caa a22 4500 475764951 CHVBK 20180406123603.0 cr unu---uuuuu 170329e20000201xx s 000 0 eng 10.1007/s003960050029 doi (NATIONALLICENCE)springer-10.1007/s003960050029 Polystyrene particles with proton-ionisable groups: pH-dependent stability of latices with weakly acidic groups [Elektronische Daten] [S. Ottow, R. Zimehl]  Results of colloid chemical characterisation and stability measurements on electrostatically stabilised latex dispersions made from emulsions of styrene and 4,4′-azobis-(4-cyanovaleric acid) are reported. The deviant stability of the hydrophobic polystyrene particles at low pH and low ionic strength is related to a proton "tunable” hydration layer surrounding weakly charged particles. The idea implies the formation of a polymer-supported surface phase that does not have any clear boundary, either towards the polymer moiety or in the direction of the bulk solution. The formation of the surface phase is controlled by Coulombic, hydrophobic and van der Waals interactions and by the contribution from the water structure at the hydrophobic and hydrophilic domain of the polymer particles. Negative charges on the hydrophobic surface badly interfere with the water structure at the hydrophobic moiety of the particle, whereas positive or uncharged surface groups do not damage the balance of free and clustered water molecules at the interface. Because the hydrophobic nature of the surface changes with the degree of dissociation of the surface charges, the degree of hydrophobicity of the carboxylic latices can be adjusted by changing the pH; therefore, it may be concluded that the hydrated and discharged carboxylic particle is apparently more hydrophobic relative to the ionised one. Thus, our concept can also explain differences in the hydrophobicity of colloidal polymer particles. Springer-Verlag Berlin Heidelberg, 2000 Key words Latices nationallicence Electrostatic stabilization nationallicence Coagulation nationallicence Water structure nationallicence Tunable ionization nationallicence Ottow S. Institute of Inorganic Chemistry University of Kiel Olshausenstrasse 40 D-24098 Kiel Germany e-mail: r.zimehl@email.uni-kiel.de Fax: +49-431-880 1520, DE aut Zimehl R. Institute of Inorganic Chemistry University of Kiel Olshausenstrasse 40 D-24098 Kiel Germany e-mail: r.zimehl@email.uni-kiel.de Fax: +49-431-880 1520, DE aut https://doi.org/10.1007/s003960050029 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s003960050029 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ottow S. Institute of Inorganic Chemistry University of Kiel Olshausenstrasse 40 D-24098 Kiel Germany e-mail: r.zimehl@email.uni-kiel.de Fax: +49-431-880 1520, DE aut NATIONALLICENCE 700 1- Zimehl R. Institute of Inorganic Chemistry University of Kiel Olshausenstrasse 40 D-24098 Kiel Germany e-mail: r.zimehl@email.uni-kiel.de Fax: +49-431-880 1520, DE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer