Research For Construction And Performance Of Superhydrophobic Surface Via Micro-nano Multiscale Particles

Superhydrophobic materials have a series of application fields,including that anti-fouling,self-cleaning,anti-icing,anti-biological adhesion,anticorrosion,reduction of flow resistance,microdroplet transfer,water collection and etc.Thus,it has received attention from researchers and engineering technicians.According to analysis results of microcosmic rough structure and chemical composition with low surface energy in natural superhydrophobic surface with“lotus effect”or“rose petal effect”,hierarchy difference and micro or nano-scale gaps are the keys of controlling for water adhesion behavior of superhydrophobic surface.At present,micro-nano multiscale particles containing high hierarchy roughness,which can ease to adjust structure morphology and chemical composition,have been applied to construction of superhydrophobic surface with diverse water adhesive force.However,in most cases,micro-nano multiscale particles are formed via physical adsorption or chemical bonding between micro-scale structure and nano-scale structure,existing complicated construction process,dependent on hydrophobic modification,weak physico-mechanical property,poor durability of superhydrophobicity.In this research,based on developing a construction method for hierarchical rough structure-controllable micro-nano multiscale particles,aiming at realizing simultaneous accomplishment for stable formation and low surface energy treatment,further the water adhesion behavior of superhydrophobic surface constructed by micro-nano multiscale particles without post-modification can change from high adhesion state to low adhesion state.The research content was as follows:hollow polymer microspheres were used as micro reactors,reactive monomers or nanoparticles were loaded in hollow microspheres,the monomers within the microspheres initiated polymerization as well as fixation of nanoparticles on the microspheres surface,micro-nano multiscale particles were constructed using“bottom-up”method,and water adhesive force of superhydrophobic surface constructed by micro-nano multiscale particles was controlled by adjusting hierarchical rough structure morphology.Moreover,the micro-nano multiscale particles were applied as structural units for building superhydrophobic surface with diverse water adhesive force,and its application performances were investigated.Additionally,the special reaction principles of hydrophobic polymer nanoparticles participated in construction of micro-nano multiscale particles were found.Using it as a base,new types of superhydrophobic polymer bulk materials and cellulose sheet materials were fabricated,and its application of multifunction was also investigated in this research.This main research contents and conclusions are mainly focus on the following areas:?1?Hollow polymer microspheres were fabricated via template-based method.The fabrication route was as follows:synthesis of VTES-modified SiO₂ particles by sol-gel method,preparation of core-shell SiO₂@P?S-DVB?particles by dispersion polymerization and chemical etching of VTES-modified SiO₂ cores by NaOH solution,thus hollow P?S-DVB?microspheres were prepared.The morphology of hollow P?S-DVB?microspheres could be controlled by adjusting the amounts of DVB,AIBN and VTES,and the fabrication process of regular hollow P?S-DVB?microspheres with round-ball-like shape was investigated.Based on the above method,monomer TFEMA was added into the reaction process,after that,hollow P?S-DVB-TFEMA?microspheres were fabricated.Because of micro limited space used for chemical conversion was existed in hollow microspheres,which could be used as micro reactors to construct micro-nano multiscale particles.?2?Based on hollow P?S-DVB-TFEMA?microspheres as micro reactors,according to the principle of like dissolves like,micro-nano dual-scale structural material surface formed by RPs was prepared by absorption of St,EDGMA and AIBN into hollow P?S-DVB-TFEMA?microspheres and then nanoscale corona P?S-EDGMA?protrusions were in-situ grafted onto the core microscale structural microspheres shell from the inside out.The micro-nano dual-scale structural material surface formed by RPs had superhydrophobicity with high water adhesive force.Mathematical analysis of theoretical model for the micro-nano dual-scale structural material surface formed by RPs was carried out,which theoretical results corresponded well to experimental data.Because of results from stability test,the superhydrophobic surface with high water adhesive force constructed by robust RPs had good durability.By using oily fluorescent dye and according to the same“bottom-up”method,micro-nano dual-scale structural material surface formed by RPs with fluorescent effect was prepared,which possessed with superhydrophobicity with high water adhesive force,thus it was used for micro-droplet transportation with high visibility in UV