PROBLEM TO BE SOLVED: To provide a simple method for modifying powder particle surface, a method for preparing a Pickering emulsion in various emulsified states, and a novel Pickering emulsion.SOLUTION: The method for modifying powder particle surface involves immersing the powder particles in an oil solution having an oxygen atom in the molecular structure. An emulsion state adjustment method comprises a step of modifying the powder particle surface using the method for modifying powder particle surface, and a step of adjusting the ratio of the oil and water phases.EFFECT: The powder particle surface can be simply modified, and a Pickering emulsion in various emulsified states can be prepared. In the method for modifying powder particle surface it is preferable for the surface of the powder particle to have a hydroxyl group and/or at least a silanol group, and for the powder particle to be a metal particle comprising titanium oxide.SELECTED DRAWING: None【課題】簡易に粉体粒子表面を改質する方法、多様な乳化状態のピッカリングエマルションの調製方法及び新規のピッカリングエマルションの提供。【解決手段】粉体粒子を、分子構造中に酸素原子を有する油剤に浸漬させる粉体粒子表面の改質方法。該粉体粒子表面の改質方法を用いて粉体粒子表面を改質する工程と、油相と水相の割合を調整する工程とを備える、乳化状態の調整方法。【効果】簡易に粉体粒子の表面を改質することができ、様々な乳化状態のピッカリングエマルションを製造できる。前記粉体粒子がその表面に水酸基を有すか及び/又は少なくともシラノール基を有することが好ましい、金属粒子で、酸化チタンを含む粉体粒子であること好ましい、紛体粒子の表面の改質方法。【選択図】なし
