Citation for published item:friddikD erron nd pongD ee tF nd tti¡ eD ilise pF hF nd viD eixun nd kodD wximilin F eF nd gourhyD plorene nd hompsonD ihrd vF @PHIVA 9flooming of smeti surftntGplstiizer lyers on spinEst poly@vinyl loholA (lmsF9D vngmuirFD QR @RAF ppF IRIHEIRIVF Further information on publisher's website: This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. The magnitude of this surface excess increased significantly in the presence of the plasticizer, and the surfactant was largely excluded from the PVA subphase. NR revealed smectic nanostructures for both SDS and glycerol components within this surface excess in plasticized films. This combined layer comprises surfactant lamellae, separated by interstitial glycerolrich layers, which is only formed in the plasticized films and persists throughout the surface excess. Atomic force microscopy micrographs of the film surfaces revealed platelike structures in the plasticized PVA, which were consistent with the rigid defects in the surfactant-rich lamellae. The formation of these structures arises from the synergistic surface segregation of SDS and glycerol, evidenced by surface tensiometry. Cloud point analysis of bulk samples indicates a transition at ∼55% water content, below which phase separation occurs in ternary films. This transition is likely to be necessary to form the thick wetting layer observed and therefore indicates that film components remain mobile beyond this point in the drying process. ■ INTRODUCTIONPoly(vinyl alcohol) (PVA) is a semicrystalline synthetic polymer that has been widely exploited for its ability to form high-quality optically transparent films. Characteristics such as degree of hydrolysis (DH) and degree of polymerization must be carefully controlled to provide optimal physical properties such as strength and solubility of PVA films. 1,2 For many industrial applications, pure PVA films are too brittle and inflexible; hence, plasticizers are introduced into the system. Glycerol has been shown to be a compatible plasticizer 3 and is utilized in many cases to improve film flexibility while retaining good levels of tensile and shear strength.The prediction of surfactant behavior in polymer films and the tendencies of small molecules to migrate and segregate remains a fundamental scientific challenge, which has...

Compatibility between oligomers and polymers was systematically assessed using differential scanning calorimetry (DSC) and was correlated with similarity in saturation and solubility parameter. These measurements enabled validation of detailed volume of mixing calculations using Statistical Association Fluid Theory (SAFT-γ Mie) and molecular dynamics (MD) simulations, which can be used to predict behaviour beyond the experimentally accessible conditions. These simulations confirmed that squalane is somewhat more compatible with poly(isoprene), "PI" than poly(butadiene), "PB", and further enabled prediction of the temperature dependence of compatibility. Surface and interfacial segregation of a series of deuterated oligomers was quantified in rubbery polymer films: PI, PB and hydrogenated poly(isoprene) "hPI". A striking correlation was established between surface wetting transition and mixtures of low compatibility, such as oligo-dIB in PB or PI. Segregation was quantified normal to the surface by ion beam analysis and neutron reflectometry and in some cases lateral segregation was observable by AFM. While surface segregation is driven by disparity in molecular weight in highly compatible systems this trend reverses as critical point is approached, and surface segregation increases with increasing oligomer molecular weight.

The compatibility and surface behavior of squalane–polybutadiene mixtures are studied by experimental cloud point and neutron reflectivity measurements, statistical associating fluid theory (SAFT), and molecular dynamics (MD) simulations. A SAFT-γ Mie model is shown to be successful in capturing the cloud point curves of squalane–polybutadiene and squalane–cis-polybutadiene binary mixtures, and the same SAFT-γ Mie model is used to develop a thermodynamically consistent top-down coarse-grained force field to describe squalane–polybutadiene. Coarse-grained molecular dynamics simulations are performed to study surface behavior for different concentrations of squalane, with the system exhibiting surface enrichment and a wetting transition. Simulated surface profiles are compared with those obtained by fitting to neutron reflectivity data obtained from thin films composed of deuterated squalane (d-sq)–polybutadiene. The presented top-down parametrization methodology is a fast and thermodynamically reliable approach for predicting properties of oligomer–polymer mixtures, which can be challenging for either theory or MD simulations alone.

Correction for 'Predicting oligomer/polymer compatibility and the impact on nanoscale segregation in thin films' by Elise F. D. Sabattié et al., Soft Matter, 2017, 13, 3580-3591.