Polystyrene Backbone Research Articles

Rational Design of Carbazole- and Carboline-Based Polymeric Host Materials for Realizing High-Efficiency Solution-Processed Thermally Activated Delayed Fluorescence Organic Light-Emitting Diode.

Recently, various host materials have been developed for solution-processed thermally activated delayed fluorescent organic light-emitting diodes (TADF-OLEDs). Compared with small-molecule hosts, polymeric hosts are advantageous for inducing a uniform distribution and segregation of dopant molecules in the emissive layer without undesired large-scale phase separation. In this study, new polymer hosts were demonstrated, in which a bipolar conjugative moiety consisting of a carbazole (Cz) donor and an α-carboline (α-Cb) acceptor was bound to the polystyrene backbone through a non-conjugated linker. They exhibited high triplet energies of >2.8 eV, and their emission spectra overlapped with the absorption spectrum of a green TADF emitter, which allowed facile energy transfer from the polymeric host to the small-molecule dopants. High device performance was observed, with external quantum efficiencies (EQEs) of 13.65, 17.09, and 17.48% for solution-processed green TADF-OLEDs using PSCzCz, PSCzCb, and PSCbCz, respectively, as hosts for the EML. The EQEs of bipolar host (PSCzCb and PSCbCz)-based devices were higher than those of unipolar host (poly(N-vinylcarbazole) and PSCzCz)-based devices owing to the well-balanced charge-carrier transport. According to these results, the polymeric host bearing a bipolar Cz and α-Cb coupled moiety is a promising material for solution-processable TADF-OLEDs.

Synthesis and Electroluminescent Properties of Through-Space Charge Transfer Polymers Containing Acridan Donor and Triarylboron Acceptors.

We report the design, synthesis and electroluminescent properties of three kinds of through-space charge transfer (TSCT) polymers consisting of non-conjugated polystyrene backbone, acridan donor and triarylboron acceptors having different substituents such as hydrogen (H), fluorine (F), and trifluoromethyl (CF3). Owing to the weak electron interaction between acridan donor and triarylboron acceptor through non-conjugated connection, blue emission with peaks in range of 429–483 nm can be achieved for the polymers in solid-state film, accompanied with photoluminescence quantum yields of 26–53%. The resulting TSCT polymers exhibit small ΔEST values below 0.1 eV owing to the separated HOMO and LUMO distributions, showing thermally activated delayed fluorescence with lifetimes in range of 0.19–0.98 μs. Meanwhile, the polymers show aggregation-induced emission (AIE) effect with the emission intensity increased by up to ~33 folds from solution to aggregation state. Solution-processed organic light-emitting diodes based on the polymers containing trifluoromethyl substituent exhibit promising electroluminescent performance with maximum luminous efficiency of 20.1 cd A−1 and maximum external quantum efficiency of 7.0%, indicating that they are good candidates for development of luminescent polymers.

Taste Masking of Nizatidine Using Ion-Exchange Resins

The purpose of this study was to mask the bitter taste of nizatidine (NZD) using cation-exchange resins. Amberlite IRP-69 and Dowex-50 containing cross-linked polystyrene backbones were used. The drug resin complexes were prepared by batch process using drug: resin ratios of 1:1, 1:3, and 1:5. The optimum drug: resin ratio and the time required for maximum percentage drug loading into the complexes were determined. The selected drug-resin complexes were evaluated for morphology, drug release, and taste. The NZD-Dowex complex was obtained at a drug: resin ratio of 1:5 using a stirring time of 1 h in order to get 100% loading of NZD. The NZD-Dowex complex had a spherical shape and smooth texture similar to Dowex resin. The NZD-Dowex complex with a ratio of 1:5 showed that in vitro drug release of 4.27% at 5 min in simulated salivary fluid of pH 6.8 and 99.67% at 1 h in simulated gastric fluid of pH 1.2. NZD’s bitter taste was effectively masked when it formed a complex with Dowex at a ratio of 1:5. This was proved by an electronic tongue and human test panel.

