Effect of hyamine on electrochemical behaviour of brass alloy in HNO3 solution
-
Demet Özkır
,
Emel Bayol
Abstract
The electrochemical behaviours of a brass alloy in 0.1 M nitric acid, including the hyamine inhibitor with concentrations between 2.5 × 10−4 M and 1.0 × 10−5 M, were studied. For this purpose, potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS), linear polarisation resistance (LPR) techniques, and flame atomic absorption spectroscopy (FAAS) were utilised. The inhibitor molecules adsorbed on the brass surface were calculated to be in good agreement with the Langmuir adsorption isotherm and the standard free enthalpy of adsorption (ΔG ads∘). Hyamine effectively improved the corrosion inhibition of brass and acted as a mixed-type inhibitor on alloy surfaces. The surface morphology of the alloy was also clarified by optical microscopic and SEM techniques. A theoretical study of the corrosion inhibition efficiency of hyamine molecule was carried out using density functional theory (DFT) at the B3LYP/6-311G(d,p) basis set level.
[1] Abboud, Y., Abourriche, A., Saffaj, T., Berrada, M., Charrouf, M., Bennamara, A., & Hannache, H. (2009). A novel azo dye, 8-quinolinol-5-azoantipyrine as corrosion inhibitor for mild steel in acidic media. Desalination, 237, 175–189. DOI:10.1016/j.desal.2007.12.031. http://dx.doi.org/10.1016/j.desal.2007.12.03110.1016/j.desal.2007.12.031Search in Google Scholar
[2] Abdallah, M., Al-Agez, M., & Fouda, A. S. (2009). Phenylhydrazone derivatives as corrosion inhibitors for -α-brass in hydrochloric acid solutions. International Journal of Electrochemical Science, 4, 336–352. Search in Google Scholar
[3] Abd El Meguid, E. A., & Awad, N. K. (2009). Electrochemical pitting corrosion behaviour of α-brass in LiBr containing solutions. Corrosion Science, 51, 1134–1139. DOI: 10.1016/j.corsci.2009.02.019. http://dx.doi.org/10.1016/j.corsci.2009.02.01910.1016/j.corsci.2009.02.019Search in Google Scholar
[4] Abed, Y., Kissi, M., Hammouti, B., Taleb, M., & Kertit, S. (2004). Peptidic compound as corrosion inhibitor for brass in nitric acid solution. Progress in Organic Coatings, 50, 144–147. DOI:10.1016/j.porgcoat.2004.02.001. http://dx.doi.org/10.1016/j.porgcoat.2004.02.00110.1016/j.porgcoat.2004.02.001Search in Google Scholar
[5] Ahamad, I., Prasad, R., & Quraishi, M. A. (2010). Adsorption and inhibitive properties of some new Mannich bases of Isatin derivatives on corrosion of mild steel in acidic media. Corrosion Science, 52, 1472–1481. DOI:10.1016/j.corsci.2010.01.015. http://dx.doi.org/10.1016/j.corsci.2010.01.01510.1016/j.corsci.2010.01.015Search in Google Scholar
[6] Alfantazi, A. M., Ahmed, T. M., & Tromans, D. (2009). Corrosion behavior of copper alloys in chloride media. Materials & Design, 30, 2425–2430. DOI:10.1016/j.matdes.2008.10.015. http://dx.doi.org/10.1016/j.matdes.2008.10.01510.1016/j.matdes.2008.10.015Search in Google Scholar
[7] Aljourani, J., Raeissi, K., & Golozar, M. A. (2009). Benzimidazole and its derivatives as corrosion inhibitors for mild steel in 1M HCl solution. Corrosion Science, 51, 1836–1843. DOI:10.1016/j.corsci.2009.05.011. http://dx.doi.org/10.1016/j.corsci.2009.05.01110.1016/j.corsci.2009.05.011Search in Google Scholar
[8] Aljourani, J., Golozar, M. A., & Raeissi, K. (2010). The inhibition of carbon steel corrosion in hydrochloric and sulfuric acid media using some benzimidazole derivatives. Materials Chemistry and Physics, 121, 320–325. DOI: 10.1016/j.matchemphys.2010.01.040. http://dx.doi.org/10.1016/j.matchemphys.2010.01.04010.1016/j.matchemphys.2010.01.040Search in Google Scholar
