共查询到20条相似文献，搜索用时 15 毫秒
1.
2.
Wei Zhi Wang Wei Feng Li Xiao Yong Pan Chang Ming Li Lain‐Jong Li Yu Guang Mu John A Rogers Mary B. Chan‐Park 《Advanced functional materials》2011,21(9):1643-1651
Polymers which enrich semiconducting single‐walled carbon nanotubes (SWNTs) and are also removable after enrichment are highly desirable for achieving high‐performance field‐effect transistors (FETs). We have designed and synthesized a new class of alternating copolymers containing main‐chain fluorene and hydrofluoric acid (HF) degradable disilane for sorting and preferentially suspending semiconducting nanotube species. The results of optical absorbance, photoluminescence emission, and resonant Raman scattering show that poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐alt‐co‐1,1,2,2‐tetramethyl‐disilane] preferentially suspends semiconducting nanotubes with larger chiral angle (25°–28°) and larger diameter (1.03 nm–1.17 nm) (specifically (8,7), (9,7) and (9,8) species) present in HiPCO nanotube samples. Computer simulation shows that P1 preferentially interacts with (8,7) (semiconducting) over (7,7) (metallic) species, confirming that P1 selects larger diameter, larger chiral angle semiconducting tubes. P1 wrapped on the surface of SWNTs is easily washed off through degradation of the disilane bond of the alternating polymer main chain in HF, yielding “clean” purified SWNTs. We have applied the semiconducting species enriched SWNTs to prepare solution‐processed FET devices with random nanotube network active channels. The devices exhibit stable p‐type semiconductor behavior in air with very promising characteristics. The on/off current ratio reaches up to 15 000, with on‐current level of around 10 μA and estimated hole mobility of 5.2 cm2 V?1 s?1. 相似文献
3.
Jianxin Geng Byung‐Seon Kong Seung Bo Yang Sang Cheon Youn Sohyun Park Taiha Joo Hee‐Tae Jung 《Advanced functional materials》2008,18(18):2659-2665
Poly(3‐hexylthiophene) (P3HT) hybrids with single‐walled carbon nanotubes (SWNTs) were prepared using a series of SWNTs with various defect contents on their surfaces. The hybrids were synthesized by exploiting the π–π interaction between P3HT and the SWNTs, resulting in efficient dispersion of the carbon nanotubes in the P3HT solution. UV‐visible and photoluminescence (PL) spectra showed that the carbon nanotubes quench the PL of P3HT in the hybrids, indicating that electron transfer occurs from photo‐excited P3HT to the SWNTs. This electron transfer from P3HT to carbon nanotubes was disrupted by the presence of defects on the SWNT surfaces. However, the PL lifetime of P3HT in the hybrids was found to be the same as that of pure P3HT in solution, indicating the formation of a ground‐state non‐fluorescent complex of P3HT/SWNTs. 相似文献
4.
Yahui Li Miaomiao Zheng Jian Yao Wenbin Gong Yijun Li Jianshi Tang Shun Feng Ruyue Han Qicheng Sui Song Qiu Lixing Kang Hehua Jin Dongming Sun Qingwen Li 《Advanced functional materials》2022,32(1):2107119
Monochiral single-walled carbon nanotubes (SWCNTs) are promising materials with potential applications in 3D integrated circuits and optoelectronic hybrid circuits. However, the purity and device performance of monochiral SWCNTs are still far lower than expected. Here, the authors demonstrate that specific monochiral SWCNTs can be wrapped by conjugated polymers containing pyridine units, and the supramolecular assemblies show surprising suspension stability even after high-intensity ultracentrifugation. Additionally, two novel methods are developed, namely, enhanced ultracentrifugation (E-UCG) and stepwise extraction processing (STEP), which successfully achieve isolation of (10,8) and (12,5) SWCNTs with respective diameters of 1.24 and 1.2 nm at high monochiral purity (92.3% and 95.6%). Their S11 absorption and fluorescence emission peaks are both at ≈1.5 µm (optical telecommunications C-band). Both micro- and nanoscale field-effect transistor (FET) devices can be fabricated from the as-isolated (10,8) SWCNTs, and these FETs exhibit excellent electrical performance and a high semiconducting purity of up to 99.94%. 相似文献
5.