Preparation and Morphologies of AB6¯ Block‐Graft Copolymers

ABSTRACTMicrophase‐separated structures of a series of AB6 block‐graft copolymers were studied by TEM and SAXS. Ten copolymers with the same polystyrene (S) backbone and six polyisoprene (I) grafts on the average but with different graft chain lengths were carefully synthesized by living anionic polymerization, covering the range 0.21 ≤ ϕS ≤ 0.90, where ϕS denotes polystyrene compositions. From TEM observation of the AB6 block‐graft copolymers, it turns out to be clear that they show four microphase‐separated structures, S‐spheres, S‐cylinders(S‐prisms), alternative lamellae, and I‐cylinders. Among them, for example, the samples with 0.54 ≤ ϕS ≤ 0.58 shows prism structures whose cross sections of the S domains are close to hexagons, not circles, due to packing frustration of grafts. Composition dependence of morphologies of the present AB6 block‐graft copolymers reveals their phase diagram is extremely asymmetric with respect to ϕS = 0.5. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 952–960

N-cyclic quaternary ammonium-functionalized anion exchange membrane with improved alkaline stability enabled by aryl-ether free polymer backbones for alkaline fuel cells

To realize highly stable anion exchange membrane for alkaline fuel cells, aryl-ether free polystyrene (PS) was employed as polymer backbone and functionalized with alkaline stable N-cyclic quaternary ammonium (QA), e.g. six-membered (DMP) and bis-six-membered N-cyclic QA (ASU) cations via “click chemistry”. Surprisingly, aryl-ether free PS backbone having ASU cation displayed excellent chemical resistance in 1 M NaOH CD3OD/D2O solution at 80 °C even for 3000 h without obvious degradation, as confirmed by NMR spectroscopy. After blending with poly(styrene-ethylene-co-butylene-styrene) (SEBS) copolymer which improved the film-forming ability due to the poor mechanical properties of PS, the ASU-based blended membrane (SEBS/PS-ASU) having SEBS polymer of 10 wt% possessed the hydroxide conductivity of 31.6 mS/cm with an ion exchange capacity (IEC) of 1.76 meq./g. This value was higher than the blended membrane having DMP cations (25.8 mS/cm with a IEC of 1.92 meq./g). Similar behavior has been observed for the PPO system having the same functional cations. It was believed that the high water uptake of ASU-based membrane resulted in the higher ion conductivity. Remarkably, 92.4% of initial hydroxide conductivity was retained for SEBS/PS-ASU membrane with aryl-ether free PS backbone after storage in 1 M NaOH at 80 °C for 900 h, indicating the higher alkaline stability over the AEM counterpart with aromatic PPO polymer backbones having aryl ether bonds (21.0% retention in conductivity under the same test conditions). And the accelerated stability test in 5 M NaOH at 80 °C demonstrated that only 16.8% of loss in conductivity was observed after 1800 h of testing for the blend AEMs having ASU cations. Furthermore, as ionomers in catalyst layers, the ASU-functionalized PS copolymers showed a peak power density of 130 mW/cm2 at a current density of 210 mA/cm2.

Developing Through‐Space Charge Transfer Polymers as a General Approach to Realize Full‐Color and White Emission with Thermally Activated Delayed Fluorescence

AbstractThrough‐space charge transfer polymers (TSCT polymers) that contain a non‐conjugated polystyrene backbone and spatially separated donor and acceptor units for solution‐processed OLEDs with full‐color and white emission is reported. By tuning the charge transfer strength between donor and acceptors with different electron‐accepting ability, emission color spanning from deep blue to red can be achieved. By incorporating two kinds of donor/acceptor pairs in one polymer to create duplex through‐space charge‐transfer channels, blue and yellow emission can be simultaneously obtained to realize white electroluminescence from a single polymer. The TSCT polymers exhibit thermally activated delayed fluorescence effect with delayed‐component lifetimes in range of 0.36–1.98 μs, and unexpected aggregation‐induced emission (emission intensity enhancement of up to 117 from solution to aggregation state).

Developing Through-Space Charge Transfer Polymers as a General Approach to Realize Full-Color and White Emission with Thermally Activated Delayed Fluorescence.

Through-space charge transfer polymers (TSCT polymers) that contain a non-conjugated polystyrene backbone and spatially separated donor and acceptor units for solution-processed OLEDs with full-color and white emission is reported. By tuning the charge transfer strength between donor and acceptors with different electron-accepting ability, emission color spanning from deep blue to red can be achieved. By incorporating two kinds of donor/acceptor pairs in one polymer to create duplex through-space charge-transfer channels, blue and yellow emission can be simultaneously obtained to realize white electroluminescence from a single polymer. The TSCT polymers exhibit thermally activated delayed fluorescence effect with delayed-component lifetimes in range of 0.36-1.98 μs, and unexpected aggregation-induced emission (emission intensity enhancement of up to 117 from solution to aggregation state).

