Helical Nanofibrils of Block Copolymer for High-Performance Ammonia Sensors

Abstract

Conjugated polymers with a helical structure have been in rapid development in recent years because of their potential applications in chemical and biological sensors. We demonstrate the fabrication and characterization of helical nanofibrils of block copolymer poly(4-iso-cyano-benzoic acid 5-(2-dimethylamino-ethoxy)-2-nitro-benzylester)- b-poly(3-hexylthiophene) (PPI(-DMAENBA)- b-P3HT) via a transfer-etching method. The density and lateral length of nanofibrils can be facilely controlled by regulating the process conditions, which, in turn, directly determine the electronic property. Organic field effect transistors based on helical nanofibrils were successfully fabricated with the highest mobility of 9.1 × 10 cm/(V s), an on/off ratio of 3.4 × 10, and high bias stability. The helical nanofibrils were proved to be beneficial for obtaining a highly sensitive and selective chemical sensor. And, the transistor based on helical nanofibrils exhibits a relative response of 28.6% to 100 ppb ammonia, which is even much higher than the responses to 1 ppm ammonia for homo poly(3-hexylthiophene) nanofibrils (7%) and block copolymer nanofibrils without helical structure (0.9%). The combination of helical structure with nanofibrils may provide a new strategy to fabricate high-performance chemical sensors suitable for use in environmental monitoring, industrial and agricultural production, health care, and foodsafety.

A One‐Pot Polymerization for Concurrently Inducing Predominant Helicity in Optically Inactive Helical Polymer and Constructing Graphene‐Based Chiral Hybrid Foams

“…Chiral helical polymers have attracted much interest due to their intriguing helical structures and chiral amplification effect . They demonstrate substantial potential applications in chiral‐related fields including asymmetric catalysis, chiral recognition/separation, enantio‐selective release, enantio‐selective crystallization, etc.…”

“…The eventually obtained chiral hybrid foams demonstrate advantages of porous structure, chirality, and reversible borate functional groups. The established preparation strategy promises a potent platform for conveniently constructing advanced chiral polymeric materials and even chiral hybrids starting from achiral monomers.Chiral helical polymers have attracted much interest due to their intriguing helical structures [1][2][3][4][5] and chiral amplification effect. [6,7] They demonstrate substantial potential applications [8] in chiral-related fields including asymmetric catalysis, [9] chiral recognition/separation, [10] enantio-selective release, [11] Macromol.…”

Advancements in Microfabricated Gas Sensors and Microanalytical Tools for the Sensitive and Selective Detection of Odors

“…Poly(3-hexylthiophene) (P3HT) is one of the most investigated OSC polymers used for gas sensing applications, showing high sensitivities at a few ppm (<10 ppm) and ultrafast response and recovery times (i.e., 1–2 s) [ 142 ]. Besides, recent studies show other OSCs in the form of nanocomposites with even higher sensitivities, detection limits in the ppb range (e.g., 100 ppb), and also fast responses (e.g., 3–7 s) [ 144 ]. In conclusion, one of the main advantages of polymeric materials (i.e., CP, IP, and OSCs) is that they can be easily miniaturized into micro- or nanostructures, by employing new micromachining techniques, such as electrochemical deposition [ 139 ], drop casting, screen printing [ 145 ], soft lithography [ 132 ], micromolding [ 135 ], dip- or spin coating [ 96 ], which have enabled to deploy micro- and nanofilms onto target substrates.…”

Stability of Polythiophene-Based Transistors upon Bending for Gas Sensing Applications

“…It is worth noting that most recently developed polythiophene-based TFTs as gas sensors still use hard substrates (e.g. Si and glass) [11][12][13][14][15][16][17][18][19][20][21][22][23][24] and rarely study performance upon bending or stretching [25]. This research will be the basis for future studies on flexible polythiophene-based FETs as gas sensors.…”