطبيقية 2012 السنة 25 المجلد 3 العدد Ibn Al-Haitham Journal for Pure and Applied Science No. 3 Vol. 25 Year 2012 Table (2): The effect of temperature on adsorption of phenol and p-chlorophenol on alumina- graft acrylic acid monomer surface Phenol 10 ºC 25 ºC 40 ºC 55 ºC Co (mg/L) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Q e(mg/g) 100 82.79 0.860 87.11 0.644 88.40 0.580 88.45 0.577 125 102.34 1.133 104.90 1.005 114.42 0.529 107.07 0.896 150 118.26 1.587 124.35 1.282 112.17 1.391 122.32 1.384 175 131.74 2.163 132.62 2.119 127.73 2.363 139.13 1.793 200 72.03 6.398 148.34 2.583 173.98 1.301 173.13 1.343 225 83.43 7.078 184.99 2.000 183.54 2.073 174.32 2.534 250 102.28 7.386 204.08 2.295 202.01 2.399 187.14 3.143 p-Clorophenol 10 ºC 25 ºC 40 ºC 55 ºC Co (mg/L) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) 100 84.27 0.786 78.93 1.053 88.59 0.570 88.33 0.583 125 102.20 1.138 100.52 1.224 107.16 0.892 110.89 0.705 150 123.08 1.346 121.69 1.415 132.40 0.880 134.06 0.797 175 136.51 1.924 113.82 3.059 132.34 2.133 148.87 1.306 200 141.14 2.943 137.94 3.103 162.23 1.888 171.49 1.425 225 149.71 3.764 154.34 3.533 166.98 2.901 198.89 1.305 250 176.23 3.688 180.36 3.481 195.45 2.727 199.65 2.517 Table (3): The effect of temperature on adsorption of phenol and p-chlorophenol on polymer (A) surface Phenol 10 ºC 25 ºC 40 ºC 55 ºC Co (mg/L) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) 100 94.90 0.255 79.50 1.025 78.94 1.053 72.98 1.351 125 118.14 0.343 102.93 1.103 104.02 1.049 97.60 1.370 150 127.91 1.104 115.21 1.739 117.32 1.634 110.90 1.955 175 130.34 2.233 120.49 2.725 129.29 2.285 111.29 3.185 200 173.70 1.315 166.56 1.672 156.22 2.189 149.98 2.501 225 178.38 2.331 200.20 1.240 186.34 1.933 171.06 2.697 250 209.17 2.041 202.72 2.364 202.42 2.379 191.77 2.911 Chemistry - 218 مجلة إبن الهيثم للعلوم الصرفة و التطبيقية 2012 السنة 25 المجلد 3 العدد Ibn Al-Haitham Journal for Pure and Applied Science No. 3 Vol. 25 Year 2012 p-Clorophenol 10 ºC 25 ºC 40 ºC 55 ºC Co (mg/L) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) Ce (mg/L) Qe (mg/g) 100 80.56 0.972 82.00 0.900 84.21 0.789 77.30 1.135 125 95.22 1.489 98.49 1.325 102.08 1.146 101.82 1.159 150 114.00 1.800 121.81 1.409 123.61 1.319 118.89 1.555 175 130.16 2.242 127.80 2.360 137.83 1.858 134.75 2.012 200 142.91 2.854 148.13 2.593 150.38 2.481 141.09 2.945 225 178.54 2.323 167.69 2.865 173.45 2.577 152.69 3.615 250 205.45 2.227 188.73 3.063 183.65 3.317 174.23 3.788 Table (4): Thermodynamic data to adsorption phenol and p-chlorophenol at the surfaces under study at 25 ºC Surfaces Phenol p-Clorophenol ∆H (KJ/mol) ∆G (KJ/mol) ∆S (J/mol.K) ∆H (KJ/mol) ∆G (KJ/mol) ∆S (J/mol.K) Standard Alumina -6.466 11.982 -0.062 28.268 11.642 0.056 Alumina-grafted acrylic acid monomer -78.512 11.345 -0.301 -15.872 9.819 0.020 Alumina-grafted poly(acrylic acid) 10.392 12.470 0.003 9.238 10.105 -0.003 Fig. (2): Scanning spectrum of p-chlorophenol Fig.(1):Scanning spectrum of phenol Chemistry - 219 مجلة إبن الهيثم للعلوم الصرفة و التطبيقية 2012 السنة 25 المجلد 3 العدد Ibn Al-Haitham Journal for Pure and Applied Science No. 3 Vol. 25 Year 2012 تأثيرالتغيير في درجات الحرارة على انتشارية حامض االكريلك المطعم بين جزيئات االلومينا هادي عباس الالمي * ،عمار هاني الدجيلي ،مها طاهر سلطان قسم الكيمياء ، ابن الهيثم ،جامعة بغداد-كلية التربية قسم الكيمياء، كلية العلوم، جامعة البصرة * 2012آذار 18قبل البحث في: ، 2011شباط 22استلم البحث في : الخالصة تم في هذه الدراسة اختبار قابلية سطوح جسيمات األلومينا ، األلومينا المطعمة بمونمر حامض األكريلك و األلومينا ل تحت ظروف مختلفة من درجات الحرارة .كلوروفينو-المطعمة ببولي (حامض األكريلك) ألمتزا ز جزيئات الفينول وبارا كلورو فينول على السطوح قيد الدراسة -لعملية امتزاز الفينول والبارا (H ,∆S ,∆G∆ )تم حساب الدوال الثرموديناميكيةو وأظهرت النتائج قيم موجبة وأخرى سالبة داللة على حدوث عمليات امتزاز محبة للحرارة وأخرى باعثة للحرارة. :البوليمرات،امتزازالبوليمرات،االلومينا المطعمت المفتاحيةالكلما Thermodynamic parameters