Pulsed-laser polymerization (PLP) in conjunction with polymer analysis by size-exclusion chromatography (SEC) is the IUPAC-recommended method for measuring propagation rate coefficients, *k*_{p}, of radical polymerization. Pulse repetition rate, *v*_{rep}, and photoinitiator concentration need to be adjusted to the termination rate of the monomer, preferably via the quantity *β*, the fraction of radicals terminating prior to applying the successive laser pulse. By PREDICI simulation, the prerequisites for successful PLP-SEC work are demonstrated. Slow termination, as with fully ionized monomers, is specifically addressed. Both very high and very low *v*_{rep} are not suitable for accurate *k*_{p} measurements.

**The PLP-SEC method runs into difficulties with radical termination being** too fast or too slow and in case of significant chain transfer and SEC broadening. The suitable selection of pulse repetition rate and photoinitiator concentration is emphasized for slow termination as with ionized monomers.

Five models are discussed giving the equilibrium constant for the catenation of two ring oligomers as a function of their Effective Molarity (EM), the physico-chemical parameter expressing the ease of cyclization of a chain. The first three models (A–C) are derived from the revision of previous theories of catenation, that neglect excluded volume effects. A fourth model (D) is obtained from the results of Monte Carlo simulations by Deguchi and co, that can also account for excluded volume effects. Finally, a fifth model (E) is introduced which has the same functional form of models A, B, D, but is parameterized using the available experimental catenation constant.

**On the basis of theories and simulations, the authors propose five models** giving the equilibrium constant *K _{ij}* for the catenation of two ring oligomers, C

The orientation of a three-layered silicate particle in uncompatibilized and compatibilized polymer melts is studied under shear flows utilizing dissipative particle dynamics (DPD). Based on trajectories, pair distribution functions are calculated in orthogonal planes. Regardless of the applied flow direction, it is shown that the layers rearrange themselves so that their surfaces would be normal to the velocity gradient direction. The maximum shear stress values fall in numerical uncertainties in uncompatibilized systems while they show a characteristic overshoot in compatibilized counterparts. This overshoot is shown to be a result of (i) the large interfaces between the silicate layers and the matrix due to the exfoliation, and (ii) the increased energy dissipation due to friction at the interface.

**The orientation of a three-layered silicate particle in uncompatibilized** and compatibilized polymer melts is studied under shear flows utilizing dissipative particle dynamics. It is shown that the layers rearrange themselves so that their surfaces would be normal to the velocity gradient direction. The orientation process is found to be more stable in compatibilized systems even at low shear-rates.

This study focuses on the estimation and validation of some interaction parameters of the Consistent Valence Force-Field (CVFF), which are required for the calculation of thermodynamic and transport properties of oxaliplatin (a colorectal anticancer drug) in poly(lactic-co-glycolic) acids (PLGAs) matrices. Our methodology to validate the parameters for PLGAs consisted on calculation of glass transition temperature and correlations between structural properties as: fractional free volume, polymer density, and cohesive energy density using Molecular dynamic simulations. For the oxaliplatin, metal-dependent and independent interaction parameters were included into CVFF and validated with an ab-initio method (RHF/LanL2DZ). The results achieved in the present work showed that the CVFF has been wellparameterized.

**Drug delivery systems (DDS) based on poly(lactic- co-glycolic acid) nanoparticles including platinum** complexes as oxaliplatin have been recommended for the enhancement of the efficiency in colorectal cancer treatment. The influence of different factors affecting the delivering rates of oxaliplatin in this type of DDS can be analyzed through Molecular Dynamic Simulations with the adaptation of existent force-fields for organic molecules.

Using self-consistent field (SCF) theory, we studied the self-assembly characteristics of polyurethane pre-polymer dispersions in aqueous solutions. With a molecularly detailed model implementing the Scheutjens–Fleer discretization scheme, it is shown how the stability, equilibrium size, and internal structure of the (swollen) micelles in polyurethane (PU) dispersions depend on the chemical structure and the molecular composition of the charged pre-polymer mixtures. The stability region of these micelles is found to increase when acid groups become deprotonated and when the ionic strength is lowered. Insight into the physical–chemical behavior of PU pre-polymer dispersions is important for the subsequent process of film formation from the PU dispersions for the final coating properties.

