Shear-driven segregation kinetics in binary polymer blends: Insights from dissipative-particle-dynamics simulations.

This study investigates the phase separation kinetics of binary (AB) polymer blends under various shear conditions using dissipative particle dynamics simulations. The system, confined by two parallel walls, is subjected to different shear cases, including stationary and moving walls. The simulations explore critical and off-critical polymer compositions, analyzing morphological evolution, scaling behavior, domain growth, and structural anisotropy.

Stabilizing Pickering Emulsions with Polymer Brush-Modified Tricompartmental Anisotropic Particles: A Simulation and Experimental Study.

We study the stability of oil-in-water Pickering emulsions using tricompartmental brush-modified anisotropic particles (TBPs) through Dissipative Particle Dynamics (DPD) simulations. Our study examines how TBP functionality, including brush length, density, and surface modification, influences emulsion stability. We designed four distinct tricompartmental macroparticles (TPs), labeled TP-1 to TP-4, by grafting polymer brushes via surface-initiated atom transfer radical polymerization (ATRP).

Self-assembly kinetics of miktoarm star polymers in diverse solvent environments: insights from dissipative particle dynamics simulations.

We present the self-assembly kinetics of miktoarm star polymers (MSPs) with compositional and topological asymmetries in various solvents using three-dimensional dissipative particle dynamics simulations. Morphological evolution, analyzed radial distribution, spatial correlation functions, and domain growth exponents, reveals distinct structures driven by solvent-MSP interactions. Good solvents promote a mostly slow domain growth rate, resulting in a porous morphology, whereas poor solvents facilitate a faster growth rate and lead to denser and localized lamellar or cylindrical structures.

Segregation kinetics of miktoarm star polymers: A dissipative particle dynamics study.

We study the phase separation kinetics of miktoarm star polymer (MSP) melts/blends with diverse architectures using dissipative particle dynamics simulation. Our study focuses on symmetric and asymmetric miktoarm star polymer (SMSP/AMSP) mixtures based on arm composition and number. For a fixed MSP chain size, the characteristic microphase-separated domains initially show diffusive growth with a growth exponent ϕ∼1/3 for both melts that gradually crossover to saturation at late times.

Evolution Kinetics of Stabilizing Pickering Emulsion by Brush-Modified Janus Particles: DPD Simulation and Experimental Insights.

In the present study, we report the evolution of stabilizing Pickering emulsions using brush-modified Janus particles (JPs), utilizing the dissipative particle dynamics (DPD) simulation technique. Our results are subsequently corroborated with experimental findings. Each JP has one-half of the hydrophobic surface, with the other half embedded with hydrophilic polymer brushes grown via atom transfer radical polymerization (ATRP).

Architecture dependent transport behavior of iron (0) entrapped biodegradable polymeric particles for groundwater remediation.

Polylactic acid based spherical particles with three architectural variations (Isotropic (P1), Semi porous (P2), and Janus (P3)) were employed to encapsulate zero valent iron nanoparticles (ZVINPs), and their performance was extensively evaluated in our previous studies. However, little was known about their transportability through saturated porous media of varying grain size kept under varying ionic strength. In this particular study, we aimed to investigate the architectural effect of polymeric particles (P1-P3) on their mobility through the sand column of varying grain size in presence of mono, di, and tri-valent ions of varying concentrations (25-200 mM (millimoles)).

Growth kinetics and morphology characterization of binary polymeric fluid under random photo-illumination.

We present a comprehensive study using dissipative particle dynamics simulations to investigate phase separation kinetics (PSK) in three-dimensional (3d) polymeric fluids under random photo-illumination. We consider two scenarios: polymer blends with active radicals at one end of each immiscible chain and block copolymer (BCP) melts with photosensitive bonds linking incompatible blocks. The phase separation (PS) is induced by temperature quench of the initial homogeneously mixed system.

Effect of amphiphilic polymers on phase separating binary mixtures: A DPD simulation study.

We present the phase separation dynamics of a binary (AB), simple fluid (SF), and amphiphilic polymer (AP) mixture using dissipative particle dynamics simulation at d = 3. We study the effect of different AP topologies, including block copolymers, ring block copolymers (RCP), and miktoarm star polymers, on the evolution morphologies, dynamic scaling functions, and length scale of the AB mixture. Our results demonstrate that the presence of APs leads to significantly different evolution morphologies in SF.

