The interplaying role of particle size and polymer layer thickness on the tunable optical response of polymer-coated Ag nanoparticles (NPs) has been studied experimentally and theoretically. A large redshift (\(\sim\) 38 nm) of surface plasmon resonance (SPR) peak position has been observed experimentally for Ag NPs of sizes in the range of 8−18 nm synthesized by polyol process with the varying concentration of metal precursor (AgNO\(_{3}\)) and using a surfactant (PVP) as a stabilizer. The observed large redshift of the SPR peak position of Ag NPs coated with PVP has been argued due to mainly change of NP size as well as change of local dielectric environment in the vicinity of the Ag NPs. The experimentally observed SPR peak shift has been explained by considering the system as a metal-core polymer-shell nanostructure. The change of local dielectric environment of the surrounding of the NPs is due to the change in the PVP layer on the NPs. Such observation has been confirmed through the theoretical studies considering the changes of NP size as well as the effective thickness of the PVP layers on the NPs. The SPR peak of the system with core-shell nanostructure has been found to vary linearly with the increase in radius of core and thickness of shell together. However, it changes exponentially with particle size alone. It has been found from a detailed study that the change in the ratio of radius of core and thickness of the shell is responsible for the observed redshift. Thus, the redshift of SPR peak position of Ag NPs cannot be justified by only considering the increase in particle size. Rather shell thickness has been found to play a prominent role in the SPR peak shift. This study can be used to understand the optical response of noble metal NPs coated with organic polymers.

已经通过实验和理论研究了粒径和聚合物层厚度对聚合物包覆的银纳米颗粒（NPs）的可调光学响应的​​相互作用。通过多元醇工艺合成的Ag NPs的大小随金属前驱物浓度的变化而在实验中观察到较大的红移（\（\ sim \） 38 nm）表面等离振子共振（SPR）峰位置（AgNO \（_ {3} \）），并使用表面活性剂（PVP）作为稳定剂。有人指出，观察到用PVP包覆的Ag NPs的SPR峰位置发生了较大的红移，这主要是由于NP尺寸的变化以及Ag NPs附近局部介电环境的变化。通过将系统视为金属核聚合物-壳纳米结构，可以解释实验观察到的SPR峰位移。NP周围的局部电介质环境的变化归因于NP上PVP层的变化。考虑到NP尺寸的变化以及NP上PVP层的有效厚度的理论研究已证实了这种观察。已经发现具有核-壳纳米结构的系统的SPR峰随核半径和壳厚度的增加而线性变化。然而，它仅随颗粒大小呈指数变化。通过详细的研究发现，芯半径与壳厚度之比的变化是观察到的红移的原因。因此，仅考虑粒径的增加不能证明Ag NPs的SPR峰位置的红移是合理的。已经发现壳厚度在SPR峰位移中起着重要作用。这项研究可用于了解涂覆有机聚合物的贵金属NP的光学响应。已经发现壳厚度在SPR峰位移中起着重要作用。这项研究可用于了解涂覆有机聚合物的贵金属NP的光学响应。已经发现壳厚度在SPR峰位移中起着重要作用。这项研究可用于了解涂覆有机聚合物的贵金属NP的光学响应。