Preferred Label : membrane sites;
Detailed label : membrane sites in an ion-selective electrode;
IUPAC definition : Membranes frequently contain built-in 'fixed' charged sites (e.g. immobile –(SO sub
3 /sub sup class minus /sup ) in polystyrenesulfonate), or intentionally added,
hydrophobically trapped, 'mobile' sites [e.g. tetraphenylborate in plasticized poly(vinyl
chloride)]. Such membranes with charged sites are named sited membranes. Ions of opposite
sign in the membrane are 'counter-ions'. Ions of the same sign as sites are not present
in significant quantities, and are co-ions. Sited membranes are 'permselective' to
counter-ions i.e. only counter-ions exchange into the membrane and therefore have
some mobility in the membrane bulk.;
Origin ID : M03826;
See also
Membranes frequently contain built-in 'fixed' charged sites (e.g. immobile –(SO sub
3 /sub sup class minus /sup ) in polystyrenesulfonate), or intentionally added,
hydrophobically trapped, 'mobile' sites [e.g. tetraphenylborate in plasticized poly(vinyl
chloride)]. Such membranes with charged sites are named sited membranes. Ions of opposite
sign in the membrane are 'counter-ions'. Ions of the same sign as sites are not present
in significant quantities, and are co-ions. Sited membranes are 'permselective' to
counter-ions i.e. only counter-ions exchange into the membrane and therefore have
some mobility in the membrane bulk.
