Selective adsorption behavior of polymer at the polymer–nanoparticle interface

Coarse‐grained molecular dynamics simulations are used to investigate the adsorption behavior of monodisperse and bidisperse polymer chains on the nanoparticle (NP) surface at various polymer–NP interactions, chain lengths, and stiffness. At a strong polymer–NP interaction, long chains preferentially occupy interfacial region and squeeze short chains out of the interfacial region. Semiflexible chains with proper stiffness wrap NPs dominantly in a helical fashion, whereas fully flexible chains constitute the surrounding matrix. As chain stiffness increases, the results of the preferential adsorption are the opposite. The chain‐length or chain‐stiffness‐induced selective adsorption behavior of polymer chains in the polymer–NP interfacial region relies on a delicate competition between entropic and enthalpic contributions to the total free energy. These results could provide insights into polymer–NP interfacial adsorption behavior and guide the design of high‐performance nanocomposites. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1829–1837     

Molecular dynamics simulation study of glass transition in hydrated Nafion

The thermal transition of Nafion is studied using a molecular dynamics simulation through a chemically realistic model. Static and dynamic properties of polymer melts with different water contents are investigated over a wide range of temperatures to obtain viscometric and calorimetric glass transition temperatures. The effect of cooling rate of the simulation on the glass transition of the hydrated polymer is also examined within the well‐known Williams–Landel–Ferry (WLF) equation. Variation of relaxation times versus temperature shows a fragile‐to‐strong transition. The hydration level has a significant impact on the static and dynamic properties of the polymer chains and water molecules confined in nanometric spaces between polymer chains. The results of this study are useful to predict the behavior of Nafion for various applications including fuel cells, sensors, actuators, and shape memory devices at different temperatures. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 907–915     

Effects of chain conformation and chain length on degree of aggregation in assembled particles of conjugated polymer in solvents–nonsolvent: A spectroscopic study

This article explores photophysical properties and aggregation behaviors of conjugated polymer, poly[2‐methoxy, 5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene](MEH?PPV), in various solvent–nonsolvent systems by utilizing UV/vis absorption and photoluminescence (PL) spectroscopy. The isolated chains of MEH‐PPV dispersed in solvents including dichloromethane, chloroform, and tetrahydrofuran adopt either extended or collapsed conformations depending on local polymer–solvent interactions. Aggregation of the MEH‐PPV in these solvents is induced by addition of a poor solvent, cyclohexane. The formation of aggregates is indicated by the appearance of distinct red‐shift peaks in the absorption and PL spectra. The degree of aggregation in each solvent–nonsolvent system is compared by means of absorbance and PL intensity of the aggregate bands. In early stage of the aggregation, the amount of aggregates in system is controlled by the solubility of polymer. When the polymer chains are forced to densely pack within assembled particles by increasing ratio of cyclohexane to 99 v/v %, the conformation of individual chain plays important role. We have found that the extended chains facilitate the aggregation in the assembled particles. Increasing chain length of polymer promotes the aggregation in early stage and densely packed particles. Size distribution of the assembled particles is also found to depend on the choice of solvent. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 894–904, 2010     

A facile “graft from” method to prepare molecular‐level dispersed graphene–polymer composites

Graphene–polymer composites of positive‐charged poly(dimethyl aminoethyl acrylate), negative‐charged poly(acrylic acid), and neutral polystyrene were prepared by “graft from” methodology using reversible addition fragmentation chain transfer (RAFT) polymerization via a pyrene functional RAFT agent (PFRA) modified graphene precursor. Fluorescence spectroscopy and attenuated total reflection infrared (ATR‐IR) evidenced that the PFRA was attached on the graphene basal planes by π–π stacking interactions, which is strong enough to anti‐dissociation in the polymerization mixture up to 80°C. Atomic force microscopy (AFM) revealed that the thickness of a graphene–polymer sheet was about 4.0 nm. Graphene composites of different polymers with the same polymerization degree exhibited similar conductivity; however, when the polymer chain was designed as random copolymer the conductivity was significantly decreased. It was also observed that the longer the grafted polymer chains the lower the conductivity. ATR‐IR spectroscopy and thermogravimetric analysis were also performed to characterize the as‐prepared composites. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Organizational stabilities of bulk neat and well‐mixed,blended polymer samples coalesced from their crystalline inclusion compounds formed with cyclodextrins

