Electrical response from nanocomposite PDMS–Ag NPs generated byin situlaser ablation in solution

Abstract

Laser ablation technique is employed in order to generate polydimethylsiloxane (PDMS)/Ag NPs in situ, starting from a silver target in a solution of PDMS prepolymer and toluene. The produced surfactant-free nanoparticles are characterized by high resolution transmission electron microscopy (HRTEM) and scanning TEM-high angle annular dark field (STEM-HAADF) imaging modes, showing the majority of them to be of the order of 4 nm in diameter with a small percentage of larger Ag-AgCl multidomain NPs, embedded into a PDMS matrix. Low concentrations of carbon onion-like nanoparticles or larger fibers are also formed in the toluene-PDMS prepolymer solution. In accordance with this, UV-vis spectra shows no peak from silver NPs; their small size and their coverage by the PDMS matrix suppresses the signal of surface plasmon absorption. Inductively coupled plasma measurements reveal that the concentration of silver in the polymer is characteristically low, ~0.001% by weight. The electrical properties of the PDMS nanocomposite films are modified, with current versus voltage (I-V) measurements showing a low current of up to a few tenths of a pA at 5 V. The surface resistivity of the films is found to be up to ~10(10) Ω/sq. Under pressure (e.g. stress) applied by a dynamic mechanical analyzer (DMA), the I-V measurements demonstrate the current decreasing during the elastic deformation, and increasing during the plastic deformation.

Laser Synthesis and Processing of Colloids: Fundamentals and Applications

“…Because the shell is identical to the matrix and because no dispersants are needed, particle–polymer coupling can be directly achieved. Given that no matrix binders are needed between polymers (e.g., poly­(methyl methacrylate) [PMMA], polydimethylsiloxane [PDMS], PVP, , polyethylenimine [PEI], polyamidoamine [PAMAM], poly­( N -isopropylacrylamide) [PNIPAM], poly­(9-vinylcarbazole) [PVK], PVA, polystyrene [PS], and poly­(2-(diethylamino)­ethyl methacrylate) [PDEAEMA]) and inorganic NPs (e.g., metals, alloys, and semiconductors), in principle, unlimited types of polymer composites are obtainable . In addition, various biopolymers, such as starch, , gelatin, and chitosan, , or the biomacromolecule bovine serum albumin (BSA) , are increasingly interesting for use as biocompatible stabilizers to realize size-controlled and well-dispersed NPs, endowing NPs with much better stability than water .…”

“…polydimethylsiloxane [PDMS],709 PVP,206,429 polyethylenimine [PEI], 710 polyamidoamine [PAMAM], 595 poly(N-isopropylacrylamide) [PNI-PAM], 227 poly(9-vinylcarbazole) [PVK], 711 PVA, 712 polystyrene [PS], 713 and poly(2-(diethylamino)ethyl methacrylate) [PDEAEMA]…”

Fabrication and characterization of conductive poly(dimethylsiloxane)-carbon nanotube nanocomposites for potential microsensor applications

“…The specific point can be predicted by percolation theory (Niu et al, 2007) where maintaining elastic property, the composite shows acceptable level of conductivity. It has been shown that by changing the size of the conductive particles in the non-conducting matrix, from the micron to nano-sized dimensions and by increasing the aspect ratio of the conducting phase, the threshold of percolation for sensible conductivity is reduced (Kalyva et al, 2012). Because of the large aspect ratio of carbon nanotubes (100-10,000), many researchers have achieved low percolation thresholds for nanocomposites based on carbon nanotubes (Bryning et al, 2005).…”

Electric Field Assisted Femtosecond Laser Preparation of Au@TiO2 Composites with Controlled Morphology and Crystallinity for Photocatalytic Degradation

“…According to the nucleation and growth mechanism of nanocrystals, in addition to Ostwald’s ripening theory [ 32 ], Penn and Banfield also proposed some crystal growth modes such as directed attachment and directed aggregation [ 33 ]. In the crystallization pathway, large particles were grown from small primary particles by directed attachment, in which neighboring NPs self-assembled by sharing a common crystallographic orientation and combining these particles at a planar interface to lower the overall energy of the system [ 34 , 35 ]. Then, we attempted to vary the processing environment (applying an additional electric-field to change the additive light parameters) at the same laser fluence to investigate the effect of the electric field as well as the nature of the laser pulse on the Au crystal growth process.…”