Fabrication of SERS-active conjugated copolymers/gold nanoparticles composite films by interface-directed assembly

RSC Advances ◽  
2015 ◽  
Vol 5 (50) ◽  
pp. 39697-39704 ◽  
Author(s):  
Ya-Guang He ◽  
Sheng-Yu Shi ◽  
Na Liu ◽  
Yuan-Yuan Zhu ◽  
Yun-Sheng Ding ◽  
...  

A new composite film was synthesised by taking advantage of interface-directed assembly between thiol group-functionalized copolymers and Au NPs. The film not only exhibited strongly Au NP concentration-dependent SERS activity, but also allowed detection of a model molecule.

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Jui-Ming Yeh ◽  
Kuan-Yeh Huang ◽  
Su-Yin Lin ◽  
Yu-Yao Wu ◽  
Chao-Chen Huang ◽  
...  

A new and effective method has been developed where self-assembled gold nanoparticles (Au-NPs) of ∼10 nm diameter are successfully attached onto the surface of sidewalls and ends of thiol-terminated multi-walled carbon nanotubes (MWNTs) functionalized with orthomercaptoaniline, acting as a bridging agent. It can bridge the carbon nanotubes (CNTs) and Au-NPs via the bi-functional moiety with benzene unit at one end and thiol group at the other end by self-assembly. Theortho-mercaptoaniline was first grafted onto the surface of the CNTs viaπ-πinteraction between the benzene ring of the mercaptoaniline andπ-conjugated body of MWNTs surface to produce thiol-terminated CNTs. The bare surface of Au-NPs facilitates to attach on the thiol group of the thiol-terminated CNTs. Attenuated total reflectance FTIR, UV-visible, Raman spectroscopy and X-ray powder diffraction studies were used to verify whether the mercapto-benzene moieties have been attached to theπ-conjugated body of functionalized MWNTs. The direct evidence is obtained from transmission electron microscope (TEM) images where self-assembled Au-NPs are attached onto the functionalized MWNTs.


2012 ◽  
Vol 560-561 ◽  
pp. 756-760
Author(s):  
Qian Li ◽  
Fu Jie Chen

The research explores gold nanoparticles (NPs)/PVA/carbon black composite film and their further applications in humidity sensor chips, which include: 1. Novel humidity sensitive Au NPs/PVA/carbon black composite film has been prepared; 2. Humidity sensor chips based on Au NPs/PVA/carbon black composite film devices has been fabricated. The initial research works have been focused on the preparation of gold nanoparticles/PVA/carbon black composite film and the fabrication of humidity sensor chips. Performance of as-fabricated humidity sensor devices has been investigated and compared. In this work, the Au NPs are added to a highly plasticized polymer film doped with electrically conductive carbon black particles. As the film is exposed in the water vapor and its structural conformation changes, the Au NPs and carbon black particles would be redistributed, thereby changing the electrical resistance of the device. Humidity sensor chips have been fabricated using the Au NPs/polymer/carbon black composite film with the pixels defined through screen printer or chip writer. By converting the signals into a recorder, the changes of humidity can be tracked over the chip. The success of the research not only prepares novel humidity sensitive materials, but also provides promising applications in fabricating humidity sensor chips, which with low cost, reliable humidity detector other than those reported.


2012 ◽  
Vol 565 ◽  
pp. 615-620
Author(s):  
Bin Shen ◽  
Liang Wang ◽  
Su Lin Chen ◽  
Fang Hong Sun

The CVD diamond/diamond-like carbon composite film is fabricated on the WC-Co substrate by depositing a layer of Diamond-like Carbon film on the surface of conventional Micro- or Nano-crystalline diamond film. The hot filament chemical vapor deposition (HFCVD) method and vacuum arc discharge with a graphite cathode are adopted respectively to deposit the MCD/NCD and DLC films. A variety of characterization techniques, including filed emission scanning electron microscope (FE-SEM) and Raman spectroscopy are employed to investigate the surface morphology and atomic bonding state of as-deposited MCD/DLC and NCD/DLC composite film. The results show that both MCD/DLC and NCD/DLC composite films present similar surface morphology with the MCD and NCD films, except for scattering a considerable amount of small-sized diamond crystallites among the grain boundary area. The atomic-bonding state of as-deposited MCD/DLC and NCD/DLC composite films is determined by the top-layered DLC film, which is mainly consisted of amorphous carbon phase and no discernible sp3 characteristic peak can be observed from their Raman spectrum. Furthermore, the tribological properties of as-deposited MCD/DLC and NCD/DLC composite films is examined using a ball-on-plate reciprocating friction tester under both dry sliding and water-lubricating conditions, comparing with conventional DLC, MCD and NCD films. Silicon nitride balls are used as counterpart materials. For the CVD diamond/DLC composite films, the self-lubricating effect of top-layered DLC film is beneficial for suppressing the initial friction peak, as well as shortening the run-in period. The average friction coefficients of MCD/DLC and NCD/DLC composite films during stable sliding period are 0.07 and 0.10 respectively in dry sliding; while under water-lubricating condition, they further decreases to 0.03 and 0.07.


