+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Phase equilibria in polydisperse nonadditive hard-sphere systems

, : Phase equilibria in polydisperse nonadditive hard-sphere systems. Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics 78(2 Pt 1): 021202-021202

Colloidal particles naturally exhibit a size polydispersity that can greatly influence their phase behavior in solution. Nonadditive hard-sphere (NAHS) mixtures are simple and well-suited model systems to represent phase transitions in colloid systems. Here, we propose an analytical equation of state (EOS) for NAHS fluid mixtures, which can be straightforwardly applied to polydisperse systems. For positive values of the nonadditivity parameter Delta the model gives accurate predictions of the simulated fluid-fluid coexistence curves and compressibility factors. NPT Monte Carlo simulations of the mixing properties of the NAHS symmetric binary mixture with Delta>0 are reported. It is shown that the enthalpy of mixing is largely positive and overcomes the positive entropy of mixing when the pressure is increased, leading to a fluid-fluid phase transition with a lower critical solution pressure. Phase equilibria in polydisperse systems are predicted with the model by using the density moment formalism [P. Sollich, Adv. Chem. Phys. 116, 265 (2001)]. We present predictions of the cloud and shadow curves for polydisperse NAHS systems composed of monodisperse spheres and polydisperse colloid particles. A fixed nonadditivity parameter Delta > 0 is assumed between the monodisperse and polydisperse spheres, and a Schulz distribution is used to represent the size polydispersity. Polydispersity is found to increase the extent of the immiscibility region. The predicted cloud and shadow curves depend dramatically on the upper cutoff diameter sigmac of the Schulz distribution, and three-phase equilibria can occur for large values of sigmac.


PMID: 18850822

DOI: 10.1103/PhysRevE.78.021202

Other references

Nashold, J.R.B.; Oakes, W.J.rry; Friedman, H.S.; Halperin, E.C.; Soo, M.; Hockenberger, B.; Fuller, G.N.; Tien, R., 1994: Management of pineal non-germinoma germ cell tumor with residual teratoma and normal alpha-fetoprotein. A 16-year-old white male presented with multiple abnormal extraocular movements secondary to an enhancing pineal tumor. Subtotal resection of the lesion revealed a mixed malignant germ cell tumor. The preoperative serum alpha-fetoprotein (AFP) was...

Ofman, J.J.; Fullerton, S.C.; Reyes, E.B.; Shaw, M.J.; Grogg, A.; Sadik, K., 2000: Development and validation of a screening instrument for gastroesophageal reflux disease. American Journal of Gastroenterology 95(9): 2637, September

Goulden, J.D.; Salter, D.N., 1977: An automated optical emission spectrometer for 15N analysis. Proceedings of the Nutrition Society 36(3): 132a-132a

Forst, T.; Hanefeld, M.; Jacob, S.; Moeser, G.; Schwenk, G.; Pfützner, A.; Haupt, A., 2013: Association of sulphonylurea treatment with all-cause and cardiovascular mortality: a systematic review and meta-analysis of observational studies. We conducted a meta-analysis of cohort and case-control studies to evaluate all-cause and cardiovascular (CV) mortality of patients with type 2 diabetes mellitus (T2DM) who received sulphonylurea (SU) treatment, when compared to any other diabetes...

Hamada, K.; Nishida, T.; Yamauchi, K.; Fukushima, K.; Kondo, R.; Tsutsumi, Y., 2004: 4-Coumarate:coenzyme A ligase in black locust (Robinia pseudoacacia) catalyses the conversion of sinapate to sinapoyl-CoA. 4-Coumarate:coenzyme A (CoA) ligase (4CL, EC in crude enzyme preparation from the developing xylem of black locust (Robinia pseudoacacia) converted sinapate to sinapoyl CoA. The sinapate-converting activity was not inhibited by other cin...

Akkermans, A.D.L.; Van Elsas, J.D.rk; D.B.uijn, F.J., 1995: Molecular microbial ecology manual. Recent developments in molecular biology can be employed to identify microbes directly from their DNA/RNA without first having to culture and isolate the organisms. This loose-leaf manual houses a collection of these new techniques. They are espec...

Chau, H.; Tenenhouse, H.S., 2001: Renal phosphate wasting and hypercalciuria in Npt2 knockout mice are associated with nephrocalcinosis. Journal of the American Society of Nephrology 12(Program and Abstract Issue): 751A, September

Bernstein, D.I.; Karnani, R.; Murphy, K.; Bernstein, C.; Berendis, B.; Hamilton, R.; Biagini, R.; Yeang, H.Y., 2001: Percutaneous sensitization to Hev b proteins in health care workers reporting allergic reactions to natural rubber latex gloves Preliminary results. Journal of Allergy & Clinical Immunology 107(2): S322, February

Richter, J.G.; Becker, A.; Koch, T.; Nixdorf, M.; Schacher, B.; Monser, R.; Specker, C.; Alten, R.; Schneider, M., 2009: Internet use in rheumatology outpatients in 2006: gender less important. Exploring patients' Internet use, their online needs and requirements, expectations and attitudes towards the Internet is mandatory to effectively provide interactive online applications and information. Within a prospective study, 153 consec...

Lee,; Liu,; Jan, I Shiow; Chang, T.C.un; Kuo,, 2002: Cytologic patterns of fine needle aspiration of Hashimotos thyroiditis. Acta Cytologica 46(1 Supplement): 168, January-February