All-conjugated block copolymers have significant potential for solution-processed optoelectronic applications, in particular those relying on a p/n junction. Herein, we report the synthesis and structure of all-conjugated diblock poly(3-hexylthiophene)-block-poly(9,9-dioctylfluorene) poly(3-hexylthiophene)-block-poly(9,9-dioctylfluorene-co-benzothiadiazole) thin films bulk. The are prepared using combination Grignard metathesis polymerization Suzuki polycondensation characterized with NMR...

Abstract In this study, inorganic silica nanoparticles are used to manipulate the morphology of 6,13‐bis(triisopropylsilylethynyl)‐pentacene (TIPS pentacene) thin films and performance solution‐processed organic thin‐film transistors (OTFTs). This approach is taken control crystal anisotropy, which origin poor consistency in TIPS pentacene based OTFT devices. Thin film active layers produced by drop‐casting mixtures SiO 2 pentacene. The resultant drop‐cast yield improved morphological...

We use 6,13-bis(triisopropylsilylethynyl)pentacene as a model small molecule organic semiconductor and two conjugated polymer additives to demonstrate polymer-mediated polymorphism of for the first time. The additives, used with slow solution crystallization approach, yield crystal structures that are not accessible by nonconjugated impart excellent long-range order. In both semiconductor/conjugated blends studied here, previously unreported polymorphs have been identified which also leads...

Molecular assemblies have been mainly researched in open spaces for a long time. However, recent research has revealed that there are many interesting aspects present regarding self-assemblies confined spaces. association within nanospaces such as mesoporous materials provides unusual phenomena based on highly restricted molecular motions. Current endeavors science and technology focused developing either new class of or with novel/multiple functionalities which is often achieved via...

The shear forces between polystyrene chains end-tethered to opposing surfaces have been measured with the surface apparatus (SFA) in both good and near-ϑ solvents. When shearing velocity was varied, complex polymer/solvent system responded a Newtonian-like fashion force increasing linearly velocity. effective viscosity of systems this regime found be an order magnitude greater than semidilute solutions equivalent molecular weight free chains. At larger velocities or higher extents...

Conjugated polymers are promising materials for organic electronic devices; however, to achieve metal-like electrical properties, these need be chemically doped. In this work, a series of structurally tailored thiophene-based copolymers studied elucidate relationships between copolymer design, doping method, solubility, and conductivity. The results show that increasing the distance side chains along conjugated backbone increases thin film conductivity, with conductivities surpassing...

Abstract Surface‐initiated photoiniferter‐mediated photopolymerization (SI‐PMP) in presence of tetraethylthiuram disulfide is used to directly synthesize surface‐grafted poly(methacrylic acid)‐ block ‐poly( N‐ isopropylacrylamide) (PMAA‐ b ‐PNIPAM) layers. The response these PMAA‐ ‐PNIPAM bi‐level brushes changes pH, temperature and ionic strength investigated by using in‐situ multi‐angle ellipsometry measure solvated layer thickness. As expected for a copolymer architecture, PMAA blocks...

Nanophase separation plays a critical role in the performance of donor–acceptor based organic photovoltaic (OPV) devices. Although post-fabrication annealing is often used to enhance OPV efficiency, ability exert precise control over phase separated domains and connectivity remains elusive. In this work, we use diblock copolymer systematically manipulate domain sizes an solar cell active layer at nanoscale. More specifically, poly(3-hexylthiophene)-b-poly(ethylene oxide) (P3HT-b-PEO) with...

We report a facile synthetic strategy based on grafting through approach to prepare well-defined molecular bottlebrushes composed of regioregular poly(3-hexylthiophene) (rr-P3HT) as the conjugated polymeric side chain. To this end, exo-norbornenyl-functionalized P3HT macromonomer was synthesized by Kumada catalyst transfer polycondensation (KCTP) followed postpolymerization modifications, and resulting successfully polymerized ring-opening metathesis polymerization (ROMP) in controlled...

The protein-adsorbing and -repelling properties of various smart nanometer-thin polymer brushes containing poly(N-isopropylacrylamide) poly(acrylic acid) with high potential for biosensing biomedical applications are studied by in situ infrared-spectroscopic ellipsometry (IRSE). IRSE is a highly sensitive nondestructive technique that allows protein adsorption on to be investigated an aqueous environment as external stimuli, such temperature pH, varied. These changes relevant conditions...

Understanding the effect of inhomogeneity on charge regulation and dielectric properties, how it depends conformational characteristics macromolecules is a long-standing problem. In order to address this problem, we have developed field-theory study local function in planar polyelectrolyte brushes. The theory used polyacid brush, which comprised chains end-grafted at solid-fluid interface, equilibrium with bulk solution containing monovalent salt ions, solvent molecules pH controlling acid....

The Quite Intense Kinetics Reflectometer (QIKR) will be a general-purpose, horizontal-sample-surface neutron reflectometer. Reflectometers measure the proportion of an incident probe beam reflected from surface as function wavevector (momentum) transfer to infer distribution and composition matter near interface. unique scattering properties neutrons make this technique especially useful in study soft matter, biomaterials, materials used energy storage. Exploiting increased brilliance...

Surface-tethered poly(methyl methacrylate) films were synthesized by surface-initiated photoiniferter-mediated photopolymerization (SI-PMP), and the kinetics of film growth followed measuring layer thickness as a function reaction time, monomer concentration, light intensity using variable angle ellipsometry. The initial rate had approximate first-order dependence on concentration. However, decreased with indicating presence termination reactions. To determine which reactions are prevalent,...

