| Because of its high porosity,porous ceramics also have unique physical and chemical properties of ceramic materials,which are widely used in various fields,such as separation and filtration,sound insulation,catalyst,chemical filling,chemical sensors and biomedicine.It is applied in the field of separation and filtration,and can realize the precision filtration and physical separation of various media?In view of this,the biomimetic porous ceramic membrane with special wettability was prepared by using alumina ceramic material and the lotus leaf effect in nature,and through Direct Ink Writing,the construction of more complex porous ceramic components.At the same time,the bionic diaphragm prepared by mould forming is applied in the field of oil-water separation and antibacterial filtration.It is expected that the introduction of super-infiltration theory combined with traditional ceramic materials can provide an important application direction for the separation of ceramic film technology.Based on the requirements of Direct Ink Writing,molecular modification,powder design,material construction and biomimetic application are systematically studied from the design of chemical modification of powder surface.the modification mechanism of powder molecular particles is based on the hydrogen bonding of Lewis acid-base reaction.The micro-nano system of ceramic paste based on "phase separation" of oil and water was constructed by selfassembly of emulsion-assisted templates by emulsification of surfactant polyvinyl alcohol.The results show that the slurry presents different response states at different p H values.As the p H value increases,the viscosity and liquid state of the suspension show a sinusoidal distribution,and the emulsion foaming can be realized in the p H range of about 3?6,and the printing slurry can be prepared.During the emulsification interval,the viscosity of the slurry showed positive correlation with the increase of p H and stirring time,and the average pore size of the prepared samples showed a negative correlation decrease.For interconnected pores between macroporous pores,it is related to the amount of surfactant added.In view of this,the control window of pore behavior between macroporous and interconnected pore was established.This kind of porous ceramic structure with relatively adjustable pores and relatively well-distributed "phase separation" is a powerful guarantee for the lightweight and high-strength properties of the membrane matrix.The porous ceramic matrix is composed of interconnected pores and macropores with high density,and its compressive strength can be as high as 120 MPa,while the porosity reaches 74.3%.Based on the above results,the biomimetic macroporous ceramic membrane materials were prepared by using the low surface energy material polydimethylsiloxane to modify the membrane surface,which was applied in the field of oil-water separation.The results show that the separation efficiency is over 99.6%,and it can keep high efficiency separation performance and good contact angle value after grinding wear test.Its excellent surface superhydrophobicity and low adhesion are the effective guarantee of diaphragm application performance.The average water contact angle is 152.97° by static measurement and the advancing and receding angles are 168.30° and 148.02° respectively.Dynamic measurement shows that the average sliding angle is 4.50°.Bounce at least 5 times when free-fall droplets impact dynamically at 1.414 m/s speed,but the droplets seeped into the membrane within 2ms.All of these fully characterized the excellent super wettability of the membrane interface.Based on the above research results,the precursor method is used to deposit the zinc oxide precipitate layer,and the free zinc ion is used to realize the antibacterial function of the interface.Under the cover of the hydrophobic layer,the antibacterial filtration and separation are realized.The results showed that the membrane samples had bacteriostatic effect.The separation efficiency of oil and water is also higher.Especially in the separation of acid-base liquid,the separation efficiency still reaches 99%.These all show that the designed interface has good acid and alkali resistance.The porous alumina ceramic membrane material was prepared by the combination of emulsion self-assembly and wettability theory.It can solve many key problems in the field of oil-water separation.Such as poor mechanical stability,poor wear resistance,fragile microscopic characteristics,low oil pollution resistance,poor recyclability and so on.At the same time,it is expected that this method can provide a feasible methodology for porous application and interface design of other materials. |
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