[9] Allam, N. K. (2007). Thermodynamic and quantum chemistry characterization of the adsorption of triazole derivatives during Muntz corrosion in acidic and neutral solutions. Applied Surface Science, 253, 4570–4577. DOI:10.1016/j.apsusc.2006.10.008. http://dx.doi.org/10.1016/j.apsusc.2006.10.00810.1016/j.apsusc.2006.10.008Search in Google Scholar
[10] Asefi, D., Arami, M., & Mahmoodi, N. M. (2010). Electrochemical effect of cationic gemini surfactant and halide salts on corrosion inhibition of low carbon steel in acid medium. Corrosion Science, 52, 794–800. DOI:10.1016/j.corsci.2009.10.039. http://dx.doi.org/10.1016/j.corsci.2009.10.03910.1016/j.corsci.2009.10.039Search in Google Scholar
[11] Bayol, E., Kayakırılmaz, K., & Erbil, M. (2007). The inhibitive effect of hexamethylenetetramine on the acid corrosion of steel. Materials Chemistry and Physics, 104, 74–82. DOI:10.1016/j.matchemphys.2007.02.073. http://dx.doi.org/10.1016/j.matchemphys.2007.02.07310.1016/j.matchemphys.2007.02.073Search in Google Scholar
[12] Bayol, E., Gürten, T., Gürten, A. A., & Erbil, M. (2008). Interactions of some Schiff base compounds with mild steel surface in hydrochloric acid solution. Materials Chemistry and Physics, 112, 624–630. DOI:10.1016/j.matchemphys.2008.06.012. http://dx.doi.org/10.1016/j.matchemphys.2008.06.01210.1016/j.matchemphys.2008.06.012Search in Google Scholar
[13] Becke, A. D. (1993). Density-functional thermochemistry. III. The role of exact exchange. The Journal of Chemical Physics, 98, 5648–5652. DOI: 10.1063/1.464913. http://dx.doi.org/10.1063/1.46491310.1063/1.464913Search in Google Scholar
[14] Behpour, M., Ghoreishi, S. M., Soltani, N., & Salavati-Niasari, M. (2009). The inhibitive effect of some bis-N,S-bidentate Schiff bases on corrosion behaviour of 304 stainless steel in hydrochloric acid solution. Corrosion Science, 51, 1073–1082. DOI:10.1016/j.corsci.2009.02.011. http://dx.doi.org/10.1016/j.corsci.2009.02.01110.1016/j.corsci.2009.02.011Search in Google Scholar
[15] Elayyachy, M., Elkodadi, M., Aouniti, A., Ramdani, A., Hammouti, B., Malek, F., & Elidrissi, A. (2005). New bipyrazole derivatives as corrosion inhibitors for steel in hydrochloric acid solutions. Materials Chemistry and Physics, 93, 281–285. DOI:10.1016/j.matchemphys.2005.03.059. http://dx.doi.org/10.1016/j.matchemphys.2005.03.05910.1016/j.matchemphys.2005.03.059Search in Google Scholar
[16] Erbil, M. (1988). The determination of corrosion rates by analysis of AC impedance diagrams. Chimica Acta Turcica, 1, 59–70. Search in Google Scholar
[17] Fontana, M. G., & Greene, N. D. (1967). Corrosion engineering (pp. 270). New York, NY, USA: McGraw-Hill. Search in Google Scholar
[18] Frisch, M. J., Trucks, G. W., Schlegel, H. B., Scuseria, G. E., Robb, M. A., Cheeseman, J. R., Scalmani, G., Barone, V., Mennucci, B., Petersson, G. A., Nakatsuji, H., Caricato, M., Li, X., Hratchian, H. P., Izmaylov, A. F., Bloino, J., Zheng, G., Sonnenberg, J. L., Hada, M., Ehara, M., Toyota, K., Fukuda, R., Hasegawa, J., Ishida, M., Nakajima, T., Honda, Y., Kitao, O., Nakai, H., Vreven, T., Montgomery, J. A., Jr., Peralta, J. E., Ogliaro, F., Bearpark, M., Heyd, J. J., Brothers, E., Kudin, K. N., Staroverov, V. N., Kobayashi, R., Normand, J., Raghavachari, K., Rendell, A., Burant, J. C., Iyengar, S. S., Tomasi, J., Cossi, M., Rega, N., Millam, J. M., Klene, M., Knox, J. E., Cross, J. B., Bakken, V., Adamo, C., Jaramillo, J., Gomperts, R., Stratmann, R. E., Yazyev, O., Austin, A. J., Cammi, R., Pomelli, C., Ochterski, J. W., Martin, R. L., Morokuma, K., Zakrzewski, V. G., Voth, G. A., Salvador, P., Dannenberg, J. J., Dapprich, S., Daniels, A. D., Farkas, Ö., Foresman, J. B., Ortiz, J. V., Cioslowski, J., & Fox, D. J. (2009). Gaussian 09, Revision A.1 [computer software]. Wallingford, CT, USA: Gaussian. Search in Google Scholar
