3.1. Changes upon metal incorporation
The formation of CuNPs and AgNPs dispersed into polyol-modified matrices
was illustrated by marked color changes. The most visible changes took
place from blue to black and accounts for Cu2+conversion into Cu0 in the presence of
NaBH4 as a reduction agent. However, a less visible
color change was noticed for Ag+ conversion into
Ag0 in the solution (Fig. S4.a) . These
changes are much more pronounced in dry powders of H20@NaMt modified by
Cu0 and Ag0 and their cationic forms
(Fig. S4.b ). The same results were observed for similar metal
insertion in the presence of H20@CT-based samples. (Fig. S5).
Metal incorporation was confirmed by visible modification of the
morphology of surface of the host-material. Preliminary observation
through optical microscopy revealed a transition from a clean and almost
soft surface of NaMt to the appearance of grains on the surfaces of both
Cu0/ NaMt and Ag0/ NaMt
(Fig. S6 ). This provides evidence of the formation of metal
particles. Similar observations were made on CT-based materials
(Fig. S7 ). This was confirmed by additional analysis through of
SEM images of MNP-loaded NaMt and H20@CT (Fig. 1.a) . The
appearance of grains smaller than 100 nm indicates that metal salt
reduction using NaBH4 effectively produced spheroidal
nanoparticles with and without polyol as dispersing agent, as
illustrated by the behavior of NaMt alone and H20-coated CT material.
This can also be seen with CT alone (Fig. S8). The SEM images
of NaMt showed specific morphology changes of lamellar structure
according to the metal inserted (Fig. