TY - JOUR
T1 - Ion distribution around a charged rod in one and two component solvents
T2 - Preferential solvation and first order ionization phase transition
AU - Okamoto, Ryuichi
AU - Onuki, Akira
N1 - Funding Information:
This work was supported by Grants-in-Aid for scientific research on Priority Area “Soft Matter Physics” and the Global COE program “The Next Generation of Physics, Spun from Universality and Emergence” of Kyoto University from the Ministry of Education, Culture, Sports, Science and Technology of Japan. The authors thank K. Yoshikawa, K. Nishida, T. Sumi, Y. Masubuchi, and Y. Yamasaki for valuable discussions.
PY - 2009
Y1 - 2009
N2 - In one and two component polar solvents, we calculate the counterion distribution around an ionizable rod treating the degree of ionization α as an annealed variable dependent on its local environment. In the two component case, we take into account the preferential solvation of the charged particles and the short-range interaction between the rod and the solvent. It follows a composition-dependent mass action law. The composition becomes heterogeneous around a charged rod on a mesoscopic scale, strongly affecting the counterion distribution. We predict a first order phase transition of weak-to-strong ionization for hydrophobic chains. This transition line starts from a point on the solvent coexistence curve and ends at an ionization critical point. The composition heterogeneity is long-ranged near the solvent critical point.
AB - In one and two component polar solvents, we calculate the counterion distribution around an ionizable rod treating the degree of ionization α as an annealed variable dependent on its local environment. In the two component case, we take into account the preferential solvation of the charged particles and the short-range interaction between the rod and the solvent. It follows a composition-dependent mass action law. The composition becomes heterogeneous around a charged rod on a mesoscopic scale, strongly affecting the counterion distribution. We predict a first order phase transition of weak-to-strong ionization for hydrophobic chains. This transition line starts from a point on the solvent coexistence curve and ends at an ionization critical point. The composition heterogeneity is long-ranged near the solvent critical point.
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U2 - 10.1063/1.3216518
DO - 10.1063/1.3216518
M3 - Article
C2 - 19739871
AN - SCOPUS:69949142342
VL - 131
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 9
M1 - 094905
ER -