明胶纳米颗粒稳定的Pickering乳液的制备及表征

Preparation and characterization of Pickering emulsion stabilized by gelatin nanoparticles

以B型明胶和京尼平为原材料,通过2次去溶剂结合京尼平交联固化明胶法制备得到明胶纳米颗粒。然后以明胶纳米颗粒为乳化剂,玉米油为油相,采用均质乳化法制备得到水包油型Pickering乳液。研究了明胶纳米颗粒的浓度、乳化时间、转速、水相pH值和盐离子浓度对Pickering乳液的影响。结果表明,明胶纳米颗粒呈表面光滑的球形颗粒,粒径约为186.7 nm,等电点约为6,三相接触角为76.6°。综合考察制备的Pickering乳液液滴的微观形貌和粒径,明胶纳米颗粒稳定的Pickering乳液的最佳制备工艺参数为:明胶纳米颗粒的浓度为20.0 mg/mL,乳化时间为90 s,乳化转速为13000 r/min,水相pH为8.0,NaCl浓度为50 mmol/L。最佳工艺下制备的Pickering乳液能够承受高于40%的剪切应变,表现出良好的稳定性。

Gelatin nanoparticles were prepared through a two-step desolvation method combined with genipin crosslinking.Then O/W Pickering emulsion was prepared by homogeneous emulsification method using gelatin nanoparticles as emulsifier and corn oil as the oil phase.The effects of gelatin nanoparticle concentration,emulsification time,rotation rate,pH of the aqueous phase,and salt ion concentration on Pickering emulsions were investigated.Results showed that gelatin nanoparticles were spherical particles with smooth surfaces.The particle size was about 186.7 nm.The isoelectric point of gelatin nanoparticles was about 6,and their three-phase contact angle was 76.6°.The morphology and size of droplets of Pickering emulsion were comprehensively investigated.The optimal preparation parameters of Pickering emulsion stabilized with gelatin nanoparticles were as below:the concentration of gelatin nanoparticles was 20.0 mg/mL,the emulsification time was 90 s,the emulsification speed was 13000 r/min,the pH of the aqueous phase was 8.0,and the concentration of sodium chloride was 50 mmol/L.Pickering emulsion prepared under the optimal process could withstand more than 40%shear strain,showing good stability.