[19] Fuchs-Godec, R. (2006). The adsorption, CMC determination and corrosion inhibition of some N-alkyl quaternary ammonium salts on carbon steel surface in 2 M H2SO4. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 280, 130–139. DOI:10.1016/j.colsurfa.2006.01.046. http://dx.doi.org/10.1016/j.colsurfa.2006.01.04610.1016/j.colsurfa.2006.01.046Search in Google Scholar
[20] Fuchs-Godec, R. (2007). Inhibitory effect of non-ionic surfactants of the TRITON-X series on the corrosion of carbon steel in sulphuric acid. Electrochimica Acta, 52, 4974–4981. DOI:10.1016/j.electacta.2007.01.075. http://dx.doi.org/10.1016/j.electacta.2007.01.07510.1016/j.electacta.2007.01.075Search in Google Scholar
[21] Gao, G., & Liang, C. H. (2007). 1,3-Bis-diethylamino-propan-2-ol as volatile corrosion inhibitor for brass. Corrosion Science, 49, 3479–3493. DOI:10.1016/j.corsci.2007.03.030. http://dx.doi.org/10.1016/j.corsci.2007.03.03010.1016/j.corsci.2007.03.030Search in Google Scholar
[22] Herrag, L., Hammouti, B., Elkadiri, S., Aouniti, A., Jama, C., Vezin, H., & Bentiss, F. (2010). Adsorption properties and inhibition of mild steel corrosion in hydrochloric solution by some newly synthesized diamine derivatives: Experimental and theoretical investigations. Corrosion Science, 52, 3042–3051. DOI:10.1016/j.corsci.2010.05.024. http://dx.doi.org/10.1016/j.corsci.2010.05.02410.1016/j.corsci.2010.05.024Search in Google Scholar
[23] Horton, R. M. (1970). New metallographic evidence for dezincification of brass by redisposition of copper. Corrosion, 26, 160–163. 10.5006/0010-9312-26.6.260Search in Google Scholar
[24] Kılınççeker, G. (2008). The effects of acetate ions on electrochemical behaviour of brass in chloride solutions. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 329, 112–118. DOI:10.1016/j.colsurfa.2008.07.002. http://dx.doi.org/10.1016/j.colsurfa.2008.07.00210.1016/j.colsurfa.2008.07.002Search in Google Scholar
[25] Langenegger, E. E., & Robinson, F. P. A. (1968). Effect of the polarization technique on dezincification rates and the physical structure of dezincified zones. Corrosion-NACE, 24, 411–417. 10.5006/0010-9312-24.12.411Search in Google Scholar
[26] Langenegger, E. E., & Robinson, F. P. A. (1969). A study of the mechanism of dezincification of brasses. Corrosion-NACE, 25, 59–66. 10.5006/0010-9312-25.2.59Search in Google Scholar
[27] Li, X. H., Deng, S. D., Fu, H., & Li, T. H. (2009). Adsorption and inhibition effect of 6-benzylaminopurine on cold rolled steel in 1.0 M HCl. Electrochimica Acta, 54, 4089–4098. DOI:10.1016/j.electacta.2009.02.084. http://dx.doi.org/10.1016/j.electacta.2009.02.08410.1016/j.electacta.2009.02.084Search in Google Scholar
[28] Mahmoud, S. S. (2007). Corrosion inhibition of Cu-Fe alloys in HCl solutions by amphoteric surfactants. Corrosão e Protecção de Materiais, 26, 53–60. Search in Google Scholar
[29] Mihit, M., El Issami, S., Bouklah, M., Bazzi, L., Hammouti, B., Addi, E. A., Salghi, R., & Kertit, S. (2006). The inhibited effect of some tetrazolic compounds towards the corrosion of brass in nitric acid solution. Applied Surface Science, 252, 2389–2395. DOI:10.1016/j.apsusc.2005.04.009. http://dx.doi.org/10.1016/j.apsusc.2005.04.00910.1016/j.apsusc.2005.04.009Search in Google Scholar
