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1.
ACS Omega ; 4(1): 1816-1823, 2019 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-31459436

RESUMO

One-dimensional nanomaterials, including both nanowires (NWs) and nanotubes (NTs), have been extensively investigated in the decades because of their unique physicochemical properties. Particularly, aligning NWs/NTs into a network or complex micropatterns has been a key issue for its unique integrated functionalities, which enjoy benefits in versatile applications. So far, solution processes remain the most effective strategy to align NWs/NTs, which also bear advantages of mild operation condition and large-scale production. In this perspective, particular attention is drawn to the currently widely used solution coating approaches for aligning NWs/NTs, including the Langmuir-Blodgett film technique, solution shearing approaches, and methods of tri-phase contact line manipulation. We also proposed several perspectives in this field.

2.
Adv Mater ; 31(18): e1900534, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30882936

RESUMO

Nanowire (NW) based micropatterns have attracted research interests for their applications in electric microdevices. Particularly, aligning NWs represents an important process due to the as-generated integrated physicochemical advantages. Here, a facile and general strategy is developed to align NWs using fibrous elastocapillary coalescence of carbon nanotube arrays (ACNTs), which enables constructing multidimensional ordered NW micropatterns in one step without any external energy input. It is proposed that the liquid film of NW solution is capable of shrinking unidirectionally on the top of ACNTs, driven by the dewetting-induced elastocapillary coalescence of the ACNTs. Consequently, the randomly distributed NWs individually rotate and move into dense alignment. Meanwhile, the aggregating and bundling of ACNTs is helpful to produce carbon nanotube (CNT) yarns connecting neighboring bundles. Thus, a micropatterned NW network composed of a top-layer of horizontally aligned NWs and an under-layer of vertical ACNT bundles connected by CNT yarns is prepared, showing excellent performance in sensing external pressure with a sensitivity of 0.32 kPa-1 . Moreover, the aligned NWs can be transferred onto various substrates for constructing electronic circuits. The strategy is applicable for aligning various NWs of Ag, ZnO, Al2 O3 , and even living microbes. The result may offer new inspiration for fabricating NW-based functional micropatterns.

3.
ACS Appl Mater Interfaces ; 10(46): 39448-39454, 2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30394083

RESUMO

Solution processes have been widely used for making polymer films in organic photoelectric devices but suffer from difficulties in controlling the film formation. Here, by in situ characterization triphase contact lines (TCLs) in a brush-coating process, we clarify how TCLs affect the quality of as-prepared films. By fine-tuning the dewetting of a binary polymer solution (P3HT:PCBM) via different directions, TCLs with different patterns lead to films with different morphologies. High-quality nanothin films with larger crystallized sizes and higher orientations were enabled when TCLs were parallel to the brush edge, based on which the polymer solar cell shows higher power conversion efficiency (2.665%) compared with that of the spin-coated film.

4.
ACS Appl Mater Interfaces ; 10(32): 26819-26824, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30058324

RESUMO

Fibers exhibit excellent performance in liquid manipulation that is normally aroused by either the structural or the chemical gradient. Here, we developed radially arranged fiber arrays with different fibrous elasticities that exhibited distinctly different performances in liquid manipulation in terms of the fibrous elastocapillary coalescence, the high-efficiency water encapsulation, and the inability to manipulate liquid. It is proposed that the fiber elasticity acts as a driving force when interacting with liquid, equivalent with the structural and chemical gradient. We revealed the fundamental premise of how fiber elasticity affects its dynamic wetting behaviors, which sheds new light on the design of fiber systems with different liquid-manipulation abilities.

5.
J Am Chem Soc ; 140(28): 8690-8695, 2018 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-29894177

RESUMO

Fabrication of a high quality quantum dot (QD) film is essentially important for a high-performance QD light emitting diode display (QLED) device. It is normally a high-cost and multiple-step solution-transfer process where large amounts of QDs were needed but with only limited usefulness. Thus, developing a simple, efficient, and low-cost approach to fabricate high-quality micropatterned QD film is urgently needed. Here, we proposed that the Chinese brush enables the controllable transfer of a QD solution directly onto a homogeneous and ultrasmooth micropatterned film in one step. It is proposed that the dynamic balance of QDs was enabled during the entire solution transfer process under the cooperative effect of Marangoni flow aroused by the asymmetric solvent evaporation and the Laplace pressure different by conical fibers. By this approach, QD nanoparticles were homogeneously transferred onto the desired area on the substrate. The as-prepared QLED devices show rather high performances with the current efficiencies of 72.38, 26.03, and 4.26 cd/A and external quantum efficiencies of 17.40, 18.96, and 6.20% for the green, red, and blue QLED devices, respectively. We envision that the result offers a low-cost, facile, and practically applicable solution-processing approach that works even in air for fabricating high-performance QLED devices.

6.
Adv Mater ; 30(25): e1706938, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29707831

RESUMO

Recent years have witnessed the booming development of transparent flexible electrodes (TFEs) for their applications in electronics and optoelectronic devices. Various strategies have thus been developed for preparing TFEs with higher flexibility and conductivity. However, little work has focused on TFEs with anisotropic conductivity. Here, a facile strategy of directional liquid transfer is proposed, guided by a conical fibers array (CFA), based on which silver nanowires (AgNWs) are aligned on a soft poly(ethylene terephthalate) substrate in large scale. After further coating a second thin layer of the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), a TFE with notable anisotropic conductivity and excellent optical transmittance of 95.2% is prepared. It is proposed that the CFA enables fine control over the receding of the three-phase contact line during the dewetting process, where AgNWs are guided and aligned by the as-generated directional stress. Moreover, anisotropic electrochemical deposition is enabled where the Cu nanoparticles deposit only on the oriented AgNWs, leading to a surface with anisotropic wetting behavior. Importantly, the approach enables alignment of AgNWs via multiple directions at one step. It is envisioned that the as-developed approach will provide an optional approach for simple and low-cost preparation of TFE with various functions.

