Jerczynski, Krzysztof; Muszynska, Julita; Demirci, Gokhan; Cetinkaya, Onur; Filipczak, Paulina; Nowaczyk, Grzegorz; Grobelny, Jaroslaw; Matyjaszewski, Krzysztof; Kozanecki, Marcin; Pietrasik, Joanna

This work reports on the efficient performance of hybrids particles with silver nanoparticles (AgNPs) distributed within single polymer molecules with star-like topology as Surface Enhanced Raman Scattering (SERS) supports. First, the library of the star-like polymers with poly (acrylic acid)-block-polystyrene (PAA-b-PS) arms was obtained via atom transfer radical polymerization (ATRP) using a “core-first” approach. Then, hybrid silver nanoparticles were synthesized in a controlled way within the prepared single molecules playing the role of molecular templates for AgNPs. Finally, the hybrid particles were tested as novel substrates for SERS using crystal violet as an analyte. Synthesized star-like templates had varied number of arms within the single star, the order of PAA and PS blocks, their degree of polymerization, and the molar ratio of the carboxylic groups of PAA block to the nanoparticles’ precursor. Additionally, the minimum analyte concentration required for SERS was determined. The number of arms within a polymer template plays a crucial role in the synthesis of silver nanoparticles and observed SERS effect. Prepared substrates were stable for long time and allowed the detection of the analytes on the nanomolar level.

AtıfScopus3·WoS3·OpenAlex3

İncele

Wypych-Puszkarz, Aleksandra; Cetinkaya, Onur; Yan, Jiajun; Udovytska, Ruslana; Jung, Jarosław; Jenczyk, Jacek; Nowaczyk, Grzegorz; Jurga, Stefan; Ulański, Jacek; Matyjaszewski, Krzysztof

Core−shell nanocomposites comprising barium titanate, BaTiO3 (BTO), and poly(methyl methacrylate) (PMMA) chains grafted from its surface with varied grafting densities were prepared. BTO nanocrystals are high-k inorganic materials, and the obtained nanocomposites exhibit enhanced dielectric permittivity, as compared to neat PMMA, and a relatively low level of loss tangent in a wide range of frequencies. The impact of the molecular dynamics, structure, and interactions of the BTO surface on the polymer chains was investigated. The nanocomposites were characterized by broadband dielectric and vibrational spectroscopies (IR and Raman), transmission electron microscopy, differential scanning calorimetry, and nuclear magnetic resonance. The presence of ceramic nanoparticles in core–shell composites slowed down the segmental dynamic of PMMA chains, increased glass transition temperature, and concurrently increased the thermal stability of the organic part. It was also evidenced that, in addition to segmental dynamics, local β relaxation was affected. The grafting density influenced the self-organization and interactions within the PMMA phase, affecting the organization on a smaller size scale of polymeric chains. This was explained by the interaction of the exposed surface of nanoparticles with polymer chains.

AtıfScopus10·WoS9·OpenAlex11

İncele