A general strategy to disperse and functionalize pristine carbon nanotubes in a single‐step process is developed using conjugated block copolymers. The conjugated block copolymer contains two blocks: a conjugated polymer block of poly(3‐hexylthiophene), and a functional non‐conjugated block with tunable composition. When the pristine carbon nanotubes are sonicated with the conjugated block copolymers, the poly(3‐hexylthiophene) blocks bind to the surface of de‐bundled carbon nanotubes through non‐covalent π–π interactions, stabilizing the carbon nanotube dispersion, while the functional blocks locate at the outer surface of carbon nanotubes, rendering the carbon nanotubes with desired functionality. In this paper, conjugated block copolymers of poly(3‐hexylthiophene)‐b‐poly(methyl methacrylate), poly(3‐hexylthiophene)‐b‐poly(acrylic acid), and poly(3‐hexylthiophene)‐b‐poly(poly(ethylene glycol) acrylate) are used to demonstrate this general strategy. 相似文献
6.
Chan Kyu Kwak Dai Geun Kim Tae Hyeon Kim Chang‐Soo Lee Minjung Lee Taek Seung Lee 《Advanced functional materials》2010,20(22):3847-3855
Poly{[2,5‐bis(3‐sulfonatobutoxy)‐1,4‐phenylene sodium salt]‐alt‐(1,4‐phenylene)}, which is an anionically charged, water‐soluble poly(para‐phenylene) derivative with aldehyde groups at both chain ends, is prepared via the Suzuki coupling reaction in order to develop a FRET energy donor, while simultaneously dual‐fluorescence‐patterning the protein. Regardless of the end‐capping, the synthesized polymer exhibits a good solubility in water with an absorption maximum at 338 nm and a photoluminescence maximum at 417 nm, similar to those of the the end‐capped polymer. The emission spectrum of the polymer overlaps the absorption spectrum of fluorescein, and therefore, the polymer can be used as an energy donor with fluorescein as the energy acceptor in the FRET mechanism. This polymer design not only takes advantage of the introduction of biotin at both chain ends (through a reaction with the aldehyde end groups) to realize the facile interaction with streptavidin, but also brings into play the electrostatic features of the anionic sulfonate groups to fabricate an electrostatic self‐assembly with polycation for the pattern substrate. The micropattern of fluorescein‐labeled streptavidin is fabricated on the polymer‐coated substrate through micro‐contact printing using a polydimethylsiloxane mold. As a result, the polymer substrate exhibits a dual fluorescence micropattern, which results from the blue emission color from the energy donor and the FRET‐amplified green emission from the energy acceptor. The high‐resolution patterning is carried out for the application of multiplexing by simultaneously imaging the patterned green‐emitting fluorescein by FRET and the surrounding blue‐emitting polymer according to an optical detection scheme. 相似文献
7.
Nicole A. Rice William J. Bodnaryk Brendan Mirka Owen A. Melville Alex Adronov Benoît H. Lessard 《Advanced Electronic Materials》2019,5(1)
The realization of organic thin film transistors (OTFTs) with performances that support low‐cost and large‐area fabrication remains an important and challenging topic of investigation. The unique electrical properties of single‐walled carbon nanotubes (SWNTs) make them promising building blocks for next generation electronic devices. Significant advances in the enrichment of semiconducting SWNTs, particularly via π‐conjugated polymers for purification and dispersal, have allowed the preparation of high‐performance OTFTs on a small scale. The intimate interaction of the conjugated polymer with both SWNTs and the dielectric necessitates the investigation of a variety of conjugated polymer derivatives for device optimization. Here, the preparation of polymer–SWNT composites containing carbazole moieties, a monomer unit that has remained relatively overlooked for the dispersal of large‐diameter semiconducting SWNTs, is reported. This polymer selectively discriminates semiconducting SWNTs using a facile procedure. OTFTs prepared from these supramolecular complexes are ambipolar, and possess superior mobilities and on/off ratios compared to homo poly(fluorene) dispersions, with hole mobilities from random‐network devices reaching 21 cm2 V−1 s−1. Atomic force microscopy measurements suggest the poly(carbazole)–SWNT composites form more uniform thin films compared to the poly(fluorene) dispersion. Additionally, treating the silicon dioxide dielectric with octyltrichlorosilane is a simple and effective way to reduce operational hysteresis in SWNT OTFTs. 相似文献
8.
