Mechanically stable thermo-reversible gels of the liquid-crystal LC-E7 with
1,3:2,4-Di-O-benzylidene-D-sorbitol (DBS) form white light-scattering film
s that are reversibly switchable to a clear state by AC electric fields. It
is established that the light-scattering nature of DBS/LC-E7 gels is an in
trinsic material property that originates from the occurence of a monotecti
c-type point ("mesotectic") at very low DBS-concentration in the phase diag
ram of the DBS/LC-E7 system.