Particle composition, film, optical lens, diffractive optical element, ion conductive membrane, battery separator film, secondary battery, circuit board, and diaphragm

A particle composition comprising an aromatic polyamide and/or an aromatic polyamic acid,

• wherein, rA/rB is larger than 1, and rB is 100 nm or more and 10,000 nm or less,
• in which
• rA (nm) is an average hydrodynamic radius of particles as measured by a dynamic light scattering method in an aqueous dispersion containing said particle composition at a concentration of 100 ppm by mass, and
• rB (nm) is said average hydrodynamic radius after subjecting the aqueous dispersion to an ultrasonic treatment.