Mapping the Compaction of Discrete Polymer Chains by Size Exclusion Chromatography Coupled to High-Resolution Mass Spectrometry

We introduce a powerful approach based on the combination of size exclusion chromatography with high-resolution mass spectrometry to selectively follow the compaction of discrete polymer chains that have uniform elemental composition. Single-chain nanoparticles (SCNP) have attracted considerable interest for a wide range of applications associated with their adjustable morphology. However, the precise characterization of morphological changes during the compaction is still challenging using existing analysis techniques. We employ a polystyrene backbone functionalized with tetrazole and fumarate moieties to utilize the nitrile imine-mediated tetrazole-ene cycloaddition for compaction. As every compaction step is associated with an elimination of one nitrogen molecule, it can be monitored via high-resolution electrospray ionization mass spectrometry. The combination with size exclusion chromatography enables the direct correlation of changes in mass with changes in morphology associated with the compaction. By establishing a calibration between the retention time and the hydrodynamic radius, ion chromatograms of discrete chains can be directly applied to determine the reduction in hydrodynamic radius associated with each cross-linking event. Therefore, accessing the compaction of discrete polymer chains becomes possible for the first time.

Thermal degradation kinetic, electrical and dielectric behavior of brush copolymer with a polystyrene backbone and polyacrylate-amide side chains/ nanographene-filled composites

A brush copolymer having polystyrene backbone and flexible PA-amide (polyacrylate-amide) brushes that exhibit thermoplastic elastomer property was synthesized, and brush copolymer composites with nanographene in various ratios were prepared. The thermal properties of the macroinitiator, brush copolymer and composites were investigated using differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). The activation energy (Ea) of thermal decomposition of brush copolymer/6 wt% nanographene was estimated by the Flynn-Wall-Ozawa method, and the average activation energy value for the 0.1–0.7 conversion was estimated as being 141.7 kJ/mol. Electrically conducting nanographene-based brush copolymer composites were produced. DC and AC electrical conductivity and dielectric properties of permittivity of nanographene-based brush copolymer composites were investigated. Further, the activation energy profile of different nanographene/brush copolymer composites were determined by measuring DC conductivity of individual composite materials. A heterojunction diode made from the polymer nanographene composites were magnified on a p-type Si substrate using a hydro/solvo thermal method. The polymer composite/p-Si thin film heterojunction diode properties were studied using current-voltage (I-V) and capacitance-voltage (C-V) analysis.

Unexpected foaming behavior of heterografted comb-like PS-g-(PS/PE) copolymers with high branching density at semi-solid state under CO2 batching foam

The CO2 batching foaming behavior of heterografted comb copolymers (PS-g-(PS/PE)) with high branching density, which consisted of mixed polystyrene (PS) and semicrystalline polyethylene (PE) branching chains linked to PS backbone, were explored. Especially the effect of foaming temperature on CO2 batching foaming behavior of PS-g-(PS/PE) copolymers was deeply studied. Under the same saturation pressure and time (CO2 pressure: 13.3 MPa; saturation time: 5.5 h), the state of the samples changed with the foaming temperature (50–110 °C) from solid state to semi-solid state and finally melt state, resulting in different foaming behavior. When the foaming temperature was lower than 50 °C, all the samples (solid state) did not form foamed or porous structures. At above 60 °C, the foaming behavior of the samples strongly depended on the foaming temperature. Very surprisingly, at 60 °C, PS-g-(PS/PE) copolymers with lamellar microphase structure easily formed bimodal nanoporous structure (open-cell) composed of nanofibers, while PS-g-(PS/PE) copolymers with cylindric microphase structure also formed bimodal porous structure with larger size, but the open degree of cell wall was decreased, in which the nanofibers almost disappeared and a lot of nanosized domains appeared. When the foaming temperature was higher than 70 °C, the cell size increased and the cell density decreased with increasing foaming temperature. Furthermore, the cell structure changed from opened (porous) structure to closed structure when the foaming temperature rose, which was different from the results in the previous reports. The influence of foaming temperature on the foaming behavior of PS-g-(PS/PE) copolymers was discussed.