Cyclodextrins (CDs) are cyclic starches containing α‐1,4‐linked glucose units. Commonly available α‐, β‐, and γ‐CDs have six, seven, and eight glucose units, respectively. They are well known for forming noncovalent inclusion complexes (ICs) with a variety of guest molecules, including many polymers, by threading and inclusion into their relatively hydrophobic interior cavities, which are roughly cylindrical, with diameters of ～0.5–1.0 nm. Warm water washing of crystalline CD‐ICs containing polymer guests insoluble in water or treatment with amylase enzymes serve to remove the host CDs and result in the coalescence of the guest polymers into solid bulk samples. When guest polymers are coalesced from their CD‐ICs by carefully removing the host CD lattices, they are observed to solidify with structures, morphologies, and even conformations that are distinct from bulk samples made from their solutions and melts. In addition, molecularly mixed, intimate blends can be obtained upon coalescence of two or more normally immiscible polymer guests from their common CD‐ICs. Not only are the organizations and behaviors of bulk polymer samples significantly modified on coalescence from their CD‐ICs, but both are also maintained for significant periods of time even when heated above their T_gs and T_ms, where their chains are mobile. Here, we discuss the long‐time, high temperature stabilities of the organizations and properties of bulk polymers coalesced from their crystalline CD‐ICs. While random‐coiling of their initially coalesced, largely extended, separated, and unentangled chains may be relatively rapid, we conclude that the subsequent slow establishment of homogeneous melts or phase‐segregated blends results from the extremely sluggish center‐of‐mass diffusion that must accompany full entanglement of their chains. Apparently, the process of entangling the largely separated and not fully interpenetrating randomly coiled chains initially coalesced from their CD‐ICs is particularly slow, much slower in fact than the center‐of mass diffusion of polymer chains in their fully entangled melts. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1543–1553, 2009     

Morphological studies of blends of conjugated polymers and acceptor molecules using langevin dynamics simulations

We use coarse‐grained Langevin dynamics simulations of blends of generic conjugated polymers and acceptor molecules to show how architecture (e.g., side chains, backbone flexibility of oligomers) and the pair‐wise interactions between the constituents of the blend affect morphology and phase transition. Alkyl side chains on the conjugated oligomer backbones shift the liquid crystal (LC) transition temperature from that of bare conjugated backbones and the direction of the shift depends on backbone–backbone interactions. Rigid backbones and constrained side chains cause a layer‐by‐layer morphology of conjugated polymers and amorphous acceptors, whereas flexible backbones and unconstrained side chains facilitate highly ordered acceptor arrangement. Strong backbone–backbone attraction shifts LC transition to higher temperatures than weak backbone–backbone attraction, and strong acceptor–acceptor attraction increases acceptor aggregation. Pure macro‐phase separated domains form when all pair‐wise interactions in the blend are strongly attractive, whereas interconnected domains form at intermediate acceptor–acceptor attraction and strong polymer–polymer attractions. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013     

Synthesis and double doping behavior of a poly(p‐phenylenevinylene)s bearing conjugated side chains

A poly(p‐phenylenevinylene) derivative bearing conjugated side chains (polyCPV) was synthesized by Migita‐Kosugi‐Stille type coupling polycondensation reaction. This polymer contains phenylenevinylene units in both the main chain and the side chains. UV–vis absorption and fluorescence emission spectroscopies revealed a well‐developed π‐conjugation of the polyCPV. The absorption band of the polymer was extended to long wavelengths. A fluorescent emission maximum of polyCPV is located at considerably longer wavelengths than that of the conjugated side chain monomer. Electron spin resonance measurements of polyCPV confirmed generation of charge species in both the main chain and the side chains via iodine doping. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

