One-pot "green" synthesis of silver nanocomposites: A carboxy-terminated hyperbranched polyester polyol as an all-in-one reducing, self-organizing, and stabilizing nanoreactor

A one-pot «green» synthesis of silver nanocomposites (AgNPs) is proposed using carboxy-terminated hyperbranched polyester polyol (G2-estMA) as a reducing, stabilizing, and templating nanoreactor. Two initiation routes at molar ratio ν(AgNO3):ν(estMA)=1:70–1:4 were investigated: thermal (90–100 °C) and photoinitiation (UV 365 nm, 40 min). Products were characterized by UV-Vis, NTA, and TEM. Thermochemical synthesis yielded exclusively spheroidal AgNPs with efficiency governed by the competition between polymer reduction and stabilization. Optimal kinetics occurred at 1:50 (100 °C, 100 min), while 90 °C preserved spheroids only for 1:12–1:30. Photoinitiation enabled morphology control at room temperature. TEM resolved spectral ambiguities: SPR broadening for and was due to light scattering from polydisperse spheroids, not true anisotropy. Anisotropic silver rod-like structures formed exclusively at , where facet-selective stabilization matched the Ag⁺ supply. At , a sharp drop in hydrodynamic diameter alongside increased particle concentration indicated «burst nucleation», returning morphology to small spheroids. This approach offers a versatile platform to switch between monodisperse spheroids and anisotropic nanoparticles. Such biocompatible nanocomposites based on biodegradable G2-estMA and silver nanoparticles with controlled morphology are promising materials for targeted drug delivery, theranostics, and as active SERS substrates for protein detection in future.