Controllable Self-Assembly Of Plasmonic Micro/Nano-Ordering Architectures And Their Optical Properties

Plasmonic materials have always been the frontier and "hot spot" of nanomaterials research because of their unique surface plasmon resonance(SPR),and they are widely used in information technology,nanooptics,biomedicine and energy fields.With the deepening of interdisciplinary integration,the strategy of controlling the optical properties of nanounits based on size and morphology has been difficult to meet the needs of emerging fields,such as quantum topological optics,metamaterials(metasurfaces,superstructures),and so on.Many studies have shown that the ordered arrangement of the plasmonic micro/nano units can produce some unique optical properties,which are based on the near/far field coupling between the units.These optical properties inject new vitality into the in-depth study of plasmonic materials.However,the traditional "top-down" etching method is often limited by high cost,low efficiency,single structure and material,it is difficult to be popularized in the laboratories due to its high technical threshold.In contrast,the"bottom-up" self-assembly technology has the characteristics of low cost,rapid,batch and so on.It can realize the effective construction of plasmonic micro/nano-ordering architectures with various dimensions,structures and sizes.It provides an effective way for the researches and applications of optical properties of plasmonic micro/nano-ordering architectures.Although there have been many reports about the preparation of plasmonic micro/nano-ordering architectures based on self-assembly,it remains a challenge to develop simple,efficient,universal,and economical self-assembly strategies to realize the controllable construction of plasmonic micro/nano-ordering architectures with excellent performance.In this paper,gold nanoparticles are used as typical plasmon assembly units,aiming to develop new self-assembly methods and reveal the mechanism of self-assembly,so as to realize the controllable construction of plasmonic micro/nano-ordering architectures,and study the physical mechanism of near/far field coupling between units,and explore their potential applications.It is expected to provide the material basis and technical route for the commercialization of plasmonic micro/nano-ordering architectures.Based on this research idea,this paper has achieved some phased results:(1)Based on the electrostatic self-assembly strategy,the controllable construction of the two-dimensional Janus PS@Au raspberry photonic crystal array is realized,and its near-infrared surface-enhanced raman scattering(NIR-SERS)performance is explored.Aiming at the difficulty of realizing strong absorption in near infrared band by LSPR near field coupling of two-dimensional gold nanoarrays,a strategy of photonic band gap to enhance near infrared absorption of two-dimensional gold ordering architecture is proposed,and the NIR-SERS enhanced effect of colloidal photonic-crystal loaded gold Janus ordering structure is realized.(2)The batch and high purity of controllable separation preparation of plasmonic dimers with hetero-structure is realized by using the strategy of van der Waals force self assembly combined with gel electrophoresis.The internal mechanism of successful separation of oligomers is revealed:the difference in kinetic energy loss caused by random inelastic collisions between oligomers and gel networks.The influence of the shape,size,volume and mass of nanoparticles on the separation results is studied.The decisive role of mass in the gel electrophoresis separation of metal nanoparticle oligomers is determined by experiments and COMSOL simulation.High purity Au/Ag core-shell nanocubes-Au nanospheres heterodimers are prepared.This study provides an efficient and stable method for the preparation of complex metal nanoparticle oligomers.(3)Based on domain limited self-assembly combined with laser irradiation,a strategy for the fast and controllable construction of hexagonal non-packed and ordered ultra-smooth gold conductive microsphere array is developed.The mechanism of transformation from gold superstructure to gold microsphere is revealed:laser induced "heating-melting-fusion" mechanism.The effects of laser intensity,irradiation time,pulse output frequency and environmental media on the formation of gold microspheres are investigated.The results show that laser intensity is the key factor for the formation of complete and smooth gold microspheres.The preparation of plasmon alloy microspheres is realized by simply mixing metal nanoparticles of different materials.This research provides the material basis for miniaturization and integration of electronic devices.(4)Based on the transient emulsion self assembly system,a new method of transient emulsion layer assembly ordering architectures is developed,and the controllable mark printing construction of plasmonic micro/nano-ordering architectures is realized.The mechanism of precise control of heterogeneous structures is revealed:the synergistic/competitive relationships between hydrophilic/hydrophobic and confined domain effect.The effect of hydrophilicity/hydrophobicity,confined domain effect and concentration of nanoparticles on the evolution of hierarchical heterostructure patterns are studied,and the basic law of selective deposition of secondary structures on hydrophilic points is determined.This study provides a new strategy for the preparation of heterogeneous arrays.In summary,in this paper,some construction methods of plasmonic micro/nano-ordering architectures are developed based on gold nanoparticles as the basic assembly units,self-assembly mechanisms are explored,and related properties are studied,it provides technical supports for the researches and applications of plasmonic micro/nano-ordering architectures.