Facile fabrication of flexible Si-based nanocomposite films as high-rate anodes by layer-by-layer self-assembly

2019 ◽  
Vol 476 ◽  
pp. 501-512 ◽  
Author(s):  
Lehao Liu ◽  
Meicheng Li ◽  
Lihua Chu ◽  
Bing Jiang ◽  
Ruoxu Lin
2020 ◽  
Vol 515 ◽  
pp. 146063 ◽  
Author(s):  
Yirong Xiao ◽  
Dongxue Guo ◽  
Tong Li ◽  
Qingfeng Zhou ◽  
Liguo Shen ◽  
...  

2010 ◽  
Vol 123-125 ◽  
pp. 189-192
Author(s):  
Hong Wei Shi ◽  
Li Zhang ◽  
Cong Wang ◽  
Ke Ying Zhang

Nanocomposite films containing Au nanoparticles were fabricated by alternating adsorption of poly(diallydimethyl ammonium chloride) (PDDA) and HAuCl4 using layer-by-layer self-assembly technique and subsequent in situ electrochemical reduction of the AuCl4- ions. The composition and properties of the composite films were characterized by ultraviolet-visible spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV).The UV-vis characteristic absorbances of PDDA and Au increase almost linearly with the number of bilayers, which suggests a progressive deposition with almost an equal amount of the PDDA and Au in each cycle. X-ray photoelectron spectroscopy further confirms the presence of the main components (such as PDDA and Au) of the nanocomposite films. Furthermore, the nanocomposite films also exhibit good electrocatalytic activity for the oxidation of ascorbic acid (AA), which may be used in electrochemical biosensors.


2012 ◽  
Vol 499 ◽  
pp. 63-66
Author(s):  
Ning Mei Hao ◽  
Dong Zhi Zhang ◽  
Bo Kai Xia ◽  
Kai Wang ◽  
Chun Yue Wan

Electrostatic layer-by-layer (LbL) self-assembly is widely used in sequential adsorption of nanometer-thick monolayers of oppositely charged polyelectrolytes to form a multi-layer film with molecular-level control over the architecture. To offer functional material for the potential application, this paper exploits PDDA and PSS as polycation and polyanion for LbL self-assembly to fabricate polyelectrolyte nanocomposite films. The preparation and film-growing mechanism is investigated under the influences of multi-factor such as polyelectrolyte concentration, ionic strength, and assembling duration using quartz crystal microbalance (QCM). The research results indicate the formation mechanism of multi-layer PDDA/PSS films and offer fundamental basis for the optimum preparation of polyelectrolyte films.


RSC Advances ◽  
2014 ◽  
Vol 4 (32) ◽  
pp. 16751-16758 ◽  
Author(s):  
Hao Liu ◽  
Xiaoyu Gu ◽  
Meng Hu ◽  
Yang Hu ◽  
Chaoyang Wang

Nanocomposite multilayer microcapsules are prepared by layer-by-layer self-assembly based on Pickering emulsions.


2000 ◽  
Vol 660 ◽  
Author(s):  
Dong Wook Kim ◽  
Alexandre Blumstein ◽  
Jayant Kumar ◽  
Changmo Sung ◽  
Sukant K. Tripathy

ABSTRACTMultilayer nanocomposite films have been prepared from exfoliated aluminosilicate/coumarin dye complex through layer-by-layer self-assembly using cationic polyelectrolytes. Coumarin dye molecules were intercalated into the layered aluminosilicate by an ion exchange reaction. Particles of the hectorite/dye complex were delaminated by extensive shaking and sonication of their water suspension into 2∼3 nm-thin silicate layers with molecules of the dye adsorbed on their surface. Atomic force microscopy and transmission electron microscopy data are in agreement with such a model. Ultrathin multilayered films were prepared using layer-by-layer self-assembly from the aluminosilicate platelets and a cationic polyelectrolyte polydiallyldimethylammonium chloride (PDAC). Linear build-up of the films up to 20 cycles was demonstrated and investigated using absorption spectroscopy and spectrofluorometer. The resulting transparent films have exhibited strong characteristic blue-green fluorescence due to coumarin dye molecules adhered to the exfoliated hectorite platelets.


2008 ◽  
Vol 23 (4) ◽  
pp. 1026-1035 ◽  
Author(s):  
Viatcheslav Vertlib ◽  
Marianne Dietiker ◽  
Michael Plötze ◽  
Lee Yezek ◽  
Ralph Spolenak ◽  
...  

This paper presents a spin-coating layer-by-layer assembly process to prepare multilayered polyelectrolyte-clay nanocomposites. This method allows for the fast production of films with controlled layered structure. The preparation of a 100-bilayer film with a thickness of about 330 nm needs less than 1 h, which is 20 times faster than conventional dip-coating processes maintaining the same hardness and modulus values. For validation of this technique, nanocomposite films with thicknesses up to 0.5 μm have been created with the common dip self-assembly and with the spin coating layer-by-layer assembly technique from a poly(diallyldimethylammonium)chloride (PDDA) solution and a suspension of a smectite clay mineral (Laponite). Geometrical characteristics (thickness, roughness, and texture) as well as mechanical characteristics (hardness and modulus) of the clay-polyelectrolyte films have been studied. The spin-coated nanocomposite films exhibit clearly improved mechanical properties (hardness 0.4 GPa, elastic modulus 7 GPa) compared to the “pure” polymer film, namely a sixfold increase in hardness and a 17-fold increase in Young’s modulus.


2007 ◽  
Vol 515 (20-21) ◽  
pp. 7870-7875 ◽  
Author(s):  
Xiaohong Liu ◽  
Jinqing Wang ◽  
Junyan Zhang ◽  
Bin Liu ◽  
Jinfang Zhou ◽  
...  

2002 ◽  
Vol 733 ◽  
Author(s):  
Liangmin Zhang ◽  
Fajian Zhang ◽  
R. O. Claus

AbstractUsing a novel electrostatic self-assembly (ESA) method to incorporate CdSe quantum dots into polymer we have successfully synthesized ultrathin films. This method allows the molecular-level thickness control and layer-by-layer formation of multilayer thin and thick films using alternative anionic and cationic molecular solution dipping. From ellipsometric measurements, we obtained that the thickness of per bilayer is around 3.7 nm. UV-vis absorption spectra versus the number of bilayers have also been obtained using an Hitachi 2001 spectrometer. The size of CdSe quantum dots has been measured using transmission electron microscopy before the CdSe quantum dots are incorporated and confirmed using atomic force microscopy after the formation of the film, respectively. Both measurements indicate that the diameter of the CdSe quantum dots is 2-3 nm. Xray photoelectron spectroscopy indicates that the concentration of the CdSe quantum dots in the film is 2.14%.


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