| Molecular self-assembly is a collective behavior produced by the synergistic effect of weak interactions between elementary particles in nanometer,micro or larger scale.The ordered supramolecular structure formed by self-assembly can bring optical,electrical,magnetic and other special properties to materials,and can be applied to the preparation of special materials.Therefore,it can be said that molecular self-assembly is the cradle of the next generation of new materials.To explore self-assembly behavior of molecules and howto obtain well-functionalized elementary particles effectively can help us design and synthesis high performance materials and understand life.Herein,we investigate self-assembly behavior of triphenylene-based side-chain discotic liquid crystalline polymers(SDLCPs)and summarize the factors that affect its self-assembly behavior.By investigating the polymer-coated nanoparticle self-assembly,we obtained well-defined patchy colloid particlesby changing the quality of solvent,length and number of tethered polymers.Dissipative particle dynamics(DPD)simulations were performed on a generic model of triphenylene-based SDLCPs to study how molecular weight,main chain,spacer and aliphatic tails,and incompatibility between mesogenic core and its substituents influence polymer self-assembly behavior.By changing the factors mentioned above,we obtained eight mesophases named according to the assembly of discogens-the aggregation of backbone and denoted as:hexagonal columnar-amorphous(Colh-Am),nematic columnar-amorphous(Colne-Am),nematic columnar-clustered(Colme-Clu),nematic columnar-columnar(Colne-Col),random columns-amorphous(Colran-Am),random columnar-clustered(Colran-Clu),amorphous-amorphous(Am-Am),spherical-amorphous(Sph-Am).We observed the intracolumnar self-assembling patterns based on the discrete columnar stack by checking the conformation of molecules,such as in phases Colh-Am,Colne-Am and Colne-Clu.But different packing modes were adopted in the phases of Colne-Col and Sph-Am.For SDLCPs,proper peripheral aliphatic tails provide mobility for discogens and promote mesophases,moderate to strong incompatibility between mesogenic cores and substituents are needed.Positive coupling effect prevails in SDLCPs with shorter spacers,and a critical degree of polymerization(DP)exists for them to form ordered columnar phases.These findings agree well with experimental results and may offer inspiring guidance for rational polymer design,preparation and further exploration in this promising field.The anisotropic colloidal particles are elementary particle of self-assembly.In recent years,various anisotropic colloidal particles which have different sizes,forms,and chemical or physical properties have been obtained.The adopted methods come form different fields,such as chemical,physical,biological,engineering,and material science.Anisotropic particles are similar to the behavior of "molecules" and "atoms"and they can be directed by their interactions to form ordered structures.Adjusting the aggregation morphology of polymers tethered on nanoparticle by changing the properties of solvents is a convenient way to construct anisotropic particles.We investigated the patterning of nanoparticle with polymer patches using theDPDmethod.By changing the reaction between polymer and solvent,size of nanoparticle,number and length of tethered polymers,we obatained colloid particles with various morphologies.According to the distribution and aggregation of polymers,they were classified into five types:core-shell,mesophase,patchy particle and compressed core-shell.When patchy particle have well-defined patches,they were called mono-patch,dual-patch,tri-patch,tetra-patch and multi-patch(the number of patch is larger than 4).These colloid particles with well-defined patches will serve as the elementary particles for self-assembly,and how to control the self-assembly process remains to be further studied. |
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