Gaussian Conformation Research Articles

Conformation of Network Strands in Polymer Gels.

Small angle neutron scattering was used to measure single chain radii of gyration of end-linked polymer gels before and after cross-linking to calculate the prestrain, which is the ratio of the average chain size in a cross-linked network to that of a free chain in solution. The prestrain increased from 1.06 ± 0.01 to 1.16 ± 0.02 as gel synthesis concentration decreased near the overlap concentration, indicating that the chains are slightly more stretched in the network than in solution. Dilute gels with higher loop fractions were found to be spatially homogeneous. Form factor and volumetric scaling analyses independently confirmed that elastic strands stretch by 2-23% from Gaussian conformations to create a space-spanning network, with increased stretching as network synthesis concentration decreases. Prestrain measurements reported here serve as a point of reference for network theories that rely on this parameter for the calculation of mechanical properties.

Temperature dependent single-chain structure of poly[3-(acrylamidopropyl-dimethyl-ammonium) propyl-1-sulfonate] via small-angle neutron scattering.

Responsive polyzwitterionic materials have become important for a range of applications such as environmental remediation and targeted drug delivery. Much is known about the macroscopic phase-behaviors of such materials, but how the smaller scale single-chain structures of polyzwitterions respond to external stimuli is not well understood, especially at temperatures close to their phase boundaries. Such chain conformation responses are important in directing larger-scale associative properties. Here, we study the temperature dependent single-chain structure of a model polysulfobetaine, poly[3-(acrylamidopropyl-dimethyl-ammonium) propyl-1-sulfonate], using small angle neutron scattering. In the absence of salt, we find that temperature has a large effect on solvent quality with a decreasing trend from good solvent conditions at 50 °C to poor solvent at 10 °C (a temperature just above the cloud point of 7.6 °C) and an estimated theta temperature of 39 °C. When 100 mM NaCl is present, the solvent quality is good with weak temperature dependence. Without salt present, the polymer chain appears to have a nearly Gaussian coil conformation and the backbone becomes slightly more rigid as the temperature is lowered to the cloud point as determined by the Debye-local rod model on a Kratky plot. The addition of salt has a notable effect on the intra-chain correlations where an increase in chain dimensions to a swollen coil conformation and an increase in chain rigidity is observed at 100 mM NaCl in D2O, however, with a negligible temperature dependence.

Characterization of the Local Volume Probed by the Side-Chain Ends of Poly(oligo(ethylene glycol) 1-Pyrenemethyl ether methacrylate) Bottle Brushes in Solution Using Pyrene Excimer Fluorescence

Four poly(oligo(ethylene glycol) 1-pyrenemethyl ether methacrylate) [P(PyEGyMA), with y = 3, 5, 8, and 12] samples were synthesized, where each side chain was terminated with a 1-pyrenemethoxy derivative. The efficiency of excimer formation between an excited-state pyrene and a ground-state pyrene was used to assess the conformation of the PyEGy side chains in these polymeric bottle brushes by conducting time-resolved fluorescence measurements in tetrahydrofuran (THF), N,N-dimethylformamide (DMF), dioxane, and dimethylsulfoxide (DMSO). These experiments took advantage of the dependency of the average rate constant ⟨k⟩ of pyrene excimer formation (PEF) on the local pyrene concentration [Py]loc experienced by an excited pyrene bound to the P(PyEGyMA) samples. [Py]loc could be estimated theoretically by assuming that the EGy side chains adopted a Gaussian conformation. Linear plots of ⟨k⟩/fdiff as a function of [Py]loc, where fdiff is the molar fraction of pyrenyl labels forming excimers by diffusion and was introduced to account for residual pyrene aggregation, were obtained in all four solvents, with slopes that depended on solvent viscosity and the probability of PEF upon the diffusive encounter between two pyrenyl labels. Solvent-induced differences in PEF efficiency could be accounted for by determining the bimolecular rate constant kdiff[inter] for intermolecular PEF with the model compound 1-pyrenemethyl diethylene glycol methyl ether in the four solvents. Except for DMSO, which was too polar and led to the segregation of the pyrenyl labels close to the polymethacrylate backbone, the data obtained for all P(PyEGyMA) samples in THF, DMF, and dioxane collapsed on a master line, similar to the one obtained earlier with a series of pyrene-labeled dendrons, when plotting ⟨k⟩/(fdiff × kdiff[inter])-vs-[Py]loc. The ⟨k⟩/(fdiff × kdiff[inter])-vs-[Py]loc master line confirmed the direct relationship that exists between the PEF efficiency and [Py]loc, a relationship that could be used to probe the conformation of highly branched macromolecules in solution.

Small-Angle Neutron Scattering Reveals the Structural Details of Thermosensitive Polymer-Grafted Cellulose Nanocrystal Suspensions.

Thanks to the use of small-angle neutron scattering (SANS), a detailed structural description of thermosensitive polymer-grafted cellulose nanocrystals (CNCs) was obtained and the behavior of aqueous suspensions of these derivatized biosourced particles upon temperature increase was revealed. Although literature data show that the surface grafting of thermosensitive polymers drastically enhances the colloidal properties of CNCs, direct space microscopic investigation techniques fail in providing sufficient structural information on these objects. In the case of CNCs decorated with temperature-sensitive polyetheramines following a peptide coupling reaction, a qualitative and quantitative analysis of SANS spectra shows that CNCs are homogeneously covered by a shell comprising polymer chains in a Gaussian conformation with a thickness equal to their radius of gyration in solution, thus revealing a mushroom regime. An increase of the temperature above the lower critical solution temperature (LCST) of the polyetheramine results in the formation of finite size bundles whose aggregation number depends on the particle concentration and suspension temperature deviation from the LCST. SANS analysis further reveals local changes at the CNC surface corresponding to a release of water molecules and a related denser polymer shell conformation. Noticeably, data show a full reversibility at all length scales when a sample was cooled down to below the LCST after being heated above it. Overall, the results obtained by SANS allow an in-depth structural investigation of derivatized CNCs, which is of high interest for the design of functional materials comprising these biosourced colloids.

Mobility of Polymer-Tethered Nanoparticles in Unentangled Polymer Melts.

A scaling theory is developed for the motion of a polymer-tethered nanoparticle (NP) in an unentangled polymer melt. We identify two types of scaling regimes depending on the NP diameter d and the size of a grafted polymer chain (tail) R tail . In one type of regimes, the tethered NP motion is dominated by the bare NP, as the friction coefficient of the tails is lower than that of the less mobile particle. The time dependence of the mean square displacement (MSD) of the tethered NP ⟨Δr 2(t)⟩ in the particle-dominated regime can be approximated by ⟨Δr 2(t)⟩ bare for the bare NP. In the other type of regimes, the tethered NP motion is dominated by the tails when the friction coefficient of the tails surpasses that of the particle at times longer than the crossover time τ ∗. In a tail-dominated regime, the MSD ⟨Δr 2(t)⟩ ≈ ⟨Δr 2(t)⟩ bare only for t < τ ∗. ⟨Δr 2(t)⟩ of a single-tail NP for t > τ ∗ is approximated as the MSD ⟨Δr 2(t)⟩ tail of monomers in a free tail, whereas ⟨Δr 2(t)⟩ of a multi-tail NP for t > τ ∗ is approximated as the MSD ⟨Δr 2(t)⟩ star of the branch point of a star polymer. The time dependence of ⟨Δr 2(t)⟩ in a tail-dominated regime exhibits two qualitatively different sub-diffusive regimes. The first sub-diffusive regime for t < τ ∗ arises from the dynamical coupling between the particle and the melt chains. The second sub-diffusive regime for t > τ ∗ occurs as the particle participates in the dynamics of the tails. For NPs with loosely grafted chains, there is a Gaussian brush region surrounding the NP, where the chain strands in Gaussian conformations undergo Rouse dynamics with no hydrodynamic coupling. The crossover time τ ∗ for loosely grafted multi-tail NPs in a tail-dominated regime decreases as the number of tails increases. For NPs with densely grafted chains, the tails are hydrodynamically coupled to each other. The hydrodynamic radii for the diffusion of densely grafted multi-tail NPs are approximated by the sum of the particle and tail sizes.

Importance of Compact Random Walks for the Rheology of Transient Networks.

Controlling the mechanical behavior of novel supramolecular materials is of the utmost importance and requires a fundamental understanding of the underlying physical processes. We present a multimethods approach to the dynamics of entangled transient polyisoprene networks. Small-angle neutron scattering (SANS) on randomly functionalized chains shows homogeneous supramolecular melts with Gaussian chain conformations. The H-bond lifetimes (dielectric α*-process) and the rheological response in terms of the loss modulus G″ differ by 2 orders of magnitude in time. Within the concept of a compact random walk (RW), where the random walker (urazole group acting as a sticker) undergoes multiple returns to its starting point and following the concept of theoretical proposed renormalized sticky bond lifetimes, we quantitatively solve this longstanding and unexplained large discrepancy: While the bond opening gives rise to the dielectric response, for rheological relaxation the association with a new partner is relevant. This takes place only after multiple returns to the original binding partner.