**Using self-consistent field (SCF) theory with a molecularly detailed model,** the authors study the self-assembly of polyurethane pre-polymer dispersions in aqueous solutions. Insight into the physical–chemical behavior of PU pre-polymer dispersions is obtained. Details like radial volume fraction distribution of six representative PU pre-polymers and water on a single swollen micelle are shown in this paper.

A dynamic Monte Carlo simulation is performed to investigate the dynamical heterogeneity during cooling toward the glass transition temperature (*T*_{g}). By tracking the evolution of the probability of segment movement (PSM), it is found that the ring polymer exhibits higher *T*_{g} than that of the linear polymer. The distributions of the mean square displacements (MSDs) of segments for the two kinds of polymers indicate the presence of heterogeneous dynamics upon approaching *T*_{g}. Compared with the linear chains, the ring chains exhibit weaker dynamical heterogeneity. The relatively weak dynamical heterogeneity in the ring chains is mainly caused by the mobility difference between the gauche- and trans-conformations. The observation on the local domains of blocked segments (LDBS) demonstrates that end segments with high mobility hinder the growth of LDBS, and thus enhance the dynamical heterogeneity.

**Ring polymer has larger local domains of blocked segments,** and thus narrower distributions of segmental mobility or weaker dynamical heterogeneity. Linear polymer has end segments with high mobility, which hindered the growth of local domains of blocked segments, and therefore wider distributions of segmental mobility, namely, stronger dynamical heterogeneity.

A mathematical model for describing the bulk free-radical polymerization of methyl-methacrylate was developed. This model includes a novel methodology for describing the diffusive step of the kinetic rate coefficients, which is based on geometric considerations and application of the Einstein diffusion Equation. The effect of polymer content and temperature on the *R*_{p} behavior is discussed in terms of the evolution of the interdependent parameters defining the *R*_{p}. The applicability of Smoluchowski equation and the importance of the translational diffusion of short radicals in the rate of termination reaction are questioned in this context. Similitudes and differences between the model results and experimental data are discussed including minima in the *R*_{p} curves at low conversions.

**The proposed model includes a novel methodology** for describing the diffusive step of the kinetic rate coefficients, which is based on geometric considerations and application of the Einstein diffusion equation instead of the Smoluchowski equation whose applicability is questioned in this context. An explanation for the rate of polymerization behavior and the onset of auto-acceleration effect is proposed.

**Cover:** Microelectronic manufacturing with block polymers is rapidly approaching commercialization. Highly controllable, uniform, and inexpensive nano-lithographic templates can be created, and the pattern from the selfassembled thin film can be transferred to the underlying substrate by reactive ion etching, creating morphologies with long-range order. Equilibrium morphologies of linear ABC triblock polymer melts both in bulk and under confinement are investigated. Specifically, the surface interaction and film thickness for highly sought-after perpendicular lamellae are delineated. Unstable and metastable morphologies are also identified and discussed. Further details can be found in the article by M. Mohagheghi and B. Khomami* on page 556.

Modification of inorganic particles with organic polymer layers leads to well defined hybrid nanoparticles with tunable properties. Studies of such systems rely on the investigation of polymers near to or attached at a surface. In the present investigation, size, shape, and orientation are investigated as functions of the distance of the center of gravity of linear and star-branched polymers from the surface by use of Monte Carlo methods for neutral and attractive surfaces in good and moderate solvents. To quantify the strength of interaction, a parameter “excluded distance” is introduced. It vanishes if repulsive interaction due to the excluded volume effect and attractive ones compensate, which is roughly the case for surface–polymer interactions similar to polymer–polymer interactions in theta solvents.

