Preparation And Application Researches Of MRF/PDMS Magnetoresponsive Liquid-Based Membranes

Magnetorheological elastomers as a class of functional materials are mainly composed of non-magnetic elastomer matrices and embedded magnetic particles,who possess excellent non-contact magnetic response properties.Liquid gating membranes as liquid-based membrane materials,which are constructed by a porous membrane that infiltrated with a capillary-stabilized gating liquid,show superior reversible switching ability,critical pressure adjustable capability,anti-fouling performance,drag reduction effect,etc.Combining the non-contact magnetic response of magnetorheological elastomers with liquid gating mechanism,we not only designed and built a stable magnetoresponsive liquid-based membrane system,but also studied its applications in the fields of multiphase separation and drug release.The main research contents and results are as follows:1.The investigations about the effect of magnetic component and doping amount of magnetorheological fluid(MRF)on the performance of polydimethylsiloxane(PDMS)-based magnetoresponsive elastomer films were conducted.The experimental results showed that films doped with MRF had excellent film-forming ability and magnetically actuated deformability,and samples containing 20 wt%,25 wt%,and 30 wt%MRF exhibited excellent magnetic and mechanical properties.Considering the cost,MRF/PDMS magnetoresponsive elastomer films with 20 wt%MRF content were selected to build magnetoresponsive liquid-based membranes.2.The MRF/PDMS magnetoresponsive liquid-based membrane could be fabricated from the magnetoresponsive elastomer film by laser cutting and infiltrating with a gating liquid.The wettability of different gating liquids on magnetoresponsive elastomer films and the interfacial energy of different configurations were investigated.Experimental results revealed that MRF/PDMS magnetoresponsive liquid-based membranes infiltrated with silicone oil had prominent stabilities,and the application of a magnetic field would not affect their stabilities.Moreover,the membranes also showed excellent anti-fouling performance.3.Taking advantage of the difference between the critical pressure of air and water through the MRF/PDMS magnetoresponsive liquid-based membranes filled with silicone oil,the separation system was set up for air-water separation experiments.Finally,we found that the magnetoresponsive liquid-based membranes successfully attained air-water separation in the absence of a magnetic field and in the presence of a magnetic field.More important,the required pressure under the magnetic field intensity of 2200 Gs was lower than the required pressure in the absence of a magnetic field,which could reach 23.1%of energy savings.4.A magnetoresponsive drug release device was designed and fabricated.After the leak test was completed,we used the bare membrane and the MRF/PDMS magnetoresponsive liquid-based membrane filled with silicone oil to successively performed drug release experiments.Compared with the bare membrane,the MRF/PDMS magnetoresponsive liquid-based membrane could fast and remotely release the drug under a lower magnetic field strength due to the lubrication of a gating liquid,and the drug release amount improved as the magnetic field strength increased.