Aqueous solutions containing a mixture of polyethylene glycol (PEG) and dextran homopolymers form an aqueous two-phase system which can be emulsified to give water-in-water emulsion. We show how these emulsions stabilized using triblock polymers poly[poly(ethylene glycol) methyl ether methacrylate] (PEGMA), poly (n-butyl methacrylate) (BuMA), poly[2-(dimethylamino) ethyl (DMAEMA) blocks general structure Pp-Bb-Dd, in the middle BuMA block is hydrophobic. Low-energy input stirring mixtures...

Spherical colloidal particles generally self-assemble into hexagonal lattices in two dimensions. However, more complex, non-hexagonal phases have been predicted theoretically for isotropic with a soft repulsive shoulder but not experimentally realized. We study the phase behavior of microspheres presence poly(N-isopropylacrylamide) (PNiPAm) microgels at air/water interface. observe complex diagram, including chain and square arrangements, which exclusively form microgels. Our experimental...

We study the structure of binary monolayers large (3 μm diameter) very hydrophobic (A) and hydrophilic (B) or small (1 (C) silica particles at an octane-water interface. By tuning composition packing geometry mixed monolayer, we find that a rich variety two-dimensional hexagonal superlattices A/B A/C clusters are formed, stabilized by short-ranged electrostatic induced dipole interactions. The cluster structures obtained in excellent agreement with zero temperature calculations, indicating...

We study the structure of mixed monolayers large ($3\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ diameter) and small ($1\text{ very hydrophobic silica particles at an octane-water interface as a function number fraction $\ensuremath{\xi}$. find that rich variety two-dimensional hexagonal super-lattices ($A$) ($B$) can be obtained in this system due to strong long-range electrostatic repulsions through nonpolar octane phase. The structures for different compositions are good agreement with...

Significance The spontaneous self-organization of matter is ubiquitous in nature and an attractive technological approach to create defined nanostructured materials from the bottom-up. Spherical colloidal particles are among most widely used building blocks, but their self-assembly limited hexagonal symmetries as densest sphere packing. Here, we demonstrate that this limitation structural versatility can be overcome using soft core–shell self-assembling at a liquid interface. propensity...

We discuss various mechanisms for viscous dissipation m the linear response to oscillatory shear of incompressible foams (such as biliquid or dense emulsions). These include flow liquid in films and plateau borders; intrinsic viscosity surfactant layers; diffusion resistance Marangoni-type marginal regeneration are considered transport surfactant. predict (on basis typical parameters bihquid foams) that zero is usually dominated by dilational monolayers, though other forms may be important...

Using a molecular dynamics and mean field theory approach which explicitly accounts for free ions, we study the conformation of polyelectrolyte dendrimers different generation numbers, spacer lengths, charge distributions ionic strengths. We find that, due to local neutrality, electrostatic interactions are strongly screened under all conditions studied (including salt conditions). This leads cores being filled very weak dependence dendrimer conformations on strength. These results contrary...

Hard-core/soft shell (HCSS) particles have been shown to self-assemble into a remarkably rich variety of structures under compression due the simple interplay between hard-core and soft-shoulder length scales in their interactions. Most studies this area model soft interaction as square shoulder potential. Although appealing from theoretical point view, potential is physically unrealistic because there no repulsive force regime, unlike experimental HCSS systems. To make more realistic, here...

The unique behavior of colloids at liquid interfaces provides exciting opportunities for engineering the assembly colloidal particles into functional materials. deformable nature fluid-fluid means that we can use interfacial curvature, in addition to particle properties, direct self-assembly. To this end, a finite element method (Surface Evolver) study self-assembly rod-shaped adsorbed simple curved interface formed by sessile drop with cylindrical geometry. Specifically, single and multiple...

We present a microscopic theory for the interfacial rheology of fluid–fluid interface with adsorbed surfactant and calculate effect this on surface light scattering from interface. model head tail groups as polymer chains, description that becomes increasingly accurate large molecular weight surfactants, i.e., polymeric surfactants. Assuming high concentrations so we have double-sided brush monolayer, derive scaling expressions viscoelastic constants using Alexander–deGennes model. Our...

We study both experimentally and theoretically the self-assembly of binary polycaprolactone–polyethylene oxide (PCL–PEO) block copolymers in dilute solution, where is triggered by changing solvent from common good THF to selective water, two species on their own water form vesicles spherical micelles respectively. find that inter-micellar exchange these extremely slow so resultant self-assembled structures are local but not global equilibrium (i.e., they non-ergodic). This opens up...

Spherical colloidal particles typically self-assemble into hexagonal lattices when adsorbed at liquid interfaces. More complex assembly structures, including particle chains and phases with square symmetry, were theoretically predicted almost two decades ago for spherical interacting via a soft repulsive shoulder. Here, we demonstrate that such can be experimentally realized assembled the air/water interface in presence of molecular amphiphiles. We investigate interfacial behavior different...

