Oligomeric Compatibilizers for Control of phase Separation in Conjugated Polymer Blend Films

Abstract

Control over phase separation and morphology is critical to optimal function in polymer optoelectronic devices. Here, two fully conjugated oligomeric compatibilizers are introduced, and their effect on the phase separation of blends of poly(9,9′-dioctylfluorene-co-benzothiadiazole) (F8BT) with poly(9,9′-dioctylfluorene-co-bis-N,N′-(4,butylphenyl)bis-N,N′-phenyl-1,4-phenylenediamine) (PFB) are reported. AFM and STXM analysis demonstrate that the addition of compatibilizer altered the size and relative composition of phaseseparated domains formed during spin-casting. Small structural differences between the two compatibilizers brought about significantly different morphological changes to the blends, suggesting that further development of compatibilizer structure could enable enhanced control toward desired blend film morphologies.

High-Contrast Visualization and Differentiation of Microphase Separation in Polymer Blends by Fluorescent AIE Probes

“…To meet the application requirements in various fields, blending has been commonly used in polymer technology to generate new materials by simply mixing two or more polymers together. The resulting blends generally possess more desirable structural and physical characteristics in the solid state than those of individual components. , Nevertheless, the vast majority of polymer blends are immiscible and will easily and inevitably undergo phase separation process. , The phase-separated structures greatly affect the macroscopic properties, such as toughness, processability, transparency, chemical and weather resistance, thermal stability, flowability, etc., of a material and have strong impact on the performance of the corresponding products. , Especially for polymer blend films used in optoelectronic devices, the morphology and domain size of the microphase separation have a direct effect on their electrical and mechanical properties and hence the device performances. − Therefore, it is of considerable academic and industrial significance to detect the phase-separated structure in a polymer blend, so as to understand the underlying morphology–performance relationship and ultimately to realize a control on the performance of immiscible polymer mixtures by manipulating their phase separation.…”

Synthesis, Purification, and Characterization of Well-Defined All-Conjugated Diblock Copolymers PF8TBT-b-P3HT

“…Here we present the synthesis, purification, and characterization of all-conjugated block copolymers comprising PF8TBT and P3HT. With PF8TBT/P3HT blends among the most efficient all-polymer solar cells, , well-defined block copolymers PF8TBT- b -P3HT of substantial molecular weight are materials that are likely to enable further improvements in OPV performance via enhanced morphology control, either in the form of pristine components or as compatibilizers , in ternary blends. We use Suzuki step-growth polycondensation for the synthesis of PF8TBT followed by the in situ addition of various chain lengths of monobrominated P3HT-Br.…”

Morphology stabilization strategies for small-molecule bulk heterojunction photovoltaics

“…a block co-polymer), which is included in the active layer during device fabrication. [31][32][33][34][35][36] Donor-acceptor block-copolymers can be envisioned as a single active component for truly thermodynamically stable polymer BHJs. [37][38][39][40] Despite the interest in developing strategies for stabilization of polymer-based devices, few reports have addressed morphological stability in small-molecule BHJs even though this is reasonably a greater challenge, due to the relatively high crystallinity in small molecule semiconductors and the absence of polymer entanglement, which leads to negligible mixing between the donor and acceptor.…”