9.
Teddy Salim Hang‐Woo Lee Lydia Helena Wong Zhenan Bao Yeng Ming Lam 《Advanced functional materials》2016,26(1):51-65
The effects of the incorporation of semiconducting single‐walled nanotubes (sc‐SWNTs) with high purity on the bulk heterojunction (BHJ) organic solar cell (OSC) based on regioregular poly(3‐hexylthiophene‐2,5‐diyl):[6,6]‐phenyl‐C61‐butyric acid methyl ester (rr‐P3HT:PCBM) are reported for the first time. The sc‐SWNTs induce the organization of the polymer phase, which is evident from the increase in crystallite size, the red‐shifted absorption characteristics and the enhanced hole mobility. By incorporating sc‐SWNTs, OSC with a power conversion efficiency (PCE) as high as 4% can be achieved, which is ≈8% higher than our best control device. A novel application of sc‐SWNTs in improving the thermal stability of BHJ OSCs is also demonstrated. After heating at 150 °C for 9 h, it is observed that the thermal stability of rr‐P3HT:PCBM devices improves by more than fivefold with inclusion of sc‐SWNTs. The thermal stability enhancement is attributed to a more suppressed phase separation, as shown by the remarkable decrease in the formation of sizeable crystals, which in turn can be the outcome of a more controlled crystallization of the blend materials on the nanotubes. 相似文献
10.
Jui‐Fen Chang Michael C. Gwinner Mario Caironi Tomo Sakanoue Henning Sirringhaus 《Advanced functional materials》2010,20(17):2825-2832
Solution processing of polymer semiconductors provides a new paradigm for large‐area electronics manufacturing on flexible substrates, but it also severely restricts the realization of interesting advanced device architectures, such as lateral heterostructures with defined interfaces, which are easily accessible with inorganic materials using photolithography. This is because polymer semiconductors degrade, swell, or dissolve during conventional photoresist processing. Here a versatile, high‐resolution photolithographic method is demonstrated for patterning of polymer semiconductors and exemplify this with high‐performance p‐type and n‐type field‐effect transistors (FETs) in both bottom‐ and top‐gate architectures, as well as ambipolar light‐emitting field‐effect transistors (LEFETs), in which the recombination zone can be pinned at a photolithographically defined lateral heterojunction between two semiconducting polymers. The technique therefore enables the realization of a broad range of novel device architectures while retaining optimum materials performance. 相似文献
11.
Flow cytometry can provide detailed information about protein expression on cell surface and is, therefore, widely used in clinical testing. However, owing to the limited sensitivity of fluorescence signals, detection of low-expression cell surface markers is challenging. The present report describes a DNA-mediated, on-membrane assembly of conjugated polymer nanoparticles (Pdots) that amplifies fluorescence signal from surface markers for sensitive detection via flow cytometry. Single-stranded DNA (ssDNA)-conjugated antibodies are first bound to cell surface markers, from which ssDNA-modified Pdots are sequentially assembled using DNA hybridization. The use of DNA as a linker enables the distance-controlled assembly of Pdots to prevent fluorescence quenching, whereas their on-membrane sequential assembly allows amplification of the fluorescence signal without reducing binding ability of antibodies. Thus, two rounds of Pdot assembly achieve 31-fold amplification of the fluorescence signal from CD19 on Nalm-6 cells, which is 125-fold brighter than that obtained using the conventional fluorescent dye-based method. Moreover, the sequential assembly of 22 nm Pdots shows 24-fold higher fluorescence than one-step labeling with 81 nm Pdots, suggesting the advantage of the sequential assembly strategy in avoiding steric hindrance. The proposed method is expected to contribute to the sensitive detection of low-expression surface markers for early and accurate diagnosis. 相似文献
12.