High water content clay–nanocomposite hydrogels incorporating guanidinium‐pendant methacrylamide: Tuning of mechanical and swelling properties by supramolecular approach

Novel clay–polymer composite hydrogels with high water content (up to 98 wt %) are developed, in which mechanical properties are reinforced by the formation of multiple ion‐pairs between the polymer chains and clay nanosheets (CNS). When a small amount of guanidinium‐pendant methacrylamide (0.1–0.2 wt %) is copolymerized with a neutral monomer (0.5–2.0 wt %) in an aqueous dispersion of CNS (1.0–3.0 wt %), a self‐standing hydrogel with satisfactory mechanical toughness and elasticity results, despite its high water content (95–98 wt %). The mechanical properties and swelling behaviors of the hydrogels can be tuned by the amount of the guanidinium‐pendant acrylamide. A systematic study indicates that the ion pairs, formed between the guanidinium groups in the polymer chains and the oxyanions on the surfaces of the CNS, serve as crosslinking points in the three‐dimensional network developed in these hydrogels. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 839–847     

Short‐time elasticity of polymer melts: Tobolsky conjecture and heterogeneous local stiffness

An extended molecular‐dynamics study of the short‐time “glassy” elasticity exhibited by a polymer melt of linear fully‐flexible chains above the glass transition is presented. The focus is on the infinite‐frequency shear modulus G_∞ manifested in the picosecond time scale and the relaxed plateau G_p reached at later times and terminated by the structural relaxation. The local stiffness of the interactions with the first neighbors of each monomer exhibits marked distribution with average value given by G_∞. In particular, the neighborhood of the end monomers of each chain are softer than the one of the inner monomers, so that G_∞ increases with the chain length. G_p is not affected by the chain length and is largely set by the nonbonding interactions, thus confirming for polymer melts the conjecture formulated by Tobolsky for glassy polymers. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1401–1407     

Influence of the bulkiness of the substituent on the aggregation and magnetic properties of poly(3‐alkylthiophene)s

A series of poly(3‐alkylthiophene)s (P3ATs) ( P1–P5 ) has been synthesized via a Ni(dppp)‐mediated polymerization, varying the bulkiness of the alkyl side chains in order to investigate the influence of the bulkiness of the alkyl substituent on the aggregation and magnetic properties of P3ATs. UV–Vis spectroscopy, performed in solution as well as in film, shows that the stacking of the polymers becomes more complicated as the bulkiness of the side chains increases. Both the π‐interactions and the planarization of the polymer chains are diminished. While aggregation is absent in poor solvent for the polymer with the most bulky side chains, aggregation was present in film, albeit slowed down. This behavior was also confirmed by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) experiments. Electron spin resonance (ESR) measurements, performed at 300 K on powders, confirmed the trend of decreasing supramolecular order with increasing bulkiness of the side‐chain. Magnetization measurements, performed at 5 and 300 K, are in line with our hypothesis on the influence of π‐interactions and the fraction of planar polymer chains on the coercivity and saturation magnetization, respectively. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 76–86     

A vinylene‐linked benzo[1,2‐b:4,5‐b']dithiophene‐2,1,3‐benzothiadiazole low‐bandgap polymer

A new heteroarylene‐vinylene donor–acceptor polymer P(BDT‐V‐BTD) with reduced bandgap has been synthesized and its photophysical, electronic and photovoltaic properties investigated both experimentally and theoretically. The structure of the polymer comprises an unprecedented combination of a strong donor (4,8‐dialkoxy‐benzo[1,2‐b:4,5‐b']dithiophene, BDT), a strong acceptor (2,1,3‐benzothiadiazole, BTD) and a vinylene spacer. The new polymer was obtained by a metal‐catalyzed cross‐coupling Stille reaction and fully characterized by NMR, UV–vis absorption, GPC, TGA, DSC and electrochemistry. Detailed ab initio computations with solvation effects have been performed for the monomer and model oligomers. The electrochemical investigation has ascertained the ambipolar character of the polymer and energetic values of HOMO, LUMO and bandgap matching materials‐design rules for optimized organic photovoltaic devices. The HOMO and LUMO energies are consistently lower than those of previous heteroarylene‐vinylene polymer while the introduction of the vinylene spacer afforded lower bandgaps compared to the analogous system P(BDT‐BTD) with no spacer between the aromatic rings. These superior properties should allow for enhanced photovoltages and photocurrents in photovoltaic devices in combination with PCBM. Preliminary photovoltaic investigation afforded relatively modest power conversion efficiencies of 0.74% (AM 1.5G, 100 mW/cm²), albeit higher than that of previous heteroarylene‐vinylene polymers and comparable to that of P(BDT‐BTD). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Microporous polyurethanes: Synthesis and investigation of the mechanism of the pore formation

