Dynamic Vapor Sorption (DVS) is a gravimetric sorption technique that measures how quickly and how much
of a solvent is absorbed by a sample: such as a dry powder absorbing water. It does this by varying the vapor
concentration surrounding the sample and measuring the change in mass which this produces. Water vapor is most
commonly used, but it is also possible to use a wide range of organic solvents.
Sorbtion rates have traditionally been evaluated by storing samples in sealed jars containing saturated
salt solutions of established relative humidity and then regularly weighing these samples
until equilibrium is reached. Dynamic Vapor Sorption provides a number of advantages over
this method:
(i) Due to optimized vapor flow, reduces the time required to reach
equilibrium, measured in minutes rather than days. Simultaneously the dynamic flow of moisture reduces
the need for large sample sizes, requiring only a few milligrams of sample.
(ii) Due to the dynamic flow of vapor, the sample never needs to be removed from the instrument,
eliminating errors and contamination associated with removing samples from storage containers in previous
methods.
(iii) The technique allows for kinetic water sorption/desorption data to be collected in real time,
which is impossible in static methods.