scholarly journals Selective Ammonia-Sensing Platforms Based on a Solution-Processed Film of Poly(3-Hexylthiophene) and p-Doping Tris(Pentafluorophenyl)Borane

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 128 ◽  
Author(s):  
Alem Araya Meresa ◽  
Felix Sunjoo Kim

Here, we fabricate ammonia sensors based on organic transistors by using poly(3-hexylthiophene) (P3HT) blended with tris(pentafluorophenyl)borane (TPFB) as an active layer. As TPFB is an efficient p-type dopant for P3HT, the current level of the blend films can be easily modulated by controlling the blend ratio. The devices exhibit significantly increased on-state and off-state current levels owing to the ohmic current originated from the large number of charge carriers when the active polymer layer contains TPFB with concentrations up to 20 wt % (P3HT:TPFB = 8:2). The current is decreased at 40 wt % of TPFB (P3HT:TPFB = 6:4). The P3HT:TPFB blend with a weight ratio of 9:1 exhibits the highest sensing performances for various concentrations of ammonia. The device exhibits an increased percentage current response compared to that of a pristine P3HT device. The current response of the P3HT:TPFB (9:1) device at 100 ppm of ammonia is as high as 65.8%, 3.2 times that of the pristine P3HT (20.3%). Furthermore, the sensor based on the blend exhibits a remarkable selectivity to ammonia with respect to acetone, methanol, and dichloromethane, owing to the strong interaction between the Lewis acid (TPFB) and Lewis base (ammonia).

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 317 ◽  
Author(s):  
Haihong Yin ◽  
Changqing Song ◽  
Zhiliang Wang ◽  
Haibao Shao ◽  
Yi Li ◽  
...  

VO2(B), VO2(M), and V2O5 are the most famous compounds in the vanadium oxide family. Here, their gas-sensing properties were investigated and compared. VO2(B) nanoflakes were first self-assembled via a hydrothermal method, and then VO2(M) and V2O5 nanoflakes were obtained after a heat-phase transformation in nitrogen and air, respectively. Their microstructures were evaluated using X-ray diffraction and scanning and transmission electron microscopies, respectively. Gas sensing measurements indicated that VO2(M) nanoflakes were gas-insensitive, while both VO2(B) and V2O5 nanoflakes were highly selective to ammonia at room temperature. As ammonia sensors, both VO2(B) and V2O5 nanoflakes showed abnormal p-type sensing characteristics, although vanadium oxides are generally considered as n-type semiconductors. Moreover, V2O5 nanoflakes exhibited superior ammonia sensing performance compared to VO2(B) nanoflakes, with one order of magnitude higher sensitivity, a shorter response time of 14–22 s, and a shorter recovery time of 14–20 s. These characteristics showed the excellent potential of V2O5 nanostructures as ammonia sensors.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 992
Author(s):  
Suchitha Devadas ◽  
Saja M. Nabat Al-Ajrash ◽  
Donald A. Klosterman ◽  
Kenya M. Crosson ◽  
Garry S. Crosson ◽  
...  

Lignin macromolecules are potential precursor materials for producing electrospun nanofibers for composite applications. However, little is known about the effect of lignin type and blend ratios with synthetic polymers. This study analyzed blends of poly(acrylonitrile-co-methyl acrylate) (PAN-MA) with two types of commercially available lignin, low sulfonate (LSL) and alkali, kraft lignin (AL), in DMF solvent. The electrospinning and polymer blend solution conditions were optimized to produce thermally stable, smooth lignin-based nanofibers with total polymer content of up to 20 wt % in solution and a 50/50 blend weight ratio. Microscopy studies revealed that AL blends possess good solubility, miscibility, and dispersibility compared to LSL blends. Despite the lignin content or type, rheological studies demonstrated that PAN-MA concentration in solution dictated the blend’s viscosity. Smooth electrospun nanofibers were fabricated using AL depending upon the total polymer content and blend ratio. AL’s addition to PAN-MA did not affect the glass transition or degradation temperatures of the nanofibers compared to neat PAN-MA. We confirmed the presence of each lignin type within PAN-MA nanofibers through infrared spectroscopy. PAN-MA/AL nanofibers possessed similar morphological and thermal properties as PAN-MA; thus, these lignin-based nanofibers can replace PAN in future applications, including production of carbon fibers and supercapacitors.


Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 939
Author(s):  
Rosario Schiano Lo Moriello ◽  
Davide Ruggiero ◽  
Leopoldo Angrisani ◽  
Enzo Caputo ◽  
Francesco de Pandi ◽  
...  

Thanks to their peculiar features, organic transistors are proving to be a valuable alternative to traditional semiconducting devices in several application fields; however, before releasing their exploitation, simulating their behaviour through adequate circuital models could be advisable during the design stage of electronic circuits and/or boards. Consequently, accurately extracting the parameter value of those models is fundamental to developing useful libraries for hardware design environments. To face the considered problem, the authors present a method based on successive application of Single- and Multi-Objective Evolutionary Algorithm for the optimal tuning of model parameters of organic transistors on thin film (OTFT). In particular, parameters are first roughly estimated to assure the best fit with the experimental transfer characteristics; the estimates are successively refined through the multi-objective strategy by also matching the values of the experimental mobility. The performance of the method has been assessed by estimating the parameters value of both P-type and N-type OTFTs characterized by different values of channel lengths; the obtained results evidence that the proposed method can obtain suitable parameters values for all the considered channel lengths.


2012 ◽  
Vol 77 (12) ◽  
pp. 1723-1733 ◽  
Author(s):  
Jelena Djokic ◽  
Aleksandar Kojovic ◽  
Dusica Stojanovic ◽  
Aleksandar Marinkovic ◽  
Goran Vukovic ◽  
...  

Chitosan based films have found an increasing implementation in variety of topics among which as drug delivery carriers, in packaging industry and as water puritication filters. Therefore, in order to achieve mechanical integrity of such films while preserving processability and biocompatibility, chitosan based films are fabricated in forms of blends with polyethylene oxide (PEO). Nanoindentation study is undertaken in order to investigate nanomechanical properties and surface morphology of chitosan films in blends with various content of PEO. Results of differential scanning calorimetry, water uptake and nanoindentation revealed that films with 80/20 blend ratio of chitosan/PEO showed the optimal values of reduced modulus and hardness. It appears that the incorporation of synthetic PEO in chitosan films could lower the manufacturing cost while preserving the mechanical integrity of the films.


2020 ◽  
Vol 8 (43) ◽  
pp. 15368-15376
Author(s):  
Aniruddha Basu ◽  
Muhammad Rizwan Niazi ◽  
Alberto D. Scaccabarozzi ◽  
Hendrik Faber ◽  
Zuping Fei ◽  
...  

Blade-coating is used to fabricate high hole mobility organic transistors based on a p-doped small-molecule:polymer blend semiconductor.


2013 ◽  
Vol 377 ◽  
pp. 209-214
Author(s):  
Ling Shuang Wang ◽  
Shu Qin Yan ◽  
Ming Zhong Li

Stimulating cell proliferation is a challenge in the field of silk fibroin-based biomaterials. In this study, silk fibroin/hyaluronic acid blend films were prepared by a casting method using carbodiimide as a cross-linking agent. Carbodiimide induced silk fibroin to form Silk I crystal structure which was not affected by the presence of hyaluronic acid. The films showed high water resistance. In vitro, the performance of these films was assessed by seeding L929 cells. The results indicated that the silk fibroin/hyaluronic acid blend films with the blend ratio of 80/20 and 60/40 promoted cell proliferation compared with the pure silk fibroin or hyaluronic acid film. These results suggest that silk fibroin/hyaluronic acid blend films are water stable and cytocompatible materials which are expected to be useful in biomedical applications.


2013 ◽  
Vol 25 (25) ◽  
pp. 3500-3500
Author(s):  
Liqiang Li ◽  
Peng Gao ◽  
Martin Baumgarten ◽  
Klaus Müllen ◽  
Nan Lu ◽  
...  

2016 ◽  
Vol 4 (1) ◽  
pp. 162-168 ◽  
Author(s):  
F. X. Werkmeister ◽  
T. Koide ◽  
B. A. Nickel

Organic transistors detect the enzymatic breakdown of ureaviaammonia diffusion into the transistor through a semipermeable parylene-C membrane.


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