Segregation of fluids with polymer additives at domain interfaces: a dissipative particle dynamics study.

This paper investigates the phase separation kinetics of ternary fluid mixtures composed of a polymeric component (C) and two simple fluids (A and B) using dissipative particle dynamics simulations with a system dimensionality of = 3. We model the affinities between the components to enable the settling of the polymeric component at the interface of fluids A and B. Thus, the system evolves to form polymer coated morphologies, enabling alteration of the fluids' interfacial properties.

Dissipative particle dynamics simulation study on ATRP-brush modification of variably shaped surfaces and biopolymer adsorption.

We present a dissipative particle dynamics (DPD) simulation study on the surface modification of initiator embedded microparticles (MPs) of different shapes atom transfer radical polymerization (ATRP) brush growth. The surface-initiated ATRP-brush growth leads to the formation of a more globular MP shape. We perform the comparative analysis of ATRP-brush growth on three different forms of particle surfaces: cup surface, spherical surface, and flat surface (rectangular/disk-shaped).

High Adsorption of α-Glucosidase on Polymer Brush-Modified Anisotropic Particles Acquired by Electrospraying-A Combined Experimental and Simulation Study.

In this particular contribution, we aim to immobilize a model enzyme such as α-glucosidase onto poly(DMAEMA) [poly(2-dimethyl amino ethyl methacrylate)] brush-modified anisotropic (cup- and disc-shaped) biocompatible polymeric particles. The anisotropic particles comprising a blend of PLA [poly(lactide)] and poly(MMA--BEMA) [poly((methyl methacrylate)--(2-(2-bromopropionyloxy) ethyl methacrylate)] were acquired by electrospraying, a scalable and convenient technique. We have also demonstrated the role of a swollen polymer brush grafted on the surface of cup-/disc-shaped particles via surface-initiated atom transfer radical polymerization in immobilizing an unprecedentedly high loading of enzyme [441 mg/g (cup)-589 mg/g (disc) of particles, 15-20 times higher than that of the literature-reported system] as compared to non-brush-modified particles.

Photo-induced bond breaking during phase separation kinetics of block copolymer melts: a dissipative particle dynamics study.

Using a dissipative particle dynamics (DPD) simulation method, we study the phase separation dynamics in block copolymer (BCP) melts in d = 3, subjected to external stimuli such as light. An initial homogeneous BCP melt is rapidly quenched to a temperature T < T, where T is the critical temperature. We then allow the system to undergo alternate light "on" and "off" cycles.

Role of a polymeric component in the phase separation of ternary fluid mixtures: a dissipative particle dynamics study.

We present the results from dissipative particle dynamics (DPD) simulations of phase separation dynamics in ternary (ABC) fluids mixture in d = 3 where components A and B represent the simple fluids, and component C represents a polymeric fluid. Here, we study the role of polymeric fluid (C) on domain morphology by varying composition ratio, polymer chain length, and polymer stiffness. We observe that the system under consideration lies in the same dynamical universality class as a simple ternary fluids mixture.

Designing polymer gels and composites that undergo bio-inspired phototactic reconfiguration and motion.

Inspired by the adaptive behavior of photo-responsive biological organisms, we develop analytical and computational models to design polymer gels and composites that can be dynamically reconfigured and driven to move with the application of light. We focus on gels formed from poly(N-isopropylacrylamide) and functionalized with spirobenzopyran (SP) chromophores, which become hydrophobic under blue light in acidic aqueous solution. Using our modeling approaches, we irradiate the gels through photomasks and demonstrate that the shapes of the samples can be reversibly and remotely 'remolded' by varying the apertures in the masks.

Effect of bond-disorder on the phase-separation kinetics of binary mixtures: A Monte Carlo simulation study.

We present Monte Carlo (MC) simulation studies of phase separation in binary (AB) mixtures with bond-disorder that is introduced in two different ways: (i) at randomly selected lattice sites and (ii) at regularly selected sites. The Ising model with spin exchange (Kawasaki) dynamics represents the segregation kinetics in conserved binary mixtures. We find that the dynamical scaling changes significantly by varying the number of disordered sites in the case where bond-disorder is introduced at the randomly selected sites.

Combining ATRP and FRP Gels: Soft Gluing of Polymeric Materials for the Fabrication of Stackable Gels.