[30] Milošev, I., Mikić, T. K., & Gaberšček, M. (2006). The effect of Cu-rich sub-layer on the increased corrosion resistance of Cu-xZn alloys in chloride containing borate buffer. Electrochimica Acta, 52, 415–426. DOI:10.1016/j.electacta.2006.05.024. http://dx.doi.org/10.1016/j.electacta.2006.05.02410.1016/j.electacta.2006.05.024Search in Google Scholar
[31] Obot, I. B., Obi-Egbedi, N. O., & Umoren, S. A. (2009). The synergistic inhibitive effect and some quantum chemical parameters of 2,3-diaminonaphthalene and iodide ions on the hydrochloric acid corrosion of aluminium. Corrosion Science, 51, 276–282. DOI:10.1016/j.corsci.2008.11.013. http://dx.doi.org/10.1016/j.corsci.2008.11.01310.1016/j.corsci.2008.11.013Search in Google Scholar
[32] Özkır, D., & Bayol, E. (2011). Inhibition efficiency of benzidine for mild steel in acidic media. Protection of Metals and Physical Chemistry of Surfaces, 47, 517–527. DOI:10.1134/s2070205111040150. http://dx.doi.org/10.1134/S207020511104015010.1134/S2070205111040150Search in Google Scholar
[33] Özkır, D., Kayakırılmaz, K., Bayol, E., Gürten, A. A., & Kandemirli, F. (2012). The inhibition effect of Azure A on mild steel in 1 M HCl. A complete study: Adsorption, temperature, duration and quantum chemical aspects. Corrosion Science, 56, 143–152. DOI:10.1016/j.corsci.2011.11.010. http://dx.doi.org/10.1016/j.corsci.2011.11.01010.1016/j.corsci.2011.11.010Search in Google Scholar
[34] Pchelnikov, A. P., Sitnikov, A. D., Marshakov, I. K., & Losev, V. V. (1981). A study of the kinetics and mechanism of brass dezincification by radiotracer and electrochemical methods. Electrochimica Acta, 26, 591–600. DOI: 10.1016/0013-4686(81)80025-4. http://dx.doi.org/10.1016/0013-4686(81)80025-410.1016/0013-4686(81)80025-4Search in Google Scholar
[35] Pickering, H.W. (1970). Formation of new phases during anodic dissolution of Zn-rich Cu-Zn alloys. Journal of the Electrochemical Society, 117, 8–15. DOI: 10.1149/1.2407450. http://dx.doi.org/10.1149/1.240745010.1149/1.2407450Search in Google Scholar
[36] Pickering, H. W., & Wagner, C. (1967). Electrolytic dissolution of binary alloy containing a noble metal. Journal of the Electrochemical Society, 114, 698–706. DOI: 10.1149/1.2426709. http://dx.doi.org/10.1149/1.242670910.1149/1.2426709Search in Google Scholar
[37] Pickering, H. W., & Byrne, P. J. (1971). On preferential anodic dissolution of alloys in the low-current region and the nature of the critical potential. Journal of the Electrochemical Society, 118, 209–215. DOI: 10.1149/1.2407969. http://dx.doi.org/10.1149/1.240796910.1149/1.2407969Search in Google Scholar
[38] Polunin, A. V., Pchelnikov, A. P., Losev, V. V., & Marshakov, I. K. (1982). Electrochemical studies of the kinetics and mechanism of brass dezincification. Electrochimica Acta, 27, 467–475. DOI: 10.1016/0013-4686(82)85025-1. http://dx.doi.org/10.1016/0013-4686(82)85025-110.1016/0013-4686(82)85025-1Search in Google Scholar
[39] Ramji, K., Cairns, D. R., & Rajeswari, S. (2008). Synergistic inhibition effect of 2-mercaptobenzothiazole and Tween-80 on the corrosion of brass in NaCl solution. Applied Surface Science, 254, 4483–4493. DOI:10.1016/j.apsusc.2008.01.031. http://dx.doi.org/10.1016/j.apsusc.2008.01.03110.1016/j.apsusc.2008.01.031Search in Google Scholar
[40] Ranjana, Maji, M., & Nandi, M. M. (2009). Corrosion inhibition of brass in presence of sulphonamidoimidazoline and hydropyrimidine in chloride solution. Indian Journal of Chemical Technology, 16, 221–227. Search in Google Scholar
