Porous polymeric
microspheres are an emerging class of materials,
offering stimuli-responsive cargo uptake and release. Herein, we describe
a new approach to fabricate porous microspheres based on temperature-induced
droplet formation and light-induced polymerization. Microparticles
were prepared by exploiting the partial miscibility of a thermotropic
liquid crystal (LC) mixture composed of 4-cyano-4′-pentylbiphenyl
(5CB, unreactive mesogens) with 2-methyl-1,4-phenylene bis4-[3-(acryloyloxy)propoxy]
benzoate (RM257, reactive mesogens) in methanol (MeOH). Isotropic
5CB/RM257-rich droplets were generated by cooling below the binodal
curve (20 °C), and the isotropic-to-nematic transition occurred
after cooling below 0 °C. The resulting 5CB/RM257-rich droplets
with radial configuration were subsequently polymerized under UV light,
resulting in nematic microparticles. Upon heating the mixture, the
5CB mesogens underwent a nematic–isotropic transition and eventually
became homogeneous with MeOH, while the polymerized RM257 preserved
its radial configuration. Repeated cycles of cooling and heating resulted
in swelling and shrinking of the porous microparticles. The use of
a reversible materials templating approach to obtain porous microparticles
provides new insights into binary liquid manipulation and potential
for microparticle production.