Polymer blend

About: Polymer blend is a research topic. Over the lifetime, 18474 publications have been published within this topic receiving 437183 citations. The topic is also known as: polymer mixture & Polymerblend 或者 Polyblend.

Shape-Dependent Localization of Carbon Nanotubes and Carbon Black in an Immiscible Polymer Blend during Melt Mixing

Abstract: In melt mixed multiphase polymer blends, the mechanisms determining the spatial distribution and localization of solid particles smaller than the blend domain sizes are still not completely understood. From theoretical considerations of a previous paper of one of the authors, it was derived that the transfer dynamics as well as the stability of different solid fillers at the blend interface reveal a strong dependence on the particle’s aspect ratio. Low interfacial stabilities and high transfer speeds between the blend phases can be deduced for fillers with very high aspect ratios, entitled as the “Slim-Fast Mechanism” (SFM). The SFM appears suitable to explain in retrospect important features of several previous studies that address the localization of differently shaped nanoscaled particles in polymer blends. The SFM was evaluated by investigating the simultaneous transfer of multiwalled carbon nanotubes (MWCNTs) and carbon black (CB) from a poly(styrene acrylonitrile) (SAN) precompound into the thermody...

Highly efficient charge-carrier generation and collection in polymer/polymer blend solar cells with a power conversion efficiency of 5.7%

Abstract: A polymer/polymer blend solar cell with an external quantum efficiency approaching 60% and the best power conversion efficiency of 5.73% is fabricated. The efficient charge-carrier generation and collection, comparable to those of polymer/fullerene solar cells, are found to be the main reasons for the superior device performance.

Charge transfer in photovoltaics consisting of interpenetrating networks of conjugated polymer and TiO2 nanoparticles

Abstract: We study the effect of blended and layered titanium dioxide (TiO2) nanoparticles on charge transfer processes in conjugated polymer photovoltaics. A two order of magnitude increase in photoconductivity and sharp saturation is observed for layered versus blended structures, independent of the cathode work function. Using electrodes with similar work functions, we observe low dark currents and open circuit voltages of 0.7 V when a TiO2 nanoparticle layer is self-assembled onto the indium–tin–oxide electrode. Our results for the layered morphologies are consistent with charge collection by exciton diffusion and dissociation at the TiO2 interface.

Efficient Polythiophene/Polyfluorene Copolymer Bulk Heterojunction Photovoltaic Devices: Device Physics and Annealing Effects†

Abstract: Here the influence of annealing on the operational efficiency of all-polymer solar cells based on blends of the polymers poly(3-hexylthiophene) (P3HT) and poly((9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(3-hexylthiophen-5-yl)-2,1,3-benzothiadiazole]-2′,2″-diyl) (F8TBT) is investigated. Annealing of completed devices is found to result in an increase in power conversion efficiency from 0.14 to 1.20%, while annealing of films prior to top electrode deposition increases device efficiency to only 0.19% due to a lowering of the open-circuit voltage and short-circuit current. By studying the dependence of photocurrent on intensity and effective applied bias, annealing is found to increase charge generation efficiency through an increase in the efficiency of the separation of bound electron-hole pairs following charge transfer. However, unlike many other all-polymer blends, this increase in charge separation efficiency is not only due to an increase in the degree of phase separation that assists in the spatial separation of electron-hole pairs, but also due to an order of magnitude increase in the hole mobility of the P3HT phase. The increase in hole mobility with annealing is attributed to the ordering of P3HT chains evidenced by the red-shifting of P3HT optical absorption in the blend. We also use X-ray photoelectron spectroscopy (XPS) to study the influence of annealing protocol on film interface composition. Surprisingly both top and bottom electrode/blend interfaces are enriched with P3HT, with the blend/top electrode interface consisting of more than 95% P3HT for as-spun films and films annealed without a top electrode. Films annealed following top electrode deposition, however, show an increase in F8TBT composition to ∼15%. The implications of interfacial composition and the origin of open-circuit voltage in these devices are also discussed.