Internal Nanoparticle Structure of Temperature-Responsive Self-Assembled PNIPAM-b-PEG-b-PNIPAM Triblock Copolymers in Aqueous Solutions: NMR, SANS, and Light Scattering Studies

In this study, we report detailed information on the internal structure of PNIPAM-b-PEG-b-PNIPAM nanoparticles formed from self-assembly in aqueous solutions upon increase in temperature. NMR spectroscopy, light scattering, and small-angle neutron scattering (SANS) were used to monitor different stages of nanoparticle formation as a function of temperature, providing insight into the fundamental processes involved. The presence of PEG in a copolymer structure significantly affects the formation of nanoparticles, making their transition to occur over a broader temperature range. The crucial parameter that controls the transition is the ratio of PEG/PNIPAM. For pure PNIPAM, the transition is sharp; the higher the PEG/PNIPAM ratio results in a broader transition. This behavior is explained by different mechanisms of PNIPAM block incorporation during nanoparticle formation at different PEG/PNIPAM ratios. Contrast variation experiments using SANS show that the structure of nanoparticles above cloud point temperatures for PNIPAM-b-PEG-b-PNIPAM copolymers is drastically different from the structure of PNIPAM mesoglobules. In contrast with pure PNIPAM mesoglobules, where solidlike particles and chain network with a mesh size of 1-3 nm are present, nanoparticles formed from PNIPAM-b-PEG-b-PNIPAM copolymers have nonuniform structure with "frozen" areas interconnected by single chains in Gaussian conformation. SANS data with deuterated "invisible" PEG blocks imply that PEG is uniformly distributed inside of a nanoparticle. It is kinetically flexible PEG blocks which affect the nanoparticle formation by prevention of PNIPAM microphase separation.

Effect of polymer branching on degradation during inkjet printing

In this paper we demonstrate the potential of high molecular weight hyperbranched methacrylate polymers for inkjet printing. Using the Strathclyde method, a series of hyperbranched poly (methylmethacrylate) polymers of increasing branch density were prepared. All hyperbranched polymers show both a significantly greater maximum printable concentration compared to equivalent linear polymers with implications for faster print speed. Increasing chain branching above a critical value across the molecular weight distribution was found to result in suppression of molecular weight degradation. This resistance to molecular degradation is because the longest chain segment being much smaller, such that upon jetting the polymer rapidly retains its thermodynamically stable Gaussian coil conformation and the full force of the constrictional flow in the print head is not passed on to the polymer and degradation is supressed. We further go on to show using Electron Paramagnetic Resonance that degradation occurs via a free radical chain scission mechanism.

Concentrated Solutions of Single-Chain Nanoparticles: A Simple Model for Intrinsically Disordered Proteins under Crowding Conditions.

By means of large-scale computer simulations and small-angle neutron scattering (SANS), we investigate solutions of single-chain nanoparticles (SCNPs), covering the whole concentration range from infinite dilution to melt density. The analysis of the conformational properties of the SCNPs reveals that these synthetic nano-objects share basic ingredients with intrinsically disordered proteins (IDPs), as topological polydispersity, generally sparse conformations, and locally compact domains. We investigate the role of the architecture of the SCNPs in their collapse behavior under macromolecular crowding. Unlike in the case of linear macromolecules, which experience the usual transition from self-avoiding to Gaussian random-walk conformations, crowding leads to collapsed conformations of SCNPs resembling those of crumpled globules. This behavior is already found at volume fractions (about 30%) that are characteristic of crowding in cellular environments. The simulation results are confirmed by the SANS experiments. Our results for SCNPs--a model system free of specific interactions--propose a general scenario for the effect of steric crowding on IDPs: collapse from sparse conformations at high dilution to crumpled globular conformations in cell environments.