A new approach for microporous polymeric material is developed utilizing the secondary interactions such as hydrogen bonding in the polymer chains in polyurethane systems at ambient conditions. A new series of highly rigid, thermally stable, and readily soluble cycloaliphatic polyurethanes were designed and synthesized for this purpose, based on new tricyclodecanedimethanol and 1,4‐cyclohexanedimethanol. The hydrogen‐bonding interactions induce phase separation in solution, which leads to polymer‐rich and solvent‐rich domains; subsequent evaporation of the solvent molecules results in micropores. The phase‐separation process in the polyurethane is found to be highly dependent on the chemical structures of the polymer chain backbone. ¹H NMR titration experiments were carried out to understand the mechanism of the micropore formation and its dependence on different structural subunits. The hydrogen‐bonding association constant (K) obtained from the titration experiments revealed that higher the K‐value more the tendency to form micropores. A fully cycloaliphatic polyurethane produces micropores of sizes ranging from 1 to 8 μm, and each pore is separated by 10^?20 μm, whereas the replacement of one of the cyclic unit in the backbone disturbs the entire phase‐separation process and results in nonporous morphology. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1296–1308, 2006     

Light‐driven atom transfer radical polymerization on supramolecular complexes of conjugated polymers and single‐walled carbon nanotubes

Previous approaches used to decorate latently reactive conjugated polymer‐coated carbon nanotube complexes have utilized “grafting‐to” strategies. Here, we coat the carbon nanotube surface with a conjugated polymer whose side chains contain the radical initiator, α‐bromoisobutyrate, which enables atom transfer radical polymerization (ATRP) from the polymer–nanotube surface. Using light to generate Cu(I) in situ, ATRP is used to grow narrow dispersity polymer chains from the polymer–nanotube surface. We confirm the successful polymerization of (meth)acrylates from the polymer–nanotube surface using a combination of gel permeation chromatography and infrared spectroscopy. Strikingly, we demonstrate that nanotube optoelectronic properties are preserved after radical‐mediated polymer grafting using Raman spectroscopy and photoluminescence mapping. Overall, this work elucidates a method to grow narrow dispersity polymer chains from the polymer–nanotube surface using light‐driven radical chemistry, with concurrent preservation of nanotube optoelectronic properties. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2015–2020     

Dynamic modeling of the morphology of latex particles with in situ formation of graft copolymer

Modification of the polymer–polymer interfacial tension is a way to tailor‐make particle morphology of waterborne polymer–polymer hybrids. This allows achieving a broader spectrum of application properties and maximizing the synergy of the positive properties of both polymers, avoiding their drawbacks. In situ formation of graft copolymer during polymerization is an efficient way to modify the polymer–polymer interfacial tension. Currently, no dynamic model is available for polymer–polymer hybrids in which a graft copolymer is generated during polymerization. In this article, a novel model based on stochastic dynamics is developed for predicting the dynamics of the development of particle morphology for composite waterborne systems in which a graft copolymer is produced in situ during the process. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Polymers coalesced from their cyclodextrin inclusion complexes: What can they tell us about the morphology of melt‐crystallized polymers?