Effect of the Backbone Tether on the Electrochemical Properties of Soluble Cyclopropenium Redox-Active Polymers

Few reports to date have focused on the chemical and electrochemical reversibility of redox pendants assembled into soluble redox-active polymers (RAPs). Here we report a series of soluble RAPs for flow battery applications designed with cyclopropenium (CP) pendants. The tether length between CP and a polystyrene backbone was varied and found to influence electrochemical activity and stability. Different tether lengths of x methylene groups (x = 1–7) were simulated, and x = 1, 5, and 7 were synthesized to evaluate experimentally. This study illustrates that polymers with extended tether groups display an improved reversibility in cyclic voltammetry. The behavior is mirrored in the stability of the charged state tested in galvanostatic half-cells. When paired with a viologen polymer, these CP-based polymers produce a 1.55 V nonaqueous flow battery. The capacity decays for the polymers were structure-dependent, which provides empirical insight into materials design for high potential catholyte polymers.

Morphology and linear rheology of comb-like copolymer melts with high grafting density: Ⅱ. Heterografted PVSt-g-(PS/PE) comb-like copolymer with short backbone and mixed side chains

A series of heterografted PVSt-g-(PS/PE) based on polystyrene (PS) backbone with mixed PS and polyethylene (PE) side chains was obtained, in which the branching density of PVSt-g-(PS/PE) was above 72%. Because of the extremely short backbone, long side chains and high branching density in these comb-like copolymers, the topological structure of PVSt-g-(PS/PE) was similar to asymmetrical star copolymers. By adjusting the molar ratio of PS and PE side chains, the total PS (PVSt backbone + side chain PS) volume fraction in the graft copolymers could be adjusted. PVSt-g-(PS/PE) showed a microphase-separated structure at the melt state, depending on the composition of the copolymers. When the volume fraction of PS changed from 42.7% to 76.9%, the microphase-separated structures changed from lamellar phase structure to cylindrical morphology. Furthermore, all the PVSt-g-(PS/PE) samples with the microphase-separated structure showed a typical rheological behavior of cross-linked network-like structure, but the change trend of melt elasticity of the copolymer with increasing temperature depended on the microphase-separated structure.

Preparation and thermal properties of a novel core‐shell structure flame‐retardant copolymer

In order to improve the flame retardancy of polystyrene (PS), a phosphorus and nitrogen comonomer, named AC2NP2, was synthesized and then incorporated into various amounts of PS by seeded emulsion polymerization. The modified methacrylate (AC2NP2) was used as the core phase, the styrene as the shell phase, then flame‐retardant effect copolymers with core‐shell structure were prepared successfully. The particle size was ranged from 40 to 60 nm, and the structure and properties of the copolymers were characterized in detail. Notably, despite a few amounts of the AC2NP2 units in the copolymers, all the copolymers exhibited significantly enhanced thermal stability and reduced flammability as compared with pure PS. Furthermore, from differential scanning calorimetry test, it was observed that the glass transition temperature was tinily influenced with the incorporation of commoner. The incorporation of P‐N comonomer into PS backbone did not lead to negative effect on the glass transition behavior of PS.

Self-crosslinking of comb-shaped polystyrene anion exchange membranes for alkaline fuel cell application

A series of crosslinked, comb-shaped polystyrene (PS) anion exchange membranes (AEMs) having C-16 alkyl side chain were synthesized by a Cu(I)-catalyzed “click chemistry” reaction, and subsequently azide-assisted self-crosslinking for alkaline fuel cell application. The as-obtained crosslinked AEMs showed lower water uptake, and thus good dimensional stability as a result of crosslinking. The chemical stabilities of the AEMs were evaluated under severe conditions, and minor degradation was observed by measuring IEC and ion conductivity changes after stability testing. The crosslinked membranes retained their high ion conductivity even in 10M NaOH at 80°C for 400h. Moreover, the PS-based AEMs shown higher hydroxide conductivity than that of the AEMs based on poly(2,6-dimethyl-phenylene oxide) (PPO) with similar architecture under the same testing condition probably due to the excellent compatibility between polystyrene backbone and alkyl side chain which may have helped to build a more efficient morphology for water uptake and thus the ion transport. These crosslinked cationic polymers were employed as membranes for alkaline fuel cells. The results indicated that the AEMs based on PPO having C-16 alkyl side chain had not initial performance, e.g. no open circuit voltage (OCV). In contrast, the initial fuel cell performance with the peak power density of 88mW/cm2 was observed for the alkaline fuel cell with xPS-65 membrane. It is assumed that the polystyrene polymer backbone may have helped to build a more efficient phase boundary between the catalyst layer and membrane probably resulted from the high water uptake though a more complete study would be needed to explain this phenomenon.