We report the controlled radical polymerization of 2-vinyl-4,4-dimethyl azlactone (VDMA), a 2-alkenyl-2-oxazolin-5-one monomer that contains polymerizable vinyl moiety and highly reactive, pendant azlactone, as well dilute solution properties surface attachment functionalization. Reversible addition−fragmentation chain transfer (RAFT) was used to polymerize VDMA in benzene at 65 °C using either 2-(2-cyanopropyl) dithiobenzoate (CPDB) or 2-dodecylsulfanylthiocarbonylsulfanyl-2-methylpropionic...

Through rigorous spectroscopic characterizations, including in situ, real-time monitoring, and size-exclusion chromatography (SEC) we describe the functionalization of polymers copolymers based on vinyl dimethyl azlactone (VDMA), as well modification VDMA monomer using efficient ring-opening strategies. Specifically, demonstrate VDMA-based materials by “pegylation”, base-catalyzed hydrolysis, nucleophilic addition short alkyl chains, fluorescent markers, motifs used to specifically bind...

Functional soft interfaces are of interest for a variety technologies. We describe three methods preparing substrates with alkyne groups, which show versatility "click" chemistry reactions. Two the have same root: formation thin, covalently attached, reactive interfacial layers poly(glycidyl methacrylate) (PGMA) via spin coating onto silicon wafers followed by modification either propargylamine or 5-hexynoic acid. The amine carboxylic acid moieties react epoxy groups PGMA, creating polymer...

We previously synthesized a series of potent and selective A3 adenosine receptor (AR) agonists (North-methanocarba nucleoside 5′-uronamides) containing dialkyne groups on extended adenine C2 substituents. coupled the distal alkyne 2-octadiynyl by Cu(I)-catalyzed "click" chemistry to azide-derivatized G4 (fourth-generation) PAMAM dendrimers form triazoles. A3AR activation was preserved in these multivalent conjugates, which bound with apparent Ki 0.1−0.3 nM. They were substituted moieties,...

Abstract The ability to prepare well‐defined semiconducting polymers is essential for understanding the link between structure and function in organic photovoltaic devices. A general, one‐pot method altering degree of functionality end‐functionalized poly(3‐hexylthiophene)s (P3HT) prepared by Grignard metathesis (GRIM) polymerization has been developed. In absence additives, end‐functional P3HTs quenching GRIM with a reagent dependent on utilized. this study, additives such as styrene...

The synthesis of well-defined, end-functional poly(3-hexylthiophene)s (P3HTs) by in situ quenching the Grignard metathesis (GRIM) polymerization is complicated extreme tendency to favor difunctional products all but a few cases. A facile one-pot method for preparing 2-pyridyl and 3-pyridyl P3HTs with high abundance monofunctional established via an examination kinetics end-functionalization reaction lithium chloride complexes 2- reagents. Density functional theory calculations guide...

The assembly of dually reactive, well-defined diblock copolymers incorporating the chemoselective/functional monomer, 4,4-dimethyl-2-vinylazlactone (VDMA) and surface-reactive monomer glycidyl methacrylate (GMA) is examined to understand how competition between surface attachment microphase segregation influences interfacial structure. Reaction PGMA block with hydroxyl groups not only anchors copolymer surface, but limits chain mobility, creating brush-like structures comprising PVDMA...

The impact of various polymeric compatibilizers, including end-functionalized P3HTs and diblock copolymers containing P3HT, on the structure function poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) bulk heterojunctions is presented. Careful analyses small angle neutron scattering curves provide a measure miscibility PCBM in average domain size, interfacial area between P3HT-rich phase uncompatibilized compatibilized systems. Differential scanning calorimetry...

Polymers exhibit deviations from their bulk physical properties in the vicinity of solid interfaces due to changes configurations, entanglements, and relaxation dynamics at interfacial regions. By comparing grafted nongrafted polymer nanocomposite systems based on poly(methyl methacrylate) silica, we show that distribution times exhibits both commonly reported slower mobility faster modes depend nature zone, matrix molecular weight, loading level nanomaterials. These findings are derived...

Abstract Summary: This contribution describes the graft polymerization of polystyrene (PS) by atom transfer radical at 50, 60, and 75 °C. Thick PS brushes were grown from initiator‐functionalized PGMA layers on silicon, constant growth rates provide indirect evidence that polymerizations controlled. Formation T < g ATRP styrene α ‐bromoester poly(glycidyl methacrylate) layers. magnified image

We have investigated the cause of catalyst deactivation observed during surface-confined atom-transfer radical polymerization acidic monomers. Surface-tethered polyelectrolyte layers poly(itaconic acid) and poly(methacrylic were grown from self-assembled initiator monolayers 2-bromoisobutyryl bromide terminated thiol molecules. This molecule a copper-based organometallic allowed tethered chains to be directly via at room temperature in aqueous solutions. Structural surface properties...

The complexity of the mineral–organic carbon interface may influence extent stabilization organic compounds in soils, which is important for global climate futures. nanoscale structure a model was examined here by depositing films contrasting chemical character, hydrophilic glucose and amphiphilic stearic acid, onto soil mineral analogue (Al2O3). Neutron reflectometry, technique provides depth-sensitive insight into organization thin films, indicates that molecules reside layer between Al2O3...