Study Pickering Emulsion And Polymerization Stabilized By Modified Diatomite Particles

Pickering emulsions are stabilized by solid particle emulsifiers,which prevent the need for hazardous surfactants and provide the obtained emulsion superior stability over conventional surfactant molecules.In this work,Diatomite particles were chemically modified to regulate their hydrophilic-hydrophobic balances,and the use of the resulting particles to stabilize Pickering emulsions,and then composite materials with different structures were fabricated via the polymerization of the Pickering emulsions.Detailed contents were as follows:1.The surface properties of diatomite particles were successfully tailored by chemical modification with palmitoyl chloride.The properties of the resulting diatomite particles changed from the original hydrophilicity to hydrophobicity,leading to straightforward stabilization of oil-in-water-in-oil(O/W/O)Pickering double emulsions by a one-step emulsification process.Pickering double high internal phase emulsions(HIPEs)with an internal phase up to 80 vol%could be produced solely using the modified diatomite particles.Furthermore,using the O/W/O Pickering double emulsions as templates,the porous polymer particles were fabricated.In addition,it was demonstrated that the wide particle size distribution of diatomite particles and modified heterogeneity were the reasons for the formation of multiple emulsions.2.A new strategy based on Pickering emulsion polymerization to fabricate novel organohydrogels with antifreeze properties.Ethylene glycol(EG)is introduced into the aqueous phase of the Pickering high internal phase emulsion(HIPE)to effectively inhibit water from freezing.The resulting bicontinuous organohydrogels are prepared through simultaneous polymerization in the external and internal phases to provide enhanced mechanical properties and good hydrophilic-oleophilic properties.Furthermore,the organohydrogels are more stable than conventional hydrogels under ambient conditions and remain unfrozen and mechanically flexible down to-40?.3.The Pickering emulsion template method was proposed to control the surface wettability of polymer microspheres.Upon the dispersion of modified diatomite particles in the aqueous phase,a superhydrophobic surface was formed on the polymer microspheres via Pickering emulsion polymerization,with a water contact angle of 151°.When the initial dispersion location of the modified diatomite particles changed from water to oil,a hydrophilic/underwater superoleophilic surface with micro/nanoscale hierarchical structures formed on the polymer microspheres.This special wettability enabled the microsphere layer to serve as an adsorbent with underwater superoleophilicity,achieving efficient oil separation from various oil-in-water emulsions with high separation efficiency of>99.8%.4.Multifunctional composite microspheres were prepared based on Pickering HIPE polymerization for oil/water separation and dyes and heavy metal ions removal.The composite microspheres are lipophilic and hydrophilic under oil,and can achieve the separation of oil-water emulsion.1-Vinylimidazole(VIM)was introduced into the aqueous phase of the Pickering HIPE to effectively absorb heavy metal ions and dye during the process of oil/water emulsions separation.According to the results,the separation efficiency of various water in oil emulsions reaches 99.92%,and low concentration of MB and heavy metal ions(Cu2+?Pb2+?Eu3+?Nd3+)could be effective removal during separation process with high removal rate of>99.6%?5.Inverse Pickering emulsion was stabilized by modified diatomite particles instead of small molecular emulsifiers,and then zwitterionic sludge dehydrants were prepared based on the inverse Pickering emulsion polymerization.Compared with traditional emulsion,the Pickering emulsion system,reduced the amount of emulsifier,lowers the production cost and improves the production efficiency.The prepared zwitterionic sludge dehydrants has excellent dehydration performance for oil-based mud.