Photocrosslinkable π-conjugated cruciform molecules for electronic/optoelectronic applications

Abstract

The development of organic field-effect transistors (OFETs) and organic photovoltaic cells (OPV) has seen much progress using solution-processable organic semiconductors, which can combine high charge transport mobility, stability and patternability. In this work, we report on the design and synthesis of a new type of photopatternable π-conjugated cruciform molecule. These molecules are capable of photopatterning by virtue of photopolymerization of the reactive end-groups (pentadien or acrylate). Their solubility is very good for solution processing. Transistor devices using these molecules provided a maximum field-effect mobility of 3.7 × 10 −3 cm 2 V −1 s −1 as well as a high current on/off ratio. Remarkably, it was found that their charge carrier mobilities were well-maintained, even after the photocrosslinking process.

Improved nanoindentation and microwave shielding properties of modified MWCNT reinforced polyurethane composites

“…In another study by Zunfeng et al, 25 the microwave absorption properties in the 2-18 GHz range with 0-25 wt% SWCNT loading were investigated and the maximum EMI shielding effectiveness of 22 dB at 5 wt% loading was reported. Hoang 26 reported the EMI shielding effectiveness of MWCNTs-polyurethane composite lms in the 8-12 GHz frequency range and the EMI shielding effectiveness of 20 dB was reported with 22 wt% MWCNT loading. It is observed from the above studies on CNT-PU composites that shielding effectiveness varies from 17 to 22 dB at very high loading.…”

Electrical conductivity and electromagnetic interference shielding effectiveness of nano‐structured carbon assisted poly(methyl methacrylate) nanocomposites

“…Several previous studies on desired properties such as electrical and EMI shielding behavior are worth discussing in the context of our reported work (Table 2). [ 3,14,24,39,42,53‐64 ] First, our results cover consumer demand that is low percolation threshold, high electrical conductivity, and excellent EMI shielding efficiency with low K‐CB loading. It is important to emphasize that the previous studies were in the case of conductive filler where such fillers bear severe limitations such as very high cost, high manufacturing cost, and processing difficulties.…”

“…In general, the electrical conductivity of the polymeric materials depends on the material composition, processing strategy, material intrinsic conductivity, and dispersion of conductive filler particles in the polymer matrix. [ 4,39 ] Figure 7A shows the variation of DC conductivity of PMMA/K‐CB nanocomposites having K‐CB filler content (1‐10 wt%) at 25°C. The DC conductivity of PMMA nanocomposites increases from 1.5 × 10 −12 to 2.2 × 10 −3 S/cm with the incorporation of K‐CB filler from 0 to 10 wt%.…”

Preparation of Naphthalene Dianhydride Bithiophene Copolymers by Direct Arylation Polycondensation and the Latent Pigment Approach

“…The most common solution to this problem is the use of orthogonal solvents, which is limited to few cases when the two or more materials to be processed have very different solubility. In order to obtain layered heterostructures via printing approaches alone, chemical or thermal crosslinking approaches were developed . Albeit successful, this approach is somewhat synthetically intensive and requires the introduction of additives or reactive functionalities that may disturb structure formation and limit the charge carrier mobility of the materials .…”

“…In order to obtain layered heterostructures via printing approaches alone, chemical or thermal crosslinking approaches were developed . Albeit successful, this approach is somewhat synthetically intensive and requires the introduction of additives or reactive functionalities that may disturb structure formation and limit the charge carrier mobility of the materials . An alternative and increasingly popular solution is the introduction of solubilizing chains that can be removed via thermal treatment after deposition.…”