Colloid (sol) particles have a diameter between 1 and 1000 nanometers, approximately. If a sol particle, 275 nm in diameter, were compared to a water molecule, 0.275 nm in diameter, it would be 275 / 0.275 = 1000 times the diameter of a water molecule. Since volume is a cubic function of diameter, the sol particle would be 1,000,000,000,000 (one trillion) times the sol particle's volume and therefore, one trillion times its mass (Patterns in Fluid Flow Paradoxes., 1980; pp. 73-74 and Simple Harmonics, 2015: pp. 16-17, by G. Hamilton).
Sir Isaac Newton would roll over in his grave if he heard that modern scientists accept that which defies his principles relating to momentum exchange physics.
Furthermore, Brownian motion has been related to thermodynamics. Motion created in fluids by heat results in convection currents with gently curved paths, not abrupt sharp zigzag changes in direction.