Cyclodextrins (CDs) are cyclic polysaccharides with nano‐size, largely hydrophobic cavities, and exteriors covered with hydrophilic hydroxyl groups, making them water soluble. Threading and filling their cavities with polymer chains produces noncovalently bonded crystalline inclusion compounds (ICs). In this study, we formed fully covered, stoichiometric ICs between guest poly(L ‐lactic acid), poly(ε‐caprolactone), and nylon‐6 chains and host α‐CD. Coalesced samples of all three polymers were obtained after appropriately removing the stacked α‐CD host channels from their ICs. Distinct differential scanning calorimetriy (DSC) thermograms were observed for as‐received and coalesced samples, with the coalesced samples crystallizing faster at higher temperatures from their melts, and this distinction was maintained even after extensive, long‐time melt‐annealing (hours, days, and weeks). We believe this is due to the largely unentangled chains with extended conformations that are more densely packed in the initially coalesced samples. When small amounts (～2 wt %) of the coalesced polymers are used as self‐nucleating agents for their as‐received samples, the resulting self‐nucleated samples show DSC thermograms similar to those of the neat coalesced polymers, including their long‐time stability to melt‐annealing. Coalesced polymers, whether neat or in samples they self‐nucleate, may conserve their organization in the melt (largely extended and unentangled chains) for long periods, because the process of entangling the many chains influenced by a single initially extended unentangled coalesced chain, after it randomly coils, is extremely sluggish. By contrast, in melt‐crystallized or solution‐cast samples, polymer chains generally become fully randomly coiled, interpenetrate, and entangle after being heated and held in their melts for comparatively much shorter times. For example, we have recently observed (DSC) that ultra high molecular weight, gel‐spun spectra polyethylene (PE) fibers^® did not conserve or retain any memory of their as‐spun and highly drawn semicrystalline morphology even after spending as little as 2 min in the melt. As a consequence of the comparison to the behavior of coalesced polymer melts, we believe that polyethylene chains in Spectra fibers^® must be at least intimately dispersed within their crystalline regions, and likely partially coiled and entangled in their noncrystalline regions, thereby facilitating their rapid transformation into a full entanglement network of randomly coiling chains in the melt. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

Physically cross‐linked networks of POSS‐capped poly(acrylate amide)s: Synthesis,morphologies, and shape memory behavior

In this work, we synthesized a novel organic–inorganic semitelechelic polymer from polyhedral oligomeric silsesquioxane (POSS) and poly(acrylate amide) (PAA) via reversible addition‐fragmentation chain transfer (RAFT) polymerization. The organic–inorganic semitelechelic polymers have been characterized by means of nuclear magnetic resonance spectroscopy, thermal gravimetric analysis, and dynamic mechanical thermal analysis. It was found that capping POSS groups to the single ends of PAA chains caused a series of significant changes in the morphologies and thermomechanical properties of the polymer. The organic–inorganic semitelechelics were microphase‐separated; the POSS microdomains were formed via the POSS–POSS interactions. In a selective solvent (e.g., methanol), the organic–inorganic semitelechelics can be self‐assembled into the micelle‐like nanoobjects. Compared to plain PAA, the POSS‐capped PAAs significantly displayed improved surface hydrophobicity as evidenced by the measurements of static contact angles and surface atomic force microscopy. More importantly, the organic–inorganic semitelechelics displayed typical shape memory properties, which was in marked contrast to plain PAA. The shape memory behavior is attributable to the formation of the physically cross‐linked networks from the combination of the POSS–POSS interactions with the intermolecular hydrogen‐bonding interactions in the organic–inorganic semitelechelics. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 587–600     

3,6‐Dialkylthieno[3,2‐b]thiophene moiety as a soluble and electron donating unit preserving the coplanarity of photovoltaic low band gap copolymers