Structural, Viscoelastic, and Electrochemical Characteristics of Self-Assembled Amphiphilic Comblike Copolymers in Aqueous Solutions.

Self-assembly in aqueous solutions of an amphiphilic comblike polyelectrolyte (80C12) that consists of a polystyrene (PS) backbone onto which quaternary ammonium pendant moieties have been grafted has been investigated by light scattering and cryo-transmission electron microscopy measurements in the presence of KCl and methylviologen dication (MV2+) under conditions mimicking those for electrochemical measurements. Polymer chains self-assemble within branched cylindrical micelles that display viscoelastic properties, characterized by a relaxation time of 4 s. To tune this time, 80C12 was mixed with a polyoxyethylene nonionic surfactant (Brij C12E10). Relatively increasing the amount of the latter leads to a decrease in the relaxation time of the 80C12 solution. Correlatively, electrochemical experiments with a rotating disk electrode show a transition of the mass transport rate, which deviates from the classical Newtonian behavior in the same velocity domain. This result generalizes what has been already observed with solutions of linear polymers of high molecular weight and wormlike micelles based on surfactants subjected to elongational deformations. Moreover, the critical times derived from rheological and electrochemical experiments display the same trend.

Anionic polymerization of p-(2,2′-diphenylethyl)styrene and applications to graft copolymers

Well-controlled anionic polymerization of an initiator-functionalized monomer, p-(2,2′-diphenylethyl)styrene (DPES), was achieved for the first time. The polymerization was performed in a mixed solvent of cyclohexane and tetrahydrofuran (THF) at 40 °C with n-BuLi as initiator. When the volume ratio of cyclohexane to THF was 20, the anionic polymerization of DPES showed living polymerization characteristics, and well-defined block copolymer PDPES-b-PS was successfully synthesized. Furthermore, radical polymerization of methyl methacrylate in the presence of PDPES effectively afforded a graft copolymer composed of a polystyrene backbone and poly(methyl methacrylate) branches. The designation of analogous monomers and polymers was of great significance to synthesize a variety of sophisticated copolymer and functionalize polymer materials.

Dynamic Mechanical Properties of Networks of Wormlike Micelles Formed by Self-Assembled Comblike Amphiphilic Copolyelectrolytes

The rheological properties of viscoelastic aqueous solutions of wormlike micelles formed by the self-assembly of comblike copolyelectrolytes have been investigated by flow and dynamic measurements. The comblike polymers consisted of a polystyrene backbone grafted with a fixed amount of pendant N,N-dimethyl quaternary ammonium alkyl groups of various lengths ranging from C12 up to C18. Upon increasing concentration, the increase in size of the wormlike micelles and their branching results in the formation of a system spanning network through a percolation process at a critical concentration that decreases when salt is added or when the temperature is decreased. In this manner transient gels are formed with a viscoelastic relaxation time that does not depend on the polymer concentration or on the ionic strength, but their elastic modulus increases with increasing polymer or salt concentration. When the size of the alkyl groups is increased from C12 to C16, the relaxation time increases very strongly, but th...

Functionalization of emissive conjugated polymer nanoparticles by coprecipitation: consequences for particle photophysics and colloidal properties

