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Conjugated polymers (CPs), characterized by rigid conjugation backbones and flexible peripheral side chains, hold significant promise in various organic optoelectronic applications. In this study, we employ coarse‐grained molecular dynamics (CG‐MD) simulations to investigate the intricate interplay of solvent quality, temperature, and chain architecture (e.g., side‐chain length and molecular mass) on the conformational behaviors of CPs in dilute solutions. Our research uncovers distinctive conformational behaviors under varying solvent conditions, highlighting the versatile nature of polymer chains, which can adopt extended configurations in good solvents and transition to aggregated states in poor solvents. Additionally, the mass scaling exponent υ, a robust structural descriptor, consistently described CPs behavior across diverse architectures and solvent conditions. Furthermore, our study shows that a CP with longer side‐chain exhibits improved solubility, which is further confirmed by experimental observations. Moreover, our analysis of the shape descriptor κ2 provided valuable insights into the symmetry and dimensionality of CPs under varying solvent conditions. These findings offer a comprehensive understanding of conformational behaviors of CPs in dilute solution, which are helpful in guiding the conformational design of polymer for specific applications. [ABSTRACT FROM AUTHOR]

Understanding the complex structural behaviors of crumpled graphene at a fundamental level is of critical importance in various engineering and technological applications. Here, we present a coarse-grained molecular dynamics (CG-MD) study for investigating structural behaviors of graphene sheets having varying sizes (or masses) during the crumpling process. The simulation results reveal that larger size graphene sheets at the initial two-dimension (2D) state tends to become more self-adhering and self-folding upon crumpling compared to the smaller ones, before forming a sphere-like highly crumpled structure. The fractal dimension of the crumpled graphene sheets, i.e. , a measure of packing efficiency, is predicted to be D = 2.395 from our CG modeling, which is largely consistent with previous measurements. Remarkably, the size-dependence of various structural properties of the crumpled graphene sheets, including radius of gyration, hydrodynamic radius, and viscosity radius, can be quantitively described by the power-law scaling relationships during the crumpling process. By systematically evaluating shape descriptors, it is found that the overall crumpling behaviors of graphene sheets can be characterized by three different regimes (i.e. , less, intermediate, and highly crumpled states), which are associated with edge-bending, self-adhesion, and further compression mechanisms, respectively. Our study provides fundamental insights into the size-dependent structural behavior of graphene sheets under crumpling, which is crucial to develop the structure-property relationships towards designing and engineering crumpled matter. Image 1 [ABSTRACT FROM AUTHOR]

A theoretical analysis model of the dynamic properties of a 2-2 cement-based piezoelectric composite under impact load and its definite problems are presented based on the theory of piezo-elasticity in this article. Then, the theoretical solutions are obtained according to the Duhamel integral and variable separation method. The numerical simulations of the composite are presented by utilizing the transient step load, the transient haversine wave load, and transient isosceles triangle load, respectively, and compared with theoretical solutions, Zhang's results, and Li's results. It is found that the theoretical solutions have excellent agreement with the numerical simulations and Zhang's results and Li's results. In addition, the influences of piezoelectric parameters and thickness on the responses of the dynamic properties are discussed. The conclusion in this article could benefit the design and fabrication of 2-2 cement-based piezoelectric composites in engineering practice. [ABSTRACT FROM AUTHOR]