[41] Ravichandran, R., & Rajendran, N. (2005a). Influence of benzotriazole derivatives on the dezincification of 65-35 brass in sodium chloride. Applied Surface Science, 239, 182–192. DOI:10.1016/j.apsusc.2004.05.145. http://dx.doi.org/10.1016/j.apsusc.2004.05.14510.1016/j.apsusc.2004.05.145Search in Google Scholar
[42] Ravichandran, R., & Rajendran, N. (2005b). Electrochemical behaviour of brass in artificial seawater: effect of organic inhibitors. Applied Surface Science, 241, 449–458. DOI:10.1016/j.apsusc.2004.07.046. http://dx.doi.org/10.1016/j.apsusc.2004.07.04610.1016/j.apsusc.2004.07.046Search in Google Scholar
[43] Robinson, F. P. A., & Shalit, M. (1964). The dezincification of brass. Anti-Corrosion Methods and Materials, 11(4), 11–14. DOI:10.1108/eb020168. http://dx.doi.org/10.1108/eb02016810.1108/eb020168Search in Google Scholar
[44] Solmaz, R., Karda, G., Çulha, M., Yazıcı, B., & Erbil, M. (2008a). Investigation of adsorption and inhibitive effect of 2-mercaptothiazoline on corrosion of mild steel in hydrochloric acid media. Electrochimica Acta, 53, 5941–5952. DOI:10.1016/j.electacta.2008.03.055. http://dx.doi.org/10.1016/j.electacta.2008.03.05510.1016/j.electacta.2008.03.055Search in Google Scholar
[45] Solmaz, R., Karda, G., Yazıcı, B., & Erbil, M. (2008b). Adsorption and corrosion inhibitive properties of 2-amino-5-mercapto-1,3,4-thiadiazole on mild steel in hydrochloric acid media. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 312, 7–17. DOI:10.1016/j.colsurfa.2007.06.035. http://dx.doi.org/10.1016/j.colsurfa.2007.06.03510.1016/j.colsurfa.2007.06.035Search in Google Scholar
[46] Solmaz, R., Altunbaş, E., & Kardaş, G. (2011). Adsorption and corrosion inhibition effect of 2-((5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl)phenol Schiff base on mild steel. Materials Chemistry and Physics, 125, 796–801 DOI:10.1016/j.matchemphys.2010.09.056. http://dx.doi.org/10.1016/j.matchemphys.2010.09.05610.1016/j.matchemphys.2010.09.056Search in Google Scholar
[47] Sugawara, H., & Ebiko, H. (1967). Dezincification of brass. Corrosion Science, 7, 513–523. DOI: 10.1016/s0010-938x(67)80090-8. http://dx.doi.org/10.1016/S0010-938X(67)80090-810.1016/S0010-938X(67)80090-8Search in Google Scholar
[48] Sürme, Y., Gürten, A. A., & Bayol, E. (2011). Corrosion behaviour of mild steel in presence of scale inhibitor in sulfuric acid solution. Protection of Metals and Physical Chemistry of Surfaces, 47, 117–120. DOI:10.1134/s2070205110051053. http://dx.doi.org/10.1134/S207020511005105310.1134/S2070205110051053Search in Google Scholar
[49] Uhlig, H. H. (1963). Corrosion and corrosion control: An introductionzto corrosion science and engineering (pp. 290). New York, NY, USA: Wiley. Search in Google Scholar
[50] Wang, X. M., Yang, H. Y., & Wang, F. H. (2010). A cationic gemini-surfactant as effective inhibitor for mild steel in HCl solutions. Corrosion Science, 52, 1268–1276. DOI:10.1016/j.corsci.2009.12.018. http://dx.doi.org/10.1016/j.corsci.2009.12.01810.1016/j.corsci.2009.12.018Search in Google Scholar
[51] Young, D. C. (2001). Computational chemistry: A practical guide for applying techniques to real world problems. New York, NY, USA: Wiley. 10.1002/0471220655Search in Google Scholar
[52] Zhang, R., & Somasundaran, P. (2006). Advances in adsorption of surfactants and their mixtures at solid/solution interfaces. Advances in Colloid and Interface Science, 123–126, 213–229. DOI:10.1016/j.cis.2006.07.004. http://dx.doi.org/10.1016/j.cis.2006.07.00410.1016/j.cis.2006.07.004Search in Google Scholar PubMed