The functionalization of polyfluorene (PFO) nanoparticles by coprecipitation of the conjugated polymer with an amphiphilic comb polymer, consisting of a hydrophobic polystyrene backbone with hydrophilic, carboxylic acid-terminated polyethylene oxide side-chains (PS-PEG-COOH), is investigated. The comb polymer affects the properties of the formed hybrid nanoparticles. Non-functionalized particles are typically larger (28 nm) than functionalized ones (20 nm); peak molar extinction coefficients are found to differ in a similar trend. Zeta potentials are negative, consistent with negative surface charge on PFO particles due to chemical defect formation, with additional charge on functionalized particles due to the pendant carboxylic acid groups. Emission quantum yields of functionalized particles are typically larger, consistent with lower efficiency of energy transfer to quenchers in smaller particles and weaker PFO interchain interactions due to chain dilution. The trend in per-particle fluorescence brightness values, as confirmed by single particle fluorescence imaging, reflects the nanoparticle extinction coefficients. Photostability studies on aqueous dispersions of hybrid particles indicate mild photobrightening under continuous illumination while PFO particles exhibit slow exponential emission decay. Functionalized particles are also resistant to aggregation during exposure to adenocarcinoma cells. Generally, the hybrid particles exhibit more favorable time-, pH- and medium-dependent stabilities, likely due to steric and electrostatic stabilization by PEG-carboxylic acid functionalities. Overall, the functionalized particles exhibit attractive properties: Reasonably small size, tight size distribution, high absorption cross section, radiative rate and emission quantum yield, excellent brightness and photostability, and good colloidal stability.

Fluorescent Polystyrene Microbeads as Invisible Security Ink and Optical Vapor Sensor for 4-Nitrotoluene

Color-tunable solid-state emitting polystyrene (PS) microbeads were developed by dispersion polymerization, which showed excellent fluorescent security ink characteristics along with sensitive detection of vapors of nitro aromatics like 4-nitro toluene (4-NT). The fluorophores pyrene and perylenebisimide were incorporated into the PS backbone as acrylate monomer and acrylate cross-linker, respectively. Solid state quantum yields of 94 and 20% were observed for the pyrene and perylenebisimide, respectively, in the PS/Py and PS/PBI polymers. The morphology and solid state fluorescence was measured by SEM, fluorescence microscopy, and absorbance and fluorescence spectroscopy techniques. The ethanol dispersion of the polymer could be used directly as a fluorescent security "invisible" ink, which became visible only under ultraviolet light. The color of the ink could be tuned depending on the amounts of the pyrene and perylenebisimide incorporated with blue and orange-green for pyrene alone or perylenebisimide alone beads respectively and various shades in between including pure white for beads incorporating both the fluorophores. More than 80% quenching of pyrene emission was observed upon exposure of the polymer in the form of powder or as spin-coated films to the vapors of 4-NT while the emission of perylenebisimide was unaffected. The limit of detection was estimated at 10(-5) moles (2.7 ppm) of 4-NT vapors. The ease of synthesis of the material along with its invisible ink characteristics and nitro aromatic vapor detection opens up new opportunities for exploring the application of these PS-based materials as optical sensors and fluorescent ink for security purposes.

Polymer-Based Ruthenium(II) Polypyridyl Chromophores on TiO2 for Solar Energy Conversion.

A polychromophoric light-harvesting assembly featuring a polystyrene (PS) backbone with ionic carboxylate-functionalized Ru(II) polypyridyl complexes as pendant groups (PS-Ru-A) was synthesized and successfully anchored onto mesoporous structured TiO2 films (TiO2 //PS-Ru-A). Studies of the resulting TiO2 //PS-Ru-A films carried out by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) confirmed that the ionic carboxylated Ru(II) complexes from PS-Ru-A led to the surface immobilization on the TiO2 film. Monochromatic light photocurrent spectroscopy (IPCE) and white light (AM1.5G) current-voltage studies of dye-sensitized solar cells using the TiO2 //PS-Ru-A photoanode give rise to modest photocurrent and white light efficiency (24 % peak IPCE and 0.33 % PCE, respectively). The photostability of surface-bound TiO2 //PS-Ru-A films was tested and compared to a monomeric Ru(II) complex (TiO2 //Ru-A), showing an enhancement of ∼14 % in the photostability of PS-Ru-A. Transient absorption measurements reveal that electron injection from surface-bound pendants occurs on the picosecond time scale, similar to TiO2 //Ru-A, while time-resolved emission measurements reveal delayed electron injection occurring in TiO2 //PS-Ru-A on the nanosecond time scale, underscoring energy transport from unbound to surface-bound complexes. Additionally, charge recombination is delayed in PS-Ru-A, pointing towards intra-assembly hole transport to complexes away from the surface. Molecular dynamics simulations of PS-Ru-A in fluid solution indicate that a majority of the pendant Ru(II) complexes lie within 10-20 Å of each other, facilitating efficient energy- and charge transport among the pendant complexes.