Structural Evolution of a Stimulus-Responsive Diblock Polypeptide Micelle by Temperature Tunable Compaction of its Core

With a perfectly defined primary structure, both in terms of monomer sequence and chain length, recombinant polypeptides obtained by protein engineering techniques allow the investigation of structure property relationships at a level of detail that is difficult to achieve with traditional synthetic polymers because of the precision with which their sequence can be defined. In the present work, we have studied the behavior and temperature-triggered self-assembly of a series of diblock recombinant elastin-like polypeptides (ELPs) with the goal of elucidating the mechanism of their self-assembly into micelles. Aqueous solutions of diblock ELPs were studied below and above their critical micellar temperature (CMT) by multiangle light scattering and small-angle neutron scattering techniques. Below the CMT, the radius of gyration of soluble ELP chains follows a power law as a function of molecular weight with an exponent value close to 0.5 that is characteristic of Gaussian coil conformations. As the temperature reaches the CMT, attractive interactions between the more hydrophobic block of diblock ELP chains leads to the self-assembly of monodisperse spherical micelles at thermodynamic equilibrium. Above the CMT, micelles expel water molecules from their core whose densification is evidenced by the monotonic increase in the light and neutron scattering intensities as a function of temperature. The behaviors of these different diblock ELPs in solution and as self-assembled nanoparticles above the CMT following universal experimental scaling laws make them analogous to synthetic amphiphilic diblock copolymers (star-like vs crew-cut micelle models). These studies also shed light on the important role of water in the thermal behavior of these thermally responsive self-assembling diblock polypeptides and suggest a new design parameter thermally triggered desolvation and densification of the core of micelles that can be fine-tuned at the sequence level to control the density of self-assembled polymer nanoparticles.

Conformation of the Poly(ethylene Glycol) Chains in DiPEGylated Hemoglobin Specifically Probed by SANS: Correlation with PEG Length and in Vivo Efficiency.

Cell-free hemoglobin (Hb)-based oxygen carriers have long been proposed as blood substitutes but their clinical use remains tricky due to problems of inefficiency and/or toxicity. Conjugation of Hb with the biocompatible polymer poly(ethylene glycol) (PEG) greatly improved their performance. However, physiological data suggested a polymer molecular weight (Mw) threshold of about 10 kDa, beyond which the grafting of two PEG chains no longer improves efficiency and nontoxicity of diPEG/Hb conjugates. We used small-angle neutron scattering and contrast variation, which are the only techniques able to probe separately the conformation of PEG chains and Hb protein within the complex, to investigate the role of PEG chain conformation in diPEGylated Hb conjugates as a function of the polymer Mw. We found out that the structure of Hb tetramer is not modified by the polymer grafting. Similarly, with a constant grafting of two chains per protein, there is no significant change of the Gaussian conformation between free and grafted PEG below ∼10 kDa, the complex being well described by the "dumbbell" model. However, beyond that threshold, the radius of gyration of grafted PEG is significantly smaller than that of the free polymer, showing a compaction of the PEG chains, either in the "dumbbell" model or in the "shroud" one. In the latter model, the polymer may be wrapped on the surface of the protein spreading a protective "shielding" effect over a larger fraction of the protein. Both proposed models are in good agreement with the physiological data reported in the literature.

Influence of the Solvent Quality on Ring Polymer Dimensions.

We present a systematic investigation of well-characterized, experimentally pure polystyrene (PS) rings with molar mass of 161 000 g/mol in dilute solutions. We measure the ring form factor at θ- and good-solvent conditions as well as in a polymeric solvent (linear PS of roughly comparable molar mass) by means of small-angle neutron scattering (SANS). Additional dynamic light scattering (DLS) measurements support the SANS data and help elucidate the role of solvent quality and solution preparation. The results indicate the increase of ring dimensions as the solvent quality improves. Furthermore, the experimental form factors in both θ-solvent and linear matrix behave as ideal rings and are fully superimposable. The nearly Gaussian conformations of rings in a melt of linear chains provide evidence of threading of linear chains through rings. The latter result has implications for the dynamics of ring-linear polymer mixtures.

Charging and uncharging a neutral polymer in solution: a small-angle neutron scattering investigation.

Aqueous formulations containing polymers and surfactants find several applications in pharmaceutics, coatings, inks, and home products. The association between polymers and surfactants contributes greatly to the function of these complex fluids, however, the effects of polar organic solvents, ubiquitous in formulations, remain mostly unexplored. We have analyzed small angle neutron scattering (SANS) data to determine the conformation of a "model" nonionic polymer, poly(ethylene oxide) (PEO), in aqueous solutions as affected by the presence of an ionic surfactant, sodium dodecyl sulfate (SDS), and subsequent addition of short-chain alcohol (ethanol or 2-propanol). PEO chains (MW = 90,000) are Gaussian in dilute aqueous solutions, but become polyelectrolyte-like upon the addition of 30 mM SDS, with about 6 SDS micelles bound to each PEO chain. Micelles associated with polymer are similar in structure and interactions to micelles that form in aqueous solutions in the absence of polymer. Addition of alcohol alters both the polymer and micelle structure and interactions, leads to detachment of micelles from the polymer, and the PEO chains regain their Gaussian conformation. 2-Propanol is more effective than ethanol in influencing the polymer conformation and the properties of SDS micelles in aqueous solutions, either in the presence or in the absence of PEO. This study contributes fundamental insights on polymer and surfactant organization in solution, as well as new, quantitative information on systems that are widely used in practice.