Stackable gels comprised of layers of dissimilar polymers were synthesized by combining conventional free radical polymerization (FRP) and atom transfer radical polymerization (ATRP) using two approaches: (i) polymerization of a pre-gel solution containing a monomer and cross-linker introduced on top of a previously prepared gel, and (ii) simultaneous polymerization of two immiscible pre-gel solutions remaining in contact. All permutations of FRP and ATRP yielded single-piece, connected, amphiphilic gels regardless of the order of polymerization. Furthermore, multi-layer ATRP gels combining different polymers were synthesized with the FRP layer as a gluing agent.

Living Additive Manufacturing: Transformation of Parent Gels into Diversely Functionalized Daughter Gels Made Possible by Visible Light Photoredox Catalysis.

Light-initiated additive manufacturing techniques typically rely on layer-by-layer addition or continuous extraction of polymers formed via nonliving, free radical polymerization methods that render the final materials "dead" toward further monomer insertion; the polymer chains within the materials cannot be reactivated to induce chain extension. An alternative "living additive manufacturing" strategy would involve the use of photocontrolled living radical polymerization to spatiotemporally insert monomers into dormant "parent" materials to generate more complex and diversely functionalized "daughter" materials. Here, we demonstrate a proof-of-concept study of living additive manufacturing using end-linked polymer gels embedded with trithiocarbonate iniferters that can be activated by photoinduced single-electron transfer from an organic photoredox catalyst in solution.

Photo-regeneration of severed gel with iniferter-mediated photo-growth.

Using dissipative particle dynamics (DPD), we developed a computational approach to model the light-induced regeneration of a gel matrix when a significant portion of the material is severed. We considered photo-controlled radical polymerization (photo-CRP) within polymer networks with embedded iniferter groups: the "photo-growth" strategy. Absorption of light by the iniferter groups turns on the polymerization process, which inserts monomers and cross-linkers into the network strands.

Embedding flexible fibers into responsive gels to create composites with controllable dexterity.

Using computational modeling, we design a composite that encompasses a thermo-responsive gel and photo-responsive fibers that extend from the surface of the gel. By simulating the effect of light and heat on the sample, we isolate scenarios where cooperative interactions within the system allow the gel to actuate the "finger-like" motion of the embedded fibers. To achieve this distinctive behavior, we consider a gel formed from poly(N-isopropylacrylamide) (PNIPAAm), which shrinks when heated above the lower critical solution temperature (LCST).

Ordering Dynamics in Neuron Activity Pattern Model: An Insight to Brain Functionality.

We study the domain ordering kinetics in d = 2 ferromagnets which corresponds to populated neuron activities with both long-ranged interactions, V(r) ∼ r-n and short-ranged interactions. We present the results from comprehensive Monte Carlo (MC) simulations for the nonconserved Ising model with n ≥ 2, interaction range considering near and far neighbors. Our model results could represent the long-ranged neuron kinetics (n ≤ 4) in consistent with the same dynamical behaviour of short-ranged case (n ≥ 4) at far below and near criticality.

Phase separation in ternary fluid mixtures: a molecular dynamics study.

We present detailed results from molecular dynamics (MD) simulations of phase separation in ternary (ABC) fluid mixtures for d = 2 and d = 3 systems. Our MD simulations naturally incorporate hydrodynamic effects. The domain growth law is l(t) ∼ t(ϕ) with dynamic growth exponent ϕ.

Kinetics of phase separation in polymer mixtures: a molecular dynamics study.

We present detailed results from a molecular dynamics (MD) simulation of phase-separation kinetics in polymer mixtures. Our MD simulations naturally incorporate hydrodynamic effects. We find that polymeric phase separation (with dynamically symmetric components) is in the same universality class as segregation of simple fluids: the degree of polymerization only slows down the segregation kinetics.

Growth kinetics of nanoclusters in solution.

We study the growth kinetics of nanoclusters in solution. There are two generic factors that drive growth: (a) reactions that produce the nanomaterial; and (b) diffusion of the nanomaterial due to chemical-potential gradients. We model the growth kinetics of ZnO nanoparticles via coupled dynamical equations for the relevant order parameters.

Control of structure formation in phase-separating systems.

In this paper, we study the evolution of phase-separating binary mixtures which are subjected to alternate cooling and heating cycles. An initially homogeneous mixture is rapidly quenched to a temperature T(1)T(c).