Structure Formation in Solution: Ionic Polymers and Colloidal Particles - Softcover

Structure Formation in Solution : Ionic Polymers and Colloidal Particles

Taschenbuch. Zustand: Neu. Druck auf Anfrage Neuware - Printed after ordering - 1. 1 Macroionic Systems and the Scope of the Book Inthepresentmonograph,wewilldiscussionicpolymersolutionsandcolloidal dispersions. When these substances are dissolved into a solvent, they produce ionicspecies havinglargemolecularweightsandtheir counterions. We knowa variety of naturally occurring ionic polymers and chemically synthesizedc- pounds. Examples of the former are nucleic acids and some proteins, which playanimportantroleinbiologicalsystems. Examplesofsyntheticionicpo- mers are polyacrylic acid (PAA), polystyrenesulfonic acid (PSS) and poly- lylamine (PAAm). PAAisahighpolymer,inwhichmacrylicacidmoleculesCH =CH(COOH) 2 arelinearlypolymerizedby covalent bonds. Thenumber mis calledthe degree 3 of polymerization and is usually of the order of 10 . When PAA is dissolved in a dissociating solvent like water, anionic macroions and counterions are produced. In the following scheme, the counterions are protons but they may + be metal cations such as Na : CH CH CH CH 2 2 + + mH COOH COO m m PAA PAA anion Counterions. PAAm is a cationic polymer and dissociates into PAAm cations and anionic counterions as shown below: CH CH CH CH 2 2 +mHCl +mCl + CH NH CH NH 2 2 2 3 m m PAAm PAAm cation Counterions. 2 1 Introduction + In the case of NaCl, it dissociates into Na and Cl , which both have low molecular weights. On the other hand, PAA anions and PAAm cations have 3 highmolecularweights. Ifmis10 ,onepolymerion(macroion)hasananalyt- 3 + icalchargenumberZ of10 ,whichisexceedinglylargerthan1forNa . Artikel-Nr. 9783642427701

Verkäufer kontaktieren