We study the melt rheology and molecular weight distribution of four short chain branched hyperbranched polyesters with different weights containing monomers various alkyl lengths n (2 → 4; is number CH2 groups in chain). find that for all our samples obeys static scaling form n(M) ∼ M- τexp(−M/Mchar) where density polymers mass M, Mchar largest characteristic weight, τ polydispersity exponent. The values (either 1.35 or 1.55) are close to but not same as mean field value = 1.5, a...

We study via lattice Monte Carlo simulation and Flory theory the properties of g=1-6 dendrimers in variable solvent quality. For all generations studied, we find that radius gyration R(g) collapses significantly (factor 2) going from athermal to extreme poor conditions, indicating varying quality is an effective means controlling dendrimer size. also athermal, theta, scales with total number monomers roughly as approximately N(1/3). However, a more careful analysis shows theta solvents,...

We present a combined experimental and theoretical study on the role of copolymer architecture in self-assembly binary PEO–PCL mixtures water–THF show that altering chain geometry composition copolymers can control form self-assembled structures lead to formation novel aggregates. First, using transmission electron microscopy turbidity measurements, we mixture sphere-forming lamella-forming increasing molecular weight lamella-former at constant ratio its hydrophilic hydrophobic components...

The interaction between micron-sized charged colloidal particles at polar/non-polar liquid interfaces remains surprisingly poorly understood for a relatively simple physical chemistry system. By measuring the pair correlation function g(r) different densities of polystyrene decane-water interface, and using powerful predictor-corrector inversion scheme, effective pair-interaction potentials can be obtained up to fairly high densities, these reproduce experimental in forward simulations, so...

Spherical particles confined to liquid interfaces generally self-assemble into hexagonal patterns. It was theoretically predicted by Jagla two decades ago that such interacting via a soft repulsive potential are able form complex, anisotropic assembly phases. Depending on the shape and range of potential, minimum energy configurations include chains, rhomboid square We recently demonstrated deformable core-shell consisting hard silica core poly(N-isopropylacrylamide) shell adsorbed at an...

In recent years, self-assembly has emerged as a powerful tool for fabricating functional materials. Since is fundamentally determined by the particle interactions in system, if we can gain full control over these interactions, it would open door creating materials design. this paper, exploit capillary between colloidal particles at liquid interfaces to create two-dimensional (2D) where and be fully programmed using shape alone. Specifically, consider which are polygonal plates with...

We present a general theory for capillary waves and surface quasi-elastic light scattering an isotropic liquid interface with adsorbed surfactant. first examine the validity of three constitutive models interfaces in Newtonian regime, namely those Scriven, Goodrich, Kramer. Scriven's model contains interfacial constants: equilibrium tension γ, dilational viscosity ζs, shear ηs. Goodrich's Kramer's contain additional constant: transverse ηN, which is dissipative counterpart γ. find that while...

Well-defined ABC triblock copolymers based on two hydrophilic blocks, A and C, a hydrophobic block B are synthesized their self-assembly behavior is investigated. Interestingly, at the same solvent, concentration, pH, temperature, different shape micelles observed, spherical worm-like micelles, depending preparation method. Specifically, observed with bulk rehydration while both film rehydration.

The order−disorder transition temperature (TODT) of symmetric styrene−isoprene diblock copolymers (AB) and its hetero-four-arm star analog (A2B2) was measured using dynamic mechanical spectroscopy small-angle X-ray scattering (SAXS). Care taken to ensure that the arm molecular weights both AB A2B2 were matched. Contrary mean-field theory predictions, a significant difference in TODT, ΔTODT ≈ 30 °C, is found between two systems (the weight for styrene isoprene about 10 kg mol-1). We show this...

The frequency dependent viscoelastic properties and lamellar spacing of three symmetric styrene−isoprene (PS−PI) diblock copolymers are compared to those their hetero-four-arm star counterparts. PS PI arm molecular weights the linear samples 10, 20, 60 kg/mol, respectively. All six were unoriented had morphology for temperatures less than TODT, order−disorder temperature each weight. D at same was found scale with overall weight N according ∼ Nδ, δ ≈ 0.7 both stars. However, chains...

We present a configurational-biased lattice Monte Carlo scheme for simulating nonideal dendrimers that satisfies detailed balance. This corrects an important shortcoming in previous by Mansfield and Klushin: publication, we showed the Klushin did not obey balance, this led to surprisingly large errors radius of gyration Rg scattering form factor P(q) ideal dendrimers. In paper, have calculated gyration, factor, intramolecular density profile g = 1−8 self-avoiding find our results are...

We study theoretically the influence of an external magnetic field on orientation ellipsoidal particle adsorbed at a liquid interface. Using finite element program Surface Evolver, we calculate equilibrium meniscus shape around and its tilt angle with respect to undeformed interface θt when B is applied perpendicular find that as increase strength, increases critical Bc1 θc1, undergoes discontinuous transition 'perpendicular' (θt = 90°). Our results agree qualitatively simplified theory...