**The paper deals with the interaction of unconstraint** as well as anchored single chains and stars with energetically neutral and attractive walls representing surfaces of nanoparticles. Although simulations are based on lattice models, lattice independent results of general validity are obtained by extrapolation to infinite chain-length, at least for neutral surfaces. A new method to determine some sort of critical adsorption point is introduced.

Three dimensional self-consistent field theoretic simulations have been performed to determine the equilibrium morphologies formed by linear ABC triblock polymer melts confined between two parallel plates that favor the middle block. Our primary goal is to elucidate the conditions under which the perpendicular lamella is stabilized, since this morphology plays a central role in many nanotechnology applications. Key factors, namely, the chain architecture, surface energy and the mismatch between the film thickness d and the bulk lamella period, L_{0}, determine the final morphologies, e.g., perpendicular and parallel lamella, perforated lamella and wet substrate with parallel cylinders in the core, have been identified. Overall, our findings are fully consistent with the results of limited experimental studies focused on morphology development in thin films of triblock polymer melts. Finally, we have clearly demonstrated that ABC triblocks hold technological advantages over diblocks for nano-lithographic fabrications.

**Morphological transition of symmetric linear ABC triblock terpolymer** melt as a function of surface interaction and film thickness, d. In the presence of strong surface interaction, a wetting layer adjacent to the walls exists and in the center of the film, stable and metastable morphologies including C_{||}, L⊥ and PL are observed.

Reactivity ratio estimation was carried out in various nonlinear models using Markov Chain Monte Carlo (MCMC) technique and an error-in-variables (EVM) regression model. The implementation steps for three different polymerization case studies are discussed in detail and the results from this work are compared to previously used approximation methods. Approximation techniques that rely on linear regression theory are shown to produce inaccurate joint confidence regions (JCRs). Therefore, in this paper, we explore MCMC techniques that can be used to produce JCRs with correct shape and probability content. In addition, the paper illustrates how an EVM model can be used in tackling any type of regression problem, including multi-response problems.

**Markov Chain Monte Carlo methods are applied in the estimation of reactivity** ratios in various nonlinear models. An error-in-variables approach is used and the analysis shows that application of MCMC and EVM methods produce the most reliable results in nonlinear regression.

The structure and thermodynamic aspects of symmetric poly(styrene-*block*-acrylicacid)(PS-*b*-PAA) copolymer micelle in salt-free aqueous solution as a function of ionization (*f*) of PAA was probed by molecular dynamics simulations. Quantitative comparison of micelle radius shows that the GROMOS parameter set gives the best agreement with experiment. As *f* increases, Micelle size increases, attains spherical shape, PS surface area increases, and PAA water hydrogen-bonds increases. Pair correlation functions and solvation enthalpy show that PS interactions are insensitive to *f*. Density profiles and solvation enthalpy of PAA–Na^{+}, water–Na^{+} pairs confirm the micelle being in the “osmotic regime” experiments.

**The polystyrene- block-polyacrylic acid (PS-b-PAA) micelle** in aqueous solution shows the linear increase in micelle radius and constant PS core size as a function of ionization of PAA (

Technology for designing functional polymers needs to incorporate biomimetic structures for a new functionality. A simulation method, referred to as “molecular-cluster-assembly,” is used to design aggregate structures comprised of oligomers in a bottom-up manner and predict the capability of molecular capture. Acrylic acid oligomer forms an arched and syndiotactic structure with minimum energy. In accordance with the degree of aggregation, arched oligomers form a constricted structure with a unique channel width. The aggregate structures capture ethylene carbonates (ECs) inside the constricted channel and produce attractive energy between the ECs in host-guest complexes. The optimum numbers of ECs stably captured are determined when the binding energy at which the guests are captured at the outside wall of the channel exceeds the attractive energy between the guests in the constricted channel.

**Aggregate structures of acrylic acid oligomers** and the capability of capturing ethylene carbonates (ECs) are analyzed by molecular-cluster-assembly method. A hexamer comprised of arched oligomers captures two ECs in series inside the middle of a constricted channel. Methylene and carbonyl groups of the two ECs form hydrogen bondings and attractive interaction between them.