Ting Lei Gregory Pitner Xiyuan Chen Guosong Hong Steve Park Pascal Hayoz Ralf Thomas Weitz Hon‐Sum Philip Wong Zhenan Bao 《Advanced Electronic Materials》2016,2(1)
The isolation of semiconducting single‐walled carbon nanotubes (sc‐SWNTs) with ideal diameter and high purity is highly desired for high‐performance electronic devices. However, current sorting methods for large‐diameter sc‐SWNTs suffer from either low purity (<99%) or long processing time (>20 h). Here, a backbone‐engineering strategy is reported for the polymer used for sorting to improve the purity of sorted sc‐SWNTs. Six diketopyrrolopyrrole (DPP)‐based conjugated polymers are used to systematically investigate their sorting ability for sc‐SWNTs. It is found that incorporation of more thiophenes building blocks in the repeating units of DPP polymer backbone leads to increased selectivity and yield for sc‐SWNTs. The DPP polymers can disperse sc‐SWNTs with 1.4–1.6 nm in diameter and high purity of 99.6% by a processing time as short as 1 h. Furthermore, a scalable film coating method named “solution shearing” is used to fabricate SWNT network thin‐film transistors (TFTs). The TFT devices exhibit both high mobilities over 50 cm2 V−1 s−1 and high on/off ratios over 105, which are among the highest performance for solution‐processed SWNT network TFTs. 相似文献
13.
14.
Lifeng Huang Naresh Eedugurala Anthony Benasco Song Zhang Kevin S. Mayer Daniel J. Adams Benjamin Fowler Molly M. Lockart Mohammad Saghayezhian Hamas Tahir Eric R. King Sarah Morgan Michael K. Bowman Xiaodan Gu Jason D. Azoulay 《Advanced functional materials》2020,30(24)
Conductive polymers largely derive their electronic functionality from chemical doping, processes by which redox and charge‐transfer reactions form mobile carriers. While decades of research have demonstrated fundamentally new technologies that merge the unique functionality of these materials with the chemical versatility of macromolecules, doping and the resultant material properties are not ideal for many applications. Here, it is demonstrated that open‐shell conjugated polymers comprised of alternating cyclopentadithiophene and thiadiazoloquinoxaline units can achieve high electrical conductivities in their native “undoped” form. Spectroscopic, electrochemical, electron paramagnetic resonance, and magnetic susceptibility measurements demonstrate that this donor–acceptor architecture promotes very narrow bandgaps, strong electronic correlations, high‐spin ground states, and long‐range π‐delocalization. A comparative study of structural variants and processing methodologies demonstrates that the conductivity can be tuned up to 8.18 S cm?1. This exceeds other neutral narrow bandgap conjugated polymers, many doped polymers, radical conductors, and is comparable to commercial grades of poly(styrene‐sulfonate)‐doped poly(3,4‐ethylenedioxythiophene). X‐ray and morphological studies trace the high conductivity to rigid backbone conformations emanating from strong π‐interactions and long‐range ordered structures formed through self‐organization that lead to a network of delocalized open‐shell sites in electronic communication. The results offer a new platform for the transport of charge in molecular systems. 相似文献
15.
16.
