Crystallization Control of N,N'-Dioctyl Perylene Diimide by Amphiphilic Block Copolymers Containing poly(3-Hexylthiophene) and Polyethylene Glycol.

Xiaohui Yang,Demei Yu,Weili Li,Guanghao Lu,Jingning Cao,Fangwen Zha,Wanlong Lu,Hongkun Tian,Laju Bu,Chenyang Zhai

doi:10.3389/fchem.2021.699387

Abstract

The preparation of micron- to nanometer-sized functional materials with well-defined shapes and packing is a key process to their applications. There are many ways to control the crystal growth of organic semiconductors. Adding polymer additives has been proven a robust strategy to optimize semiconductor crystal structure and the corresponding optoelectronic properties. We have found that poly(3-hexylthiophene) (P3HT) can effectively regulate the crystallization behavior of N,N′-dioctyl perylene diimide (C8PDI). In this study, we combined P3HT and polyethylene glycol (PEG) to amphiphilic block copolymers and studied the crystallization modification effect of these block copolymers. It is found that the crystallization modification effect of the block copolymers is retained and gradually enhanced with P3HT content. The length of C8PDI crystals were well controlled from 2 to 0.4 μm, and the width from 210 to 35 nm. On the other hand, due to the water solubility of PEG block, crystalline PEG-b-P3HT/C8PDI micelles in water were successfully prepared, and this water phase colloid could be stable for more than 2 weeks, which provides a new way to prepare pollution-free aqueous organic semiconductor inks for printing electronic devices.

Highlights

The preparation of micron- and nanometer-sized functional materials with well-defined shapes and sizes has broad applications in catalysis, electronics, medicine and other fields
The product was purified by column chromatography and recycling preparative liquid chromatography. 1H nuclear magnetic resonance (NMR) spectroscopy shows the regioregularity of EP3HT is 90% (Supplementary Figure S1)
Their structures were characterized by 1H NMR and fourier transform infrared spectroscopy (FT-IR) spectroscopy (Supplementary Figure S6) and their molecular weights were measured by gel permeation chromatography (GPC)

Summary

INTRODUCTION

The preparation of micron- and nanometer-sized functional materials with well-defined shapes and sizes has broad applications in catalysis, electronics, medicine and other fields. Polymer additives can effectively control the orientation and morphology of organic semiconductor crystals (He et al, 2019). The morphology of crystal is usually controlled by changing the ratio of polymer to semiconductor, concentration, solvent and other conditions. Bu et al found that P3HT can control the crystallization behavior of the n-type semiconductor small molecule N,N′-dioctyl perylene diimide (C8PDI), making fibrillar C8PDI crystals (Bu et al, 2012). By adjusting the concentration of the block copolymer and the pH of the solution, a series of perylene derivative with different crystal morphologies can be obtained. We first explored the regulation effect of different block copolymers on C8PDI crystallization and found that the crystallization modification effect is retained and gradually enhanced as P3HT content increases, making the length and width of C8PDI crystals gradually decrease. We prepared stable crystalline P3HT-b-PEG/C8PDI micelles in water by extracting their micelles in toluene (Tol) with water, which provides a new way to prepare pollution-free aqueous organic semiconductor inks for printing electronic devices

RESULTS AND DISCUSSION

MATERIALS AND METHODS

Synthetic Procedures

CONCLUSION