It has been shown recently, that the presence of alkyl side chains at the 3‐positions on the thiophene rings placed next to 2,1,3‐benzothiadiazole core in the backbone of several conjugated polymers results in severe steric hindrance and prevents efficient planarity of the thiophene‐2,1,3‐benzothiadiazole‐thiophene (TBzT) segment. Both properties have a strong influence on the optoelectronic properties of the polymer and need to be considered when the polymer is to be used for organic electronics applications. In this work, we modified a previously synthesized oligothiophene copolymer, consisting of two 3,4′‐dialkyl‐2,2′‐bithiophene units attached to a 2,1,3‐benzothiadiazole unit (TBzT segment) and a thieno[3,2‐b]thiophene unit, by optimizing the lateral alkyl side chains following a density functional theory investigation. It is demonstrated that eliminating the alkyl side chains from the 3‐positions of the TBzT segment and anchoring them onto the thieno[3,2‐b]thiophene, using an efficient synthesis of the 3,6‐dihexylthieno[3,2‐b]thiophene unit, allows us to reduce the energy band gap. In addition, the chemical modification leads to a better charge transport and to an enhanced photovoltaic efficiency of polymer/fullerene blends. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Amphiphilic Block‐Graft Copolymers Poly(ethylene glycol)‐b‐(polycarbonates‐g‐palmitate) Prepared via the Combination of Ring‐Opening Polymerization and Click Chemistry

Amphiphilic block‐graft copolymers mPEG‐b‐P(DTC‐ADTC‐g‐Pal) were synthesized by ring‐opening polymerization of 2,2‐dimethyltrimethylene carbonate (DTC) and 2,2‐bis(azidomethyl)trimethylene carbonate (ADTC) with poly(ethylene glycol) monomethyl ether (mPEG) as an initiator, followed by the click reaction of propargyl palmitate and the pendant azido groups on the polymer chains. Stable micelle solutions of the amphiphilic block‐graft copolymers could be prepared by adding water to a THF solution of the polymer followed by the removal of the organic solvent by dialysis. Dynamic light scattering measurements showed that the micelles had a narrow size distribution. Transmission electron microscopy images displayed that the micelles were in spherical shape. The grafted structure could enhance the interaction of polymer chains with drug molecules and improve the drug‐loading capacity and entrapment efficiency. Further, the amphiphilic block‐graft copolymers mPEG‐b‐P(DTC‐ADTC‐g‐Pal) were low cytotoxic and had more sustained drug release behavior. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Orientation control in nanoparticle filled block copolymer cold zone annealed films

Nanoparticles provide an attractive route to modifying polymer thin film properties, yet controlling the dispersion and morphology of functionalized nanoparticle filled films is often difficult. Block copolymers can provide an ideal template for directed assembly of nanoparticles under controlled nanoparticle‐polymer interactions. Previously we observed that neat films of cylinder forming poly(styrene‐b‐methyl methacrylate) PS‐b‐PMMA block copolymer (c‐BCP) orient vertically with dynamic sharp thermal cold zone annealing (CZA‐S) over wide range of CZA‐S speed (0.1–10) μm/s. Here, we introduce a low concentration (1–5 wt %) of nanoparticles of phenolic group functionalized CdS (fCdS‐NP), to PMMA cylinder forming polystyrene‐b‐poly (methyl methacrylate) block copolymer (c‐BCP) films. Addition of the fCdS‐NP induces a vertical to horizontal orientation transition at low CZA‐S speed, V = 5 μm/s. The orientation flip studies were analyzed using AFM and GISAXS. These results confirm generality of our previously observed orientation transition in c‐BCP under low speed CZA‐S with other nanoparticles (gold [Au‐NP], fulleropyrrolidine [NCPF‐NP]) in the same concentration range, but reveal new aspects not previously examined: (1) A novel observation of significant vertical order recovery from 5–10% vertical cylindrical fraction at V = 5 μm/s to 46–63% vertical cylindrical fraction occurring at high CZA‐S speed, V = 10 μm/s for the fCdS nanoparticle filled films. (2) We rule out the possibility that a nanoparticle wetting layer on the substrate is responsible for the vertical to horizontal flipping transition. (3) We demonstrate that the orientation flipping results can be achieved in a nanoparticle block copolymer system where the nanoparticles are apparently better‐dispersed within only one (matrix PS) domain unlike our previous nanoparticle system studied. We consider facile processing conditions to fabricate functionalized nanoparticles filled PS‐PMMA block copolymer films with controlled anisotropy, a useful strategy in the design of next generation electronic and photonic materials. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 604–614