dark box.?3?NCs nano granules were synthesized via 1,4 conjugate addition reaction of 5Acl,BPEI and OTCA in tetrahydrofuran system,and NCs nano granules with different morphology and size were prepared by adjusting the amount of BPEI.Under the stirring condition and based on the principle of like dissolves like,St,EDGMA,AIBN were absorbed into the cavity of hollow P?S-DVB-TFEMA?microspheres and in-situ capping of NCs nano granules onto the microspheres surface simultaneously;after thermal initiation,nanoscale P?S-EDGMA?protrusions were formed onto the microscale structural microspheres shell from the inside out,and then NCs deposits were also fixed on the microspheres surface,thus the MHPs were fabricated.Moreover,hierarchical rough structure of MHPs was controlled by changing morphology and size of surface fixed NCs nano granules,hence the wettability and the water adhesion behavior of superhydrophobic surface constructed by MHPs was tuned.The MHPs with appropriate sized NCs nano granules were used to fabricate superhydrophobic cotton fabric surface with low water adhesive force,exhibiting lotus leaf-like anti-fouling property.After high strength cyclic abrasion,cotton surface constructed by MHPs still had high static water contact angle,and MHPs could maintain structural integrity,exhibiting good abrasion resistance and mechanical stability.?4?According to hollow P?S-DVB?microspheres as micro reactors and the principle of like dissolves like,during the stirring process,St,EDGMA,AIBN were absorbed in the internal hollow microspheres,as well as simultaneous capping of NCs nano granules and nanoscale inorganic pigments on the surface of microspheres;under the heating condition,P?S-EDGMA?corona protrusions were formed on the microspheres shell from the inside out after polymerization of monomers within hollow microspheres,further fixing deposits of NCs nano granules and nanoscale inorganic pigments on the surface of microscale structural microspheres,obtaining SLPs with complex structure hierarchy.The SLPs with different color could be prepared by mixed-color effect between yellowing produced from St reacted with NCs and added nanoscale inorganic pigments.By virtue of the heat bonding method,the prepared SLPs were fixed on the surface of the cotton fabric to form colored SRF with adhesive back surface.The prepared SRF could be readily adhered on various substrates,endowing the underlying substrates with superior self-cleaning property and water-impact resistance.After treatments under extreme conditions including cyclic abrasion,strong acid and alkali,water immersing,high temperature,still showing the treated SRF achieved stable and durable superhydrophobicity with low water adhesive force.?5?In view of fabrication principle of NCs nano granules for constructing MHPs and SLPs,and the influence of reaction conditions on physical and chemical property for NCs was investigated.On this basis,superhydrophobic NCs bulk was fabricated via a gelation reation involving 5Acl and BPEI in alcohols solvent,follow by modification with OTCA.The synthesized pile-up granule size in the NCs bulk was controlled by regulating the addition of the BPEI and the types of reactive solvents,thus microstructure-controllable superhydrophobic NCs bulk was obtained.Inorganic nanoparticles were compounded into the controlled absolute ethanol-based NCs gel system to construct multifunctional organic/inorganic hybrid superhydrophobic NCs bulk,including a magnetic NCs bulk used for magnetically controlled oil-water separation,colored NCs chalk for fabricating a chromatic superhydrophobic coating.Additionally,a superhydrophobic NCs elastomer was prepared in pentanol and could store air under water.?6?Natural polyamino compounds were existed in nature,which could participate in 1,4conjugate addition reaction instead of BPEI.By virtue of mixed-color effect between the OCS/APTES aminated yellow pulp and reactive dyes,and then 1,4 conjugate addition reaction of 5Acl and OTCA was carried out onto mixed-color amino-pulp surface to form hierarchical rough composite structure,oily pen writable superhydrophobic colored cellulose sheet was fabricated via squeezing-drying method.Squeezing the hydrophilic colored cellulose filter cake covered on undried superhydrophobic yellow cellulose sheet could form wetting asymmetric cellulose sheet with double-color surface after drying,which could be used for selective oil-water separation.Furthermore,after CS cooperating with APTES to proceed with amination treatment of cellulose pulp,the cellulose sheet with both superhydrophobicity and fluorescence produced from UV excitation was prepared via the above-mentioned 1,4 conjugate addition reaction and then treatment of squeezing-drying.Meanwhile,such this anti-wetting cellulose sheet with UV photoluminescence exhibited strong fluorescence intensity and outstanding resistance to fluorescence quenching,which could be applied in durable fluorescence-labelled.