Using Soft Potentials for the Simulation of Block Copolymer Morphologies

A simulation strategy for the creation of equilibrated nanostructured copolymer melt morphologies is proposed. Molecular dynamics simulations of bead‐spring chains with a soft pair potential are used for efficient modeling of phase separation, while preserving Gaussian chain statistics and chain conformations of an underlying microscopic model. In a second step, hard excluded volume interactions are reintroduced that match the copolymer segregation strength but only require reequilibration of local packing structure. We show that substantial computational gains can be achieved for equilibrating moderately entangled bead‐spring polymers. The resultant configurations can be used for further studies of structural and mechanical properties in melts or glasses.

Optimization of the solid-state fermentation and properties of a polysaccharide from Paecilomyces cicadae (Miquel) Samson and its antioxidant activities in vitro.

The culture conditions for the yield of a polysaccharide (PCPS) produced by Paecilomyces cicadae (Miquel) Samson on solid-state fermentation were investigated using response surface methodology (RSM). Plackett–Burman design (PBD) was applied to screen out significant factors, followed by the paths of steepest ascent to move to the nearest region of maximum response. Then Box-Behnken design (BBD) was conducted to optimize the final levels of the culture conditions. After analyzing the regression equation and the response surface contour plots, relative humidity 56.07%, inoculum 13.51 mL/100 g and temperature 27.09°C were found to be the optimal key parameters for PCPS production. The maximum predicted yield of PCPS was 10.76 mg/g under the optimized conditions. The resulting PCPS (FPCPS) generated at optimal conditions was purified by chromatography column and found to be composed of mannose (43.2%), rhamnose (32.1%), xylose (14.5%) and arabinose (10.2%). Based on the size exclusion chromatography combined with multi-angle laser light scattering (SEC-MALLS) analysis, FPCPS adopted a Gaussian coil conformation in 0.1 M NaNO3 solution with 3.75×106 g/mol of the weight-average molar mass (Mw) and 41.1 nm of the root-mean square radius (Rg2)z 1/2. Furthermore, both of the polysaccharides were revealed to have strong antioxidant activities by evaluating in DPPH radical, superoxide radicals and hydroxyl radical assay. These data suggest the polysaccharides of Paecilomyces cicadae (Miquel) Samson produced by solid-state fermentation could be explored as potential natural antioxidants.

Molecular properties of hybrid macromolecular antioxidants: Dextran hydrophobically modified by sterically hindered phenols

The conformation properties of clinically relevant hybrid macromolecular antioxidants (dextran hydrophobically modified by sterically hindered phenols) in aqueous solution were characterized by a combination of dynamic light scattering (DLS), size exclusion chromatography (SEC), and small-angle neutron scattering (SANS). We were able to split and analyze separately two different types of polydispersity -polydispersity over molecular weights and the one over substitution degree. The properties of the hybrid macromolecules are determined by the number of hydrophobic antioxidants in a single molecule. An insertion of hydrophobic groups into a hydrophilic chain changes the conformation of a single conjugate macromolecule. We have established that with the increasing of a number of hydrophobic antioxidant groups, a conformational transition occurs where a single conjugate undergoes a transition from a Gaussian coil conformation to a more compact structure.

Synthesis and self‐assembly of amphiphilic macrocyclic block copolymer topologies

AbstractWe demonstrated the synthesis of miktoarm star block copolymers of AB, AB2, and A2B, in which block A consisted of linear poly(tert‐butyl acrylate) (PtBA) and block B consisted of cyclic polystyrene. These structures were produced using the atom transfer radical polymerization to make telechelic polymers that, after modification, were further coupled together by copper‐catalyzed “click” reactions with high coupling efficiency. Deprotection of PtBA to poly(acrylic acid) (PAA) afforded amphiphilic miktoarm structures that when micellized in water gave vesicle morphologies when the block length of PAA was 21 units. Increasing the PAA block length to 46 units produced spherical core‐shell micelles. AB2 miktoarm stars packed more densely into the core compared to its linear counterpart (i.e., a four times greater aggregation number with approximately the same hydrodynamic diameter), resulting in the PAA arms being more compressed in the corona and extending into the water phase beyond its normal Gaussian chain conformation. These results show that the cyclic structure attached to an amphiphilic block has a significant influence on increasing the aggregation number through a greater packing density. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.