[53] Zhang, Q., Gao, Z. N., Xu, F., & Zou, X. (2011). Adsorption and corrosion inhibitive properties of gemini surfactants in the series of hexanediyl-1,6-bis-(diethyl alkyl ammonium bromide) on aluminium in hydrochloric acid solution. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 380, 191–200. DOI:10.1016/j.colsurfa.2011.02.035. http://dx.doi.org/10.1016/j.colsurfa.2011.02.03510.1016/j.colsurfa.2011.02.035Search in Google Scholar
© 2012 Institute of Chemistry, Slovak Academy of Sciences
Articles in the same Issue
- Characterisation of VOC composition of Slovak monofloral honeys by GC×GC-TOF-MS
- Combustion-derived CdO nanopowder as a heterogeneous basic catalyst for efficient synthesis of sulfonamides from aromatic amines using p-toluenesulfonyl chloride
- Molybdate sulfonic acid: preparation, characterization, and application as an effective and reusable catalyst for octahydroxanthene-1,8-dione synthesis
- Enantioselective extraction of hydrophilic 2-chloromandelic acid enantiomers by hydroxypropyl-β-cyclodextrin: experiments and modeling
- Attrition of dolomitic lime in a fluidized-bed reactor at high temperatures
- Improvement of aquatic pollutant partition coefficient correlations using 1D molecular descriptors — chlorobenzene case study
- Mercury characterisation in urban particulate matter
- Thermal decomposition of lanthanide(III) complexes of bis-(salicylaldehyde)-1,3-propylenediimine Schiff base ligand
- Effect of hyamine on electrochemical behaviour of brass alloy in HNO3 solution
- Calorimetric determination of the effect of additives on cement hydration process
- Entrapment of ethyl vanillin in calcium alginate and calcium alginate/poly(vinyl alcohol) beads
- Facile synthesis of 3-substituted quinazoline-2,4-dione and 2,3-di-substituted quinazolinone derivatives
- Virtual screening of imidazole analogs as potential hepatitis C virus NS5B polymerase inhibitors
- A new phenanthroindolizidine alkaloid from Tylophora indica
Articles in the same Issue
- Characterisation of VOC composition of Slovak monofloral honeys by GC×GC-TOF-MS
- Combustion-derived CdO nanopowder as a heterogeneous basic catalyst for efficient synthesis of sulfonamides from aromatic amines using p-toluenesulfonyl chloride
- Molybdate sulfonic acid: preparation, characterization, and application as an effective and reusable catalyst for octahydroxanthene-1,8-dione synthesis
- Enantioselective extraction of hydrophilic 2-chloromandelic acid enantiomers by hydroxypropyl-β-cyclodextrin: experiments and modeling
- Attrition of dolomitic lime in a fluidized-bed reactor at high temperatures
- Improvement of aquatic pollutant partition coefficient correlations using 1D molecular descriptors — chlorobenzene case study
- Mercury characterisation in urban particulate matter
- Thermal decomposition of lanthanide(III) complexes of bis-(salicylaldehyde)-1,3-propylenediimine Schiff base ligand
- Effect of hyamine on electrochemical behaviour of brass alloy in HNO3 solution
- Calorimetric determination of the effect of additives on cement hydration process
- Entrapment of ethyl vanillin in calcium alginate and calcium alginate/poly(vinyl alcohol) beads
- Facile synthesis of 3-substituted quinazoline-2,4-dione and 2,3-di-substituted quinazolinone derivatives
- Virtual screening of imidazole analogs as potential hepatitis C virus NS5B polymerase inhibitors
- A new phenanthroindolizidine alkaloid from Tylophora indica