Hande E. Cingil Emre B. Boz Martien A. Cohen Stuart Joris Sprakel 《Advanced functional materials》2016,26(9):1420-1427
Attractive electrostatic forces between polymers can be exploited to create well‐defined and responsive nanoscale structures. In the process of charge‐driven coassembly, the polymers involved undergo subtle conformational changes. However, ascertaining these conformational transitions, and relating this to the nanostructures that are formed, has remained elusive to date. Here it is shown how the force‐optical response of tailored mechanochromic polymers can be used to detect structural transitions that occur at the nanoscale during assembly. It is shown that at low‐charge stoichiometry, electrostatic binding causes individual macromolecules to stretch and stiffen. Remarkably, at stoichiometries close to full charge compensation a gradual transition from single molecular complexes to multimolecular micelles is observed. Moreover, the same macromolecular sensors reveal how the assembly pathways are fully reversible as the binding strength is weakened. These results highlight how mechanochromic polymer sensors can be used to detect the molecular transitions occur during supramolecular structure formation with high precision. 相似文献
17.
Jihong Kim Dongyoon Khim Kang‐Jun Baeg Won‐Tae Park Seung‐Hoon Lee Minji Kang Yong‐Young Noh Dong‐Yu Kim 《Advanced functional materials》2016,26(43):7886-7894
A specific design for solution‐processed doping of active semiconducting materials would be a powerful strategy in order to improve device performance in flexible and/or printed electronics. Tetrabutylammonium fluoride and tetrabutylammonium hydroxide contain Lewis base anions, F? and OH?, respectively, which are considered as organic dopants for efficient and cost‐effective n‐doping processes both in n‐type organic and nanocarbon‐based semiconductors, such as poly[[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)] (P(NDI2OD‐T2)) and selectively dispersed semiconducting single‐walled carbon nanotubes by π‐conjugated polymers. The dramatic enhancement of electron transport properties in field‐effect transistors is confirmed by the effective electron transfer from the dopants to the semiconductors as well as controllable onset and threshold voltages, convertible charge‐transport polarity, and simultaneously showing excellent device stabilities under ambient air and bias stress conditions. This simple solution‐processed chemical doping approach could facilitate the understanding of both intrinsic and extrinsic charge transport characteristics in organic semiconductors and nanocarbon‐based materials, and is thus widely applicable for developing high‐performance organic and printed electronics and optoelectronics devices. 相似文献
18.
The self assembly of block‐copolymers into the gyroid morphology is replicated into 3D nanostructured conjugated polymers. Voided styrenic gyroidal networks are used as scaffolds for the electrodeposition of two poly(3,4‐ethylenedioxythiophene) derivatives and poly(pyrrole). The careful choice of solvents and electrolytes allows the excellent replication of the initial self‐assembled morphology into self‐supporting gyroidal conjugated polymer networks. The nanostructured films are employed to fabricate electrochromic devices, exhibiting excellent color contrast upon switching, with fast switching speeds. The versatility and reliability of this method are demonstrated by the creation of switchable Fresnel zone plates, with which the focussing of light can be switched on and off. 相似文献
19.
Mohammad Naraghi Graham H. Bratzel Tobin Filleter Zhi An Xiaoding Wei SonBinh T. Nguyen Markus J. Buehler Horacio D. Espinosa 《Advanced functional materials》2013,23(15):1883-1892
The production of carbon nanotube (CNT) yarns possessing high strength and toughness remains a major challenge due to the intrinsically weak interactions between “bare” CNTs. To this end, nanomechanical shear experiments between functionalized bundles of CNTs are combined with multiscale simulations to reveal the mechanistic and quantitative role of nanotube surface functionalization on CNT‐CNT interactions. Notably, the in situ chemical vapor deposition (CVD) functionalization of CNT bundles by poly(methyl methacrylate) (PMMA)‐like oligomers is found to enhance the shear strength of bundle junctions by about an order of magnitude compared with “bare” van der Waals interactions between pristine CNTs. Through multiscale simulations, the enhancement of the shear strength can be attributed to an interlocking mechanism of polymer chains in the bundles, dominated by van der Waals interactions, and stretching and alignment of chains during shearing. Unlike covalent bonds, such synergistic weak interactions can re‐form upon failure, resulting in strong, yet robust fibers. This work establishes the significance of engineered weak interactions with appropriate structural distribution to design CNT yarns with high strength and toughness, similar to the design paradigm found in many biological materials. 相似文献