Chain-Length Dependence of the Segmental Relaxation in Polymer Melts: Molecular Dynamics Simulation Studies on Poly(propylene oxide)

Performing molecular dynamics simulations for an all-atom force field, we study the segmental or, equivalently, α relaxation of poly(propylene oxide) chains consisting of N = 2−100 monomer units. In particular, we analyze the dependence of the α relaxation on molecular weight and temperature on the basis of incoherent intermediate scattering functions. For all studied chain lengths N, the temperature dependence is well described by a Vogel−Fulcher−Tammann behavior and time−temperature superposition is obeyed at sufficiently low temperatures T. When the molecular weight increases, time scale and stretching of the α relaxation smoothly increase until they saturate at N = 30−40, where the characteristic ratio reaches the limiting value C∞ and, hence, the chains start to show Gaussian conformation. The temperature-dependent α relaxation times collapse onto a master curve in a fragility plot, indicating that the high-temperature fragility of the model polymer is independent of the degree of polymerization. We ...

Structure and self-assembly properties of a new chitosan-based amphiphile.

A new chitosan-based amphiphile, octanoyl-chitosan-polyethylene glycol monomethyl ether (acylChitoMPEG), has been prepared using both hydrophobic octanoyl and hydrophilic polyethylene glycol monomethyl ether (MPEG) substitutions. The success of synthesis was confirmed by Fourier transform infrared (FT-IR) and (1)H NMR spectroscopy. The synthesized acylChitoMPEG exhibited good solubility in either aqueous solution or common organic solvents such as ethanol, acetone, and CHCl(3). The self-aggregation behavior of acylChitoMPEG in solutions was studied by a combination of pyrene fluorescence technique, dynamic light scattering, atomic force microscopy, and small-angle X-ray scattering (SAXS). The critical aggregation concentration (CAC) and hydrodynamic diameter were found to be 0.066 mg/mL and 24.4 nm, respectively. SAXS results suggested a coiled structure of the triple helical acylChitoMPEG backbone with the hydrophobic moieties hiding in the center of the backbone, and the hydrophilic MPEG chains surrounding the acylChitoMPEG backbone in a random Gaussian chain conformation. Cytotoxicity results showed that acylChitoMPEG exhibited negligible cytotoxicity even at concentrations as high as 1.0 mg/mL. All results implied that acylChitoMPEG has the potential to be used for biological or medical applications.

“Wet-to-Dry” Conformational Transition of Polymer Layers Grafted to Nanoparticles in Nanocomposite

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXT“Wet-to-Dry” Conformational Transition of Polymer Layers Grafted to Nanoparticles in NanocompositeChloé Chevigny†#, Jacques Jestin*†, Didier Gigmes‡, Ralf Schweins§, Emanuela Di-Cola∥, Florent Dalmas⊥, Denis Bertin‡, and François Boué†View Author Information† Laboratoire Léon Brillouin, CEA Saclay 91191 Gif-sur-Yvette Cedex, France‡ Laboratoire Chimie Provence, UMR 6264, CNRS et Universités d’Aix-Marseille 1,2 et 3, Site de St Jérôme, Av. Esc. Normandie-Niemen case 542, 13393 Marseille Cedex 20, France§ Institut Laue Langevin DS/LSS 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France∥ European Synchrotron Radiation Facility, 6 rue Jules Horowitz B.P. 220, 38043 Grenoble Cedex 9, France⊥ Institut de Chimie et des Matériaux Paris-Est, CNRS UMR 7182, 2-8 rue Henri Dunant 94320 Thiais, France*Corresponding author. E-mail: [email protected]#Present address: Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Sekr. TC 9, Strasse des 17. Juni 124, D-10623 Berlin.Cite this: Macromolecules 2010, 43, 11, 4833–4837Publication Date (Web):May 7, 2010Publication History Received19 April 2010Revised29 April 2010Published online7 May 2010Published inissue 8 June 2010https://doi.org/10.1021/ma100858hCopyright © 2010 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1500Altmetric-Citations67LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (4 MB) Get e-AlertsSUBJECTS:Nanocomposites,Nanoparticles,Particulate matter,Polymers,Silica Get e-Alerts