In order to obtain the gradient fluorinated/non-fluorinated polyacrylate latex blend films as cheap as possible

the fluorinated polyacrylate emulsion with small particle size was synthesized by bulk emulsion polymerization method

the acrylate copolymer emulsion with big particle size was synthesized by semicontinuous emulsion polymerization method

and then the fluorinated polyacrylate emulsion and the acrylate copolymer emulsion were mixed with a series of ratios (1/9

2/8

3/7

4/6

5/5).The blend latices were dried on clean glass at 20℃ and then annealled at 110℃/210℃ for some time (2~6 h).The effects of the fluorinated polyacrylate content on the gradient structure and surface property of the blend films were discussed.The content of fluorine on the film surface and the film section was analyzed by XPS

SEM-EDX.The surface properties and morphology were characterized by contact angle measurements and AFM.It was found that

while the content of fluorinated polyacrylate latex in the blend system was up to 30 wt%

the small and hard fluorinated polyacrylate particles were selectively gathered on the film-air interface after film-formation at room temperature

and the fluorine content increased from the film-glass interface to the film-air interface gradually in the blend films annealled 2 h at 110℃.The obtained gradient film has low surface free energy as the pure fluorinated polyacrylate and strong adhesion as the pure polyacrylate.The further increasing of fluorinated polyacrylate in the blend system helped the formation and enlargement of gradient structure

but the adhesion of film was decreased a little.The emulsion system with the content of fluorinated polyacrylate latex under 30 wt% was hard to form gradient structure.