Fig. 1
From: Unexpected stability of aqueous dispersions of raspberry-like colloids
One-step synthesis of raspberry colloids. a 2.0, 20.0 and 1.0 mmol of acrylate monomer (AM), styrene (St) and divinylbenzene (DVB) are polymerised in 50 mL of a water–ethanol mixture (80/20 v/v), containing 0.2 mmol 2,2′-azobis(2-methyl-propionamide) dihydrochloride (AIBA) as initiator at 70 °C. Raspberry particles are formed as cross-linked hybrid polymers with polyacrylate (PA) and polystyrene (PS) sections. b TEM image of the raspberry particle. c–e Mechanism of the one-step polymerisation approach for raspberry particles. AM-rich solution and St-rich heterogeneous monomer droplets coexist in the continuous phase at the beginning (c). Upon initiation, nanoscale PA-rich particles (created in dispersion polymerisation of dissolved monomers) and microscale PS-rich particles (resulting from soap-free emulsion polymerisation of heterogeneous monomer droplets) form in the same system (d), which are brought together in the presence of cross-linking agent of DVB, forming raspberry colloids (e). Images are not to scale
