Interfacial Interaction Enhanced Rheological Behavior in PAM/CTAC/Salt Aqueous Solution-A Coarse-Grained Molecular Dynamics Study

SAXS-guided unbiased coarse-grained Monte Carlo simulation for identification of self-assembly nanostructures and dimensions

Recent studies have shown that solvated amphiphiles can form nanostructured self-assemblies called dynamic binary complexes (DBCs) in the presence of ions. Since the nanostructures of DBCs are directly related to their viscoelastic properties, it is important to understand how the nanostructures change under different solution conditions. However, it is challenging to obtain a three-dimensional molecular description of these nanostructures by utilizing conventional experimental characterization techniques or thermodynamic models. To this end, we combined the structural data from small angle X-ray scattering (SAXS) experiments and thermodynamic knowledge from coarse-grained Monte Carlo (CGMC) simulations to identify the detailed three-dimensional nanostructure of DBCs. Specifically, unbiased CGMC simulations are performed with SAXS-guided initial conditions, which aids us to sample accurate nanostructures in a computationally efficient fashion. As a result, an elliptical bilayer nanostructure is obtained as the most probable nanostructure of DBCs whose dimensions are validated by scanning electron microscope (SEM) images. Then, utilizing the obtained molecular model of DBCs, we could also explain the pH tunability of the system. Overall, our results from SAXS-guided unbiased CGMC simulations highlight that using potential energy combined with SAXS data, we can distinguish otherwise degenerate nanostructures resulting from the inherent ambiguity of SAXS patterns.

Fabricating Network-Link Acetamiprid-Loading Micelles Based on Dopamine-Functionalized Alginate and Alkyl Polyglucoside To Enhance Folia Deposition and Retention

The development of an eco-friendly nanopesticide formulation can alleviate the problems of low pesticide utilization and environmental pollution. However, the development of green nanopesticide carriers with ideal physical properties and specific bioavailability is still a challenging task at present. In this study, we propose a novel binary additive pesticide carrier system that is a functional polysaccharide-based polymer/surfactant (Alg-DA/APG) to improve the deposition and retention of pesticide droplets. The self-assembled micelle morphology of Alg-DA/APG and its effect on the apparent viscosity were investigated by transmission electron microscopy (TEM) and a Discovery HR-2 rotational rheometer. Surface tension was carried out to investigate the surface activity and critical micelle concentration (CMC) of Alg-DA/APG. The drop impacting experiments exhibited superior antisplash performance of Alg-DA/APG. Furthermore, a binary additive was used as the carrier material and loaded acetamiprid to prepare nanopesticide formulation Ace@Alg-DA/APG. The encapsulation efficiency (EE) and acetamiprid release behavior from Ace@Alg-DA/APG were also studied. Moreover, the dynamic contact angle (DCA) and retention experiment showed that the DCA and wetting radius at 600 s were, respectively, 6.8 ± 2.39° and 4.044 ± 0.0662 mm for the Ace@0.05 wt % Alg-DA/0.05 wt % APG on the banana foliage surface, and its retention rates on foliage surface were up to 74.80% after washing. The novel binary additive as a nanopesticide carrier has the potential to alleviate the problems of low pesticide utilization and environmental pollution in the future.

The Martini Model in Materials Science

The Martini model, a coarse-grained force field initially developed with biomolecular simulations in mind, has found an increasing number of applications in the field of soft materials science. The model's underlying building block principle does not pose restrictions on its application beyond biomolecular systems. Here, the main applications to date of the Martini model in materials science are highlighted, and a perspective for the future developments in this field is given, particularly in light of recent developments such as the new version of the model, Martini 3.