Surface-enhanced Raman scattering (SERS) is a promising platform for particle-based sensor signaling, and droplet-based microfluidic systems are particularly advantageous for control of the size and composition of micro- and nanoparticles. For controlled sensing application, a high homogeneity of the sensor particles is a key requirement, and the particles with functional properties demand for the preparation in a minimum number of synthesis steps. Frequently used coflow and flow focusing arrangements, however, produce the microparticles of only larger size. To address such concern for downscaling of particle size, which is crucial for strong sensing outcome, we have used a peculiar micro cross-flow arrangement here for generating the polymer microparticles of broad size range between 30 and 600 μm along with in situ embedded silver nanoparticles. Embedded silver acts as nuclei for additional silver enforcement via silver-catalyzed silver deposition in order to realize the composite microparticles for SERS sensing. The homogeneous size and spatial distribution of silver nanoparticles inside the matrix and enforcement over the surface together with controlled pore size provides a high and homogeneous loading of polymer composite sensor. Moreover, different parameters such as analytes concentration and particles size have been studied here for SERS sensing application of biochemical molecules (amino acids and vitamins). Overall, the platform for size-tuned droplets generation, synthesis of composite microparticles, mechanism for synchronized photopolymerization-photoreduction, tuned silver enforcement, and the impacts of different analytes on differently composed microparticles are systematically investigated in this paper.

Potential biomedical applications such as controlled delivery with sustained drug release profile demand for multifunctional polymeric particles of precise chemical composition and with welldefined physicochemical properties. The real challenge is to obtain the reproducible and homogeneous nanoparticles in a minimum number of preparation steps. Here, single-step nanoarchitectures of soft surface layered copolymer nanoparticles with a regular tuning in the size via micro flow-through assisted synthesis are reported. Interfacial copolymerization induces the controlled compartmentalization where a hydrophobic core adopts spherical shape in order to minimize the surface energy and simultaneously shelter in the hydrophilic shelllike surface layer. Surface layer can swell in the aqueous medium and allow controlled entrapping of functional hydrophobic nanoparticles in the hydrophilic interior via electrostatic interaction which can be particularly interesting for combined fluorescence activity. Furthermore, the nanoarchitecture of size and concentration controlled polymer-metal nanoassembly particles can be implemented as an ideal surface-enhanced Raman scattering substrate for detection of the trace amounts of various analytes.

In this paper, a microfluidic approach has been used for the synthesis of ellipsoidal, dumbbell, rodlike, and necklacelike polymer nanoparticles. High yields of special types of nonspherical nanoparticles have been achieved by the implementation of an emulsion polymerization into microfluidic arrangement with a micro hole-plate reactor for the formation of monomer droplets. Here, in particular, the formation of nonspherical polymer nanoparticles is dependent on the presence of polyelectrolyte surface active molecules such as poly(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSS-co-PM), poly(sodium-p-styrenesulfonate) (PSSS), and polyanetholesulfonic acid sodium salt (PAES). The shapes and sizes of the interparticle nanoassemblies are precisely controlled by adjusting the concentration of polyelectrolytes in the aqueous phase, and by choosing suitable flow rate ratios (aqueous to monomer phase), respectively. The formation of polymer nanoparticles with different morphologies can be explained by a spontaneous in situ assembling under partial electrostatic repulsive control in the single step synthesis. The effect of particle charge and the competition between thermal motion of particles and electrostatic repulsion on the spontaneous assembling under the condition of a limited polarizability are discussed here as an important factor for the formation process of nonspherical polymer nanoparticles.

The rare earth‐rich intermetallic cadmium compounds RE10TCd3 (RE = Y, Tb – Tm, Lu; T = Fe, Co, Ni, Ru, Rh, Pd) were synthesized by induction melting of the elements in sealed niobium ampoules. These cadmium intermetallics crystallize with an ordered variant of the hexagonal Co2Al5 type, space group P63/mmc. The three crystallographically independent rare earth atoms lie on the aluminum sites, while the transition metal and cadmium atoms are ordered on the two cobalt positions. The structures of Y10Co1.103Cd2.897, Y10NiCd3, Y10RuCd3, Y10PdCd3, Er9.92FeCd3.08, and Er9.82NiCd3.18 were refined from single‐crystal X‐ray diffraction data. Some of the crystals showed small degrees of RE/Cd, respectively T/Cd mixing. The striking structural building units are transition metal centered T@RE6 trigonal prisms (TP) that are condensed to empty RE6 octahedra (O), building infinite …TP–O–O… rows in c direction. The second motifs are slightly flattened RE3@Cd6RE16 icosahedra. The latter are condensed via common triangular faced along the c axis. Each …TP–O–O… row is enrolled by three rows of condensed RE3@Cd6RE16 icosahedra in the motif of a hexagonal rod packing.

Controlled aggregation of polymer nanoparticles for building anisotropic nano- and microstructures via a self-assembling bottom-up process is an important strategy. Therefore, in this work, the formation of structured poly(methyl methacrylate) (PMMA) particles with diameters between lower micrometer and submicrometer range by use of a microcontinuous flow arrangement was investigated in the presence of nonionic water-soluble polymer polyvinylpyrrolidone (PVP). The investigations show that the microreaction strategy is well applicable and allows a tuning of size and shape of nanoparticles in dependence on reactant concentrations and flow rate ratios. Larger and complex structured polymer particles have been found at lower PVP concentration, whereas more compact submicron-sized particles were formed at higher PVP concentrations. The addition of ionic surfactants modulates the generation of characteristic particle shapes. The observation of intermediate states between complex flowerlike particles and simple spheres in dependence on the applied concentration of low molecular weight surfactants supports the explanation of particle formation by a mechanism with superposition of particle growth and assembling. When mixed surfactants (PVP-SDS or PVP-CTAB) are used, the final particles shape depends on the concentration of individual concentrations of surfactants and on the competition between mobility, solvation, and micelle formations.