7.
ACS Nano ; 11(12): 12385-12391, 2017 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-29140678

RESUMO

Superhydrophobic carbon nanotube (CNT) films have demonstrated many fascinating performances in versatile applications, especially for those involving solid/liquid interfacial processes, because of their ability to affect the material/energy transfer at interfaces. Thus, developing superhydrophobic CNTs has attracted extensive research interests in the past decades, and it could be achieved either by surface coating of low-free energy materials or by constructing micro/nanohierarchical structures via various complicated processes. So far, developing a simple approach to fabricate stable superhydrophobic CNTs remains a challenge because the capillary force induced coalescence frequently happens when interacting with liquid. Herein, drawing inspirations from the lotus leaf, we proposed a simple one-step chemical vapor deposition approach with programmable controlled gas flow to directly fabricate a CNT film with rather stable superhydrophobicity, which can effectively prevent even small water droplets from permeating into the film. The robust superhydrophobicity was attributable to typical lotus-leaf-like micro/nanoscale hierarchical surface structures of the CNT film, where many microscale clusters composed of entangled nanotubes randomly protrude out of the under-layer aligned nanotubes. Consequently, dual-scale air pockets were trapped within each microscale CNT cluster and between, which could largely reduce the liquid/solid interface, leading to a Cassie state. Moreover, the superhydrophobicity of the CNT film showed excellent durability after long time exposure to air and even to corrosive liquids with a wide range of pH values. We envision that the approach developed is advantageous for versatile physicochemical interfacial processes, such as drag reduction, electrochemical catalysis, anti-icing, and biosensors.

8.
Adv Mater ; 29(45)2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29024229

RESUMO

Natural fibers have versatile strategies for interacting with water media and better adapting to the local environment, and these strategies offer inspiration for the development of artificial functional fibers with diverse applications. Wetting on fibers is a dynamic liquid-moving process on/in fibrous systems with various patterns, and the process is normally driven by the structural gradient, chemical gradient, elasticity of a single fiber, or the synergistic effect of these factors in multiple fibers in an integrated system in which the spatial geometry of the fibers is involved. Compared with the directional liquid movement on a single fiber, wetting on multiple fibers in both the micro- and macroscales is particularly fascinating, with various performances, including directional liquid transport, controllable liquid transfer, efficient liquid encapsulation, and capillary-induced fibrous coalescence. Based on these properties, fibrous materials offer an alternative open system for liquid manipulation that is applicable to various functional liquid materials. Here, recent achievements in bioinspired dynamic wetting on multiple fibers are highlighted, and perspectives on future directions are presented.

9.
Biomater Sci ; 3(9): 1270-8, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26236784

RESUMO

Multifunctional Fe3O4@polyacrylic acid/Au nanoclusters/zeolitic imidazolate framework-8 nanoparticles (Fe3O4@PAA/AuNCs/ZIF-8 NPs) integrating tri-modal cancer imaging (magnetic resonance, computed X-ray tomography and fluorescence imaging) and chemotherapy into a single system were fabricated by using a facile, mild and reproducible strategy. The obtained NPs possess many merits including ultrahigh doxorubicin (DOX) loading capability (1.54 mg DOX per mg NPs), dual pH-responsive controlled drug release, tri-modal cancer imaging ability, facile magnetic separation and good biocompatibility. Importantly, the NPs exhibit low systematic toxicity and high antitumor therapy efficacy in vivo through tail vein injection. Furthermore, the achievement of in vitro tri-modal cancer cell imaging reveals the potential of Fe3O4@PAA/AuNCs/ZIF-8 NPs for cancer diagnosis and visualized-synergistic therapy. Taken together, Fe3O4@PAA/AuNCs/ZIF-8 NPs can be developed as a promising theranostic agent that combines multiple capabilities for cancer treatment.


Assuntos
Antineoplásicos/farmacologia , Doxorrubicina/química , Compostos Férricos/química , Ouro/química , Células Hep G2/química , Nanopartículas/química , Compostos Organometálicos/química , Antineoplásicos/química , Linhagem Celular Tumoral , Meios de Contraste , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Células Hep G2/citologia , Humanos , Concentração de Íons de Hidrogênio , Nanopartículas/administração & dosagem , Compostos Organometálicos/metabolismo , Tomografia Computadorizada por Raios X
10.
J Mol Model ; 19(4): 1667-75, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23292251

RESUMO

By carrying out density functional theory (DFT) calculations, we have studied the effects of silicon (Si)-doping on the geometrical and electronic properties, as well as the chemical reactivity of carbon nanotubes (CNTs). It is found that the formation energies of these nanotubes increase with increasing tube diameters, indicating that the embedding of Si into narrower CNTs is more energetically favorable. For the given diameters, Si-doping in a (n, 0) CNT is slightly easier than that of in (n, n) CNT. Moreover, the doped CNTs with two Si atoms are easier to obtain than those with one Si atom. Due to the introduction of impurity states after Si-doping, the electronic properties of CNTs have been changed in different ways: upon Si-doping into zigzag CNTs, the band gap of nanotube is decreased, while the opening of band gap in armchair CNTs is found. To evaluate the chemical reactivity of Si-doped CNTs, the adsorption of NH3 and H2O on this kind of material is explored. The results show that N-H bond of NH3 and O-H bond of H2O can be easily split on the surface of doped CNTs. Of particular interest, the novel reactivity makes it feasible to use Si-doped CNT as a new type of splitter for NH3 and H2O bond, which is very important in chemical and biological processes. Future experimental studies are greatly desired to probe such interesting processes.

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