Mixing temperature optimization and modification mechanism of medical masks modified asphalt:Insights from computational chemistry  

作　　者：Heyang Ding Hongren Gong Lin Cong 

机构地区：[1]The Key Laboratory of Road and Traffic Engineering of the Ministry of Education,Tongji University,Shanghai 201804,China

出　　处：《International Journal of Transportation Science and Technology》2024年第4期177-193,共17页交通科学与技术(英文)

基　　金：supported by the National Natural Science Foundation of China(No.52178433 and 51878499).

摘　　要：Masks modified asphalt(MMA)provides a potential solution to pollution from discarded medical masks.Mixing temperature significantly affects storage stability and rheological performance of MMA.Traditional selection method overly relies on trial-and-error experiment,neglecting the convenience offered by computational chemistry.Furthermore,previous literature lacks precise elucidation of MMA’s physical modification mechanism,especially concerning the binding mode and energy composition.To address these issues,the optimal mixing temperature for MMA was recommended based on molecular dynamics(MD).The rationality of recommended temperature was validated through laboratory tests,simultaneously investigating the impact of heating time.Fluorescence microscopy and multi-band spectroscopy were employed to acquire the microstructure.Binding modes in MMA were determined using binding sites exploration,evaluating the energy composition of each binding mode through quantum chemistry(QC).The interaction mechanism was explained based on surface properties of isolated molecules.Results indicated that 170℃was the recommended optimal mixing temperature derived from mixing free energy and Flory-Huggins interaction parameter.The fluctuations in softening point difference(DTR&B)and separation ratio(R_(S))concurrently tended towards stability,thereby validating the reliability of recommended temperature.Moreover,even after 72 h heating,MMA prepared at recommended temperature remained within a reasonable range concerning DTR&B,RS,and microscopic structure.Perpendicular,parallel,toroidal,and spherical modes emerged in MMA.Perpendicular and parallel modes exhibited the highest binding energy,while circular mode demonstrated the lowest.Binding energy is primarily governed by van der Waals interaction,attributed to the dominance of dispersion term on MMA’s molecular surface.Besides,due to the presence of polycyclic aromatic hydrocarbons in asphalt molecules,electrostatic interaction contributed to specific molecular bindings.

关 键 词：Mixing temperature optimization Binding mode Energy-driven mechanism Energy decomposition Modified asphalt 

分 类 号：O64[理学—物理化学]