Miscibility of polylactide (PLA) and polyhydroxybutyrate (PHB) is studied by the microsecond atomistic molecular dynamics (MD) simulations for first time. The model simulation protocol were confirmed through comparison glass transition temperature (Tg) with experimental data. It was established that PLA PHB are miscible on basis Flory–Huggins theory. Analysis mobilities subchains revealed blends have two transitions to a glassy state at length scale few Kuhn segments, which in line...

Paraffin-based composites represent a promising class of materials with numerous practical applications such as e.g. heat storage. Computer modeling these complex multicomponent systems requires proper theoretical description both the n-alkane matrix and non-alkane filler molecules. The latter can be modeled use state-of-the-art general-purpose force field GAFF, CHARMM, OPLS-AA GROMOS, while paraffin is traditionally described in frame relatively old, alkane-specific fields (TraPPE, NERD,...

Abstract Polymer bio‐nanocomposites are widely used nowadays in various applications. One of the most promising polymers for producing such materials is poly(lactic acid) ( PLA ) filled with cellulose nanocrystals CNCs ). To increase compatibility hydrophobic and hydrophilic cellulose, surface latter can be chemically modified. Among modifications, grafting lactic acid oligomers OLAs special interest. In this paper, first all‐atom molecular dynamics simulation nanocomposites surface‐grafted...

The conventional definition of asphaltenes is based on their solubility in toluene and insolubility heptane. We have utilized this to study the influence partial charge parametrization aggregation behavior using classical atomistic molecular dynamics simulations performed microsecond time scale. Under consideration here are toluene- heptane-based systems with different charges parametrized general AMBER force field (GAFF). Systems standard GAFF calculated by AM1-BCC HF/6-31G*(RESP) methods...

The structural properties of polymer nanocomposites based on thermoplastic polyimides filled with surface-modified carbon nanotubes (CNT) have been studied by means fully-atomistic molecular-dynamics simulations.

We present results from all-atom molecular dynamics simulations for the structural properties of oligomeric lactic acid chains (OLA) grafted to surface cellulose nanocrystals (CNCs) and immersed in melt polylactic (PLA). Earlier, we have found that distribution free ends OLA molecules is bimodal [Glova et al., Polym. Int., 2016, 65(8), 892]. The cannot be explained within standard picture uncharged polymer brushes exposed a chemically identical polymer. Although are uncharged, they partial...

ABSTRACT A mesoscopic model of poly(lactic acid) is developed where the polymer represented as an A‐graft‐B chain with monomer units consisting two covalently connected beads. coarse‐graining algorithm proposed to convert atomistic PLA into a coarse‐grained one. The based on simulations oligolactides take account terminal groups correctly. It was used for polylactide. Gyration radii and end distances chains well density melt are shown be in good agreement those obtained from simulations....

The structure of a grafted layer lactide chains in the “dry brush” regime immersed melt chemically similar polymer was examined while varying graft lengths. To this end, microsecond atomistic molecular dynamics simulations were performed. Almost no influence length on fraction backfolded to grafting surface found. However, structural ordering unexpectedly observed system when close approximately 10 Kuhn segments. This grafts is characterized by formation helical fragments whose good...

A molecular-level insight into phase transformations is in great demand for many molecular systems. It can be gained through computer simulations which cooling applied to a system at constant rate. However, the impact of rate on crystallization process largely unknown. To this end, here we performed atomic-scale dynamics organic phase-change materials (paraffins), was varied over four orders magnitude. Our computational results clearly show that certain threshold (1.2 × 1011 K/min) values...

We put forward chemically modified asphaltenes, polycyclic aromatic byproducts of deep oil refining, for use as novel low-cost acceptor materials bulk heterojunction (BHJ) solar cells. The electronic properties asphaltenes with varying chemical structures are studied by density functional theory (DFT), while the morphology DFT-selected carboxyl-containing mixed poly(3-hexylthiophene) (P3HT) a model polymer-donor is investigated means all-atom molecular dynamics (MD) simulations. DFT...

We use atomistic molecular dynamics simulations to investigate the structure of oligohydroxybutyrate (OHB) and oligolactide (OLA) chains grafted onto cellulose nanocrystals (CNCs) in melts polyhydroxybutyrate polylactide chains, respectively. observed that, contrary established theory for neutral more flexible OHB grafts extend further from CNC surface, whereas stiffer OLA ones tend fold back toward surface by forming hairpin-like structures. Both have dipoles but are charge-neutral. To...

Asphaltenes represent a novel class of carbon nanofillers that are potential interest for many applications, including polymer nanocomposites, solar cells, and domestic heat storage devices. In this work, we developed realistic coarse-grained Martini model was refined against the thermodynamic data extracted from atomistic simulations. This allowed us to explore aggregation behavior thousands asphaltene molecules in liquid paraffin on microsecond time scale. Our computational findings show...

Adding carbon nanoparticles into organic phase change materials (PCMs) such as paraffin is a common way to enhance their thermal conductivity and improve the efficiency of heat storage devices. However, sedimentation stability blends can be low due aggregation aromatic in aliphatic environment. In this paper, we explore whether important issue resolved by introduction polymer agent poly(3-hexylthiophene) (P3HT) paraffin-nanoparticle blends: P3HT could ensure compatibility with chains. We...

Further development and commercialization of bulk heterojunction (BHJ) solar cells require the search for novel low-cost materials. The present study addresses relations between asphaltenes' chemical structure morphology poly(3-hexylthiohene) (P3HT)/asphaltene blends as potential materials design BHJ cells. By means all-atom molecular dynamics simulations, formation heterophase is observed P3HT-based with carboxyl-containing asphaltenes, well aggregation asphaltenes into highly ordered...

We aim to resolve the question of which grafted chains architecture (linear or branched) should be used for modification surface cellulose nanoparticles practically valuable polylactide-based nanocomposites.

Recent experiments and atomistic computer simulations have shown that asphaltene byproducts of oil refineries can serve as thermal conductivity enhancers for organic phase-change materials such paraffin therefore the potential to improve performance paraffin-based heat storage devices. In this work, we explore how size polycyclic aromatic cores asphaltenes affects properties paraffin-asphaltene systems by means molecular dynamics simulations. We show increasing core from 7-8 rings ∼20...

Machine learning methods provide an advanced means for understanding inherent patterns within large and complex datasets. Here, we employ the principal component analysis (PCA) diffusion map (DM) techniques to evaluate glass transition temperature (Tg) from low-dimensional representations of all-atom molecular dynamic simulations polylactide (PLA) poly(3-hydroxybutyrate) (PHB). Four descriptors were considered: radial distribution functions (RDFs), mean square displacements (MSDs), relative...