Study On Crystal Morphology And Self-assembly Of Photoinitiator XBPO

Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide(XBPO)is a UV photoinitiator with a high initiation efficiency.The focus of XBPO research has been solely on its synthesis and efforts to study its morphology,polymorph and crystallization process have not been reported.In this study,the crystal habits and attachment behavior of XBPO were deeply investigated through experiments combined with computational simulations.Furthermore,the crystallization process and selfassembly of XBPO were explored to elaborate the crystal nucleation and growth mechanism in terms of the molecular diffusion and then a new crystallization process was developed to improve the product performance and productivity of XBPO.Overall,this research has theoretical and practical value.The crystal habits of XBPO in different solvents were predicted by molecular dynamics simulation and an affinity degree model was proposed to quantitatively analyze the solvent effect on crystal faces.Results indicate that the relationship between solvent molecules and the crystal surface can lead to the anisotropic growth of crystals.Meanwhile,the crystal morphology in acetone is preferred,which could guide solvent selection during the crystallization process of XBPO.In addition,the aggregation behavior of XBPO crystals was studied by quantum chemical computations and molecular dynamics simulations.It was found that the attachment behavior appears on the highest energy density surface(1 0 0)with a specific attachment angle(?=0�)and high polar solvents can reduce the aggregated behavior.By studying the crystallization process of XBPO,antisolvent with high viscosity was used to control the nucleation and growth of crystals in the antisolvent crystallization process.The results showed that new polymorph with good dispersion,no aggregation and large particle size was obtained,which also improved the absorption and initiation properties of products.Moreover,four antisolvents with different viscosity were chosen to investigate the self-assembly process of XBPO crystals from the perspective of molecular diffusion.It was found that the polymorphs and habits of crystals were well controlled.And then three new isomorphic solvates were obtained and crystal structures of these solvates were analyzed.At last,the molecular diffusion effect on the self-assembly of crystals was elucidated.