2021 ◽  
Author(s):  
Salvatore Moschetto ◽  
Andrea Ienco ◽  
Gabriele Manca ◽  
Manuel Serrano-Ruiz ◽  
Maurizio Peruzzini ◽  
...  

Heterostructures of single- and few-layer black phosphorus (2D bP) functionalized with gold nanoparticles (Au NPs) have been recently reported in the literature, exploiting their intriguing properties and biocompatibility for catalytic,...


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1908
Author(s):  
Hai Li ◽  
Sooman Lim

Self-polarized piezoelectric devices have attracted significant interest owing to their fabrication processes with low energy consumption. Herein, novel poling-free piezoelectric nanogenerators (PENGs) based on self-polarized polyvinylidene difluoride (PVDF) induced by the incorporation of different surface-modified barium titanate nanoparticles (BTO NPs) were prepared via a fully printing process. To reveal the effect of intermolecular interactions between PVDF and NP surface groups, BTO NPs were modified with hydrophilic polydopamine (PDA) and hydrophobic 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) to yield PDA-BTO and PFD-BTO, respectively. This study demonstrates that the stronger hydrogen bonding interactions existed in PFD-BTO/PVDF composite film comparative to the PDA-BTO/PVDF composite film induced the higher β-phase formation (90%), which was evidenced by the XRD, FTIR and DSC results, as well as led to a better dispersion of NPs and improved mechanical properties of composite films. Consequently, PFD-BTO/PVDF-based PENGs without electric poling exhibited a significantly improved output voltage of 5.9 V and power density of 102 μW cm−3, which was 1.8 and 2.9 times higher than that of PDA-BTO/PVDF-based PENGs, respectively. This study provides a promising approach for advancing the search for high-performance, self-polarized PENGs in next-generation electric and electronic industries.


Author(s):  
Spyridon Damilos ◽  
Ioannis Alissandratos ◽  
Luca Panariello ◽  
Anand N. P. Radhakrishnan ◽  
Enhong Cao ◽  
...  

AbstractA continuous manufacturing platform was developed for the synthesis of aqueous colloidal 10–20 nm gold nanoparticles (Au NPs) in a flow reactor using chloroauric acid, sodium citrate and citric acid at 95 oC and 2.3 bar(a) pressure. The use of a two-phase flow system – using heptane as the continuous phase – prevented fouling on the reactor walls, while improving the residence time distribution. Continuous syntheses for up to 2 h demonstrated its potential application for continuous manufacturing, while live quality control was established using online UV-Vis photospectrometry that monitored the particle size and process yield. The synthesis was stable and reproducible over time for gold precursor concentration above 0.23 mM (after mixing), resulting in average particle size between 12 and 15 nm. A hydrophobic membrane separator provided successful separation of the aqueous and organic phases and collection of colloidal Au NPs in flow. Process yield increased at higher inlet flow rates (from 70 % to almost 100 %), due to lower residence time of the colloidal solution in the separator resulting in less fouling in the PTFE membrane. This study addresses the challenges for the translation of the synthesis from batch to flow and provides tools for the development of a continuous manufacturing platform for gold nanoparticles.Graphical abstract


Nanoscale ◽  
2021 ◽  
Author(s):  
Lixiang Xing ◽  
Cui Wang ◽  
Yi Cao ◽  
Jihui Zhang ◽  
Haibing Xia

In this work, macroscopical monolayer films of ordered arrays of gold nanoparticles (MMF-OA-Au NPs) are successfully prepared at the interfaces of toluene-diethylene glycol (DEG) with a water volume fraction of...


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 285
Author(s):  
Lingfei Li ◽  
Qiu Sun ◽  
Xiangqun Chen ◽  
Zhaohua Jiang ◽  
Yongjun Xu

The low dielectric constant of the nonpolar polymer poly(1-butene) (PB-1) limits its application as a diaphragm element in energy storage capacitors. In this work, Ba(Zr0.2Ti0.8)O3-coated multiwalled carbon nanotubes (BZT@MWCNTs) were first prepared by using the sol–gel hydrothermal method and then modified with polydopamine (PDA) via noncovalent polymerization. Finally, PB-1 matrix composite films filled with PDA-modified BZT@MWCNTs nanoparticles were fabricated through a solution-casting method. Results indicated that the PDA-modified BZT@MWCNTs had good dispersion and binding force in the PB-1 matrix. These characteristics improved the dielectric and energy storage performances of the films. Specifically, the PDA-modified 10 vol% BZT@ 0.5 vol% MWCNTs/PB-1 composite film exhibited the best dielectric performance. At 1 kHz, the dielectric constant of this film was 25.43, which was 12.7 times that of pure PB-1 films. Moreover, its dielectric loss was 0.0077. Furthermore, under the weak electric field of 210 MV·m−1, the highest energy density of the PDA-modified 10 vol% BZT@ 0.5 vol% MWCNTs/PB-1 composite film was 4.57 J·cm−3, which was over 3.5 times that of PB-1 film (≈1.3 J·cm−3 at 388 MV·m−1).


2021 ◽  
pp. 095400832110003
Author(s):  
Ruiyi Li ◽  
Chengcheng Ding ◽  
Juan Yu ◽  
Xiaodong Wang ◽  
Pei Huang

In this article, the polyimide (PI) composite films with synergistically improving thermal conductivity were prepared by adding a few graphene nanoplatelets (GNP) and various hexagonal boron nitride (h-BN) contents into the PI matrix. The thermal conductivity of PI composite film with 1 wt% GNP and 30 wt% h-BN content was 1.21 W(m·k)− 1, which was higher than that of the PI composite film with 30 wt% h-BN content (0.45 W(m·k)− 1), the synergistic efficiency of GNP under various h-BN content (10 wt%, 20 wt%, and 30 wt%) were 1.70, 2.71, and 3.09, respectively. And it was found that the increased h-BN content can suppress the dielectric properties caused by GNP in the matrix. The dielectric permittivity and dielectric loss tangent of 1 wt% GNP/PI composite film were 10.69, 0.661 at 103 Hz, respectively, and that of the 30 wt% h-BN + GNP/PI composite film were 4.29 and 0.1367, respectively. Moreover, the mechanical properties of the PI composite film were suitable for practical applications. And the heat resistance index and the residual rate at 700°C of PI composite film increased to 326.8°C, 74.43%, respectively, and these of PI film were 292.6°C and 59.26%. Thus, it may provide a reference value for applying the filler hybridization/PI film in the electronic packaging materials.


Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 329
Author(s):  
Tan Yi ◽  
Minghui Qi ◽  
Qi Mo ◽  
Lijie Huang ◽  
Hanyu Zhao ◽  
...  

Composite films of polybutylene adipate terephthalate (PBAT) were prepared by adding thermoplastic starch (TPS) (TPS/PBAT) and nano-zinc oxide (nano-ZnO) (TPS/PBAT/nano-ZnO). The changes of surface morphology, thermal properties, crystal types and functional groups of starch during plasticization were analyzed by scanning electron microscopy, synchronous thermal analysis, X-ray diffraction, infrared spectrometry, mechanical property tests, and contact Angle and transmittance tests. The relationship between the addition of TPS and the tensile strength, transmittance, contact angle, water absorption, and water vapor barrier of the composite film, and the influence of nano-ZnO on the mechanical properties and contact angle of the 10% TPS/PBAT composite film. Experimental results show that, after plasticizing, the crystalline form of starch changed from A-type to V-type, the functional group changed and the lipophilicity increased; the increase of TPS content, the light transmittance and mechanical properties of the composite membrane decreased, while the water vapor transmittance and water absorption increased. The mechanical properties of the composite can be significantly improved by adding nano-ZnO at a lower concentration (optimum content is 1 wt%).


Sign in / Sign up

Export Citation Format

Share Document