This study analysed and compared the spreading processes of liquid over a solid (or
liquid over an immiscible liquid) an
d to solid particle aggregates over a liquid. These
two processes are fundamentally different in their physical nature. Thermodynamic
analysis of the two different spreading processes showed that the “spreading
coefficient of solid over liquid” proposed pr
eviously
[8]
is invalid, as it does not
capture the actual physical process. Other factors, including the Marangoni effect due
to temperature and liquid surface tension gradients, are likely to be the more dominant
driving forces which cause the initial mo
vement of solid particles over the liquid
surface. Further research efforts are required to identify and analyse powder spreading
driving force