Interfacial‐Active Polymer Nanoparticles, Their Assemblies, and SERS Application

Abstract

In this work, surface‐active polymer nanoparticles as well as polymer–polymer and polymer–metal nanoassembly particles are synthesized, and different parameters such as their size, morphologies, and assembling strength are studied. Nanoassembly particles are attractive because of the coupled properties with a large surface to volume ratio. A key challenge is to produce the core–shell polymer nanoparticles via single‐step processes. To address this concern, here, microfluidics approach and precise interfacial reaction strategies are used, and hence different types of surface layered polymer nanoparticles are obtained in one‐step processes. An inner core material is hydrophobic, whereas a hydrophilic surface layer (in situ formed during the polymerization process) swells in the aqueous environment. Moreover, three different reaction setups (batch, flow, and in situ) are applied in order to architect the nanoassembling hierarchical structures via layer‐by‐layer strategy. On the other side, polymer–metal nanoassembly particles as well as metal catalyzed metal deposited four layered nanoassembly particles of tuned size and compositions are produced. It is shown that these particles can be used as nanosensor particles for surface‐enhanced Raman spectroscopy.

Recent progress of microfluidics in surface‐enhanced Raman spectroscopic analysis

“…The miniaturization of reactor and the fluidic synthesis method provide enhanced mass transfer and heat exchange, flexible temporal-spatial control, as well as easy integration for automated post-treatment or application. For example, Visaveliya and coworkers [10] compared the affection of reaction setups on morphology of nanoassembly particles for SERS analysis. Batch reaction (Fig.…”

“…In AuNPs microfluidic synthesis, HAuCl 4 solution and trisodium citrate were injected into F I G U R E 2 Applications of microfluidics in SERS analysis F I G U R E 3 Comparison of reaction setups on morphology of SERS-active nanoassembly particles: three reaction setups of (A) batch reaction, (B) flow injection reaction, and (C) microfluidic reaction; the scanning electron microscope images of nanoassembly particles obtained via (D and E) two different batch reaction setup, (F) flow injection reaction setup, and (G) microfluidic reaction setup (reprinted from Ref. [10] with permission) microreactor through syringe pump, while a commercially available Peltier system was employed for temperature control. Their synthesized SERS-active AuNPs were sized in the range of 20-34 nm with satisfactory stability.…”

Metal Nano Networks by Potential‐Controlled In Situ Assembling of Gold/Silver Nanoparticles

“…This above drawn concept is in agreement with the phenomena observed in the case interaction of charged submicron polymer particles and the control of the interaction by the composition and ratios of surface‐attached polyionic macromolecules. In addition, branched structures could be achieved at certain concentrations and compositions of these aggregated polymer submicron particles …”

Friction and Mechanical Properties of Highly Filled Polybenzoxazine Composites: Nanosilica Particle Size and Surface Treatment

“…The variation of the coefficient of friction under different operating conditions is a very important issue. The coefficient of friction of nanocomposites can be affected by many factors such as mechanical behaviors, surface topography, particle size, particle surface treatment, and contents of filler …”

“…[38] The variation of the coefficient of friction under different operating conditions is a very important issue. The coefficient of friction of nanocomposites can be affected by many factors such as mechanical behaviors, surface topography, particle size, [39][40][41] particle surface treatment, [42,43] and contents of filler. [34] Therefore, effect of nanosilica contents, particle sizes, and surface treatments (polydimethylsiloxane (PDMS)-treated and dimethyldichlorosilane (DDS)-treated nanosilica particles) on mechanical, thermal, and physical properties of highly filled nanosilica-polybenzoxazine composites was examined in this research.…”