“…The morphology of HAp nanoparticles also depends on additives, such as surfactant molecules [104,105] (cf micelle-templated method described in the next paragraph, and emulsion methods described in section 2.2.5), alcohol [106], amino acids [107][108][109], citrates [110,111], poly(acrylic acid) [112,113], poly(ethylene imine) [114,115], poly(ethylene oxide) (poly(ethylene glycol)) [116,117], poly(vinyl alcohol) [118,119] and biopolymers [119], mainly due to the inhibition of crystal growth by preferentially adsorbing the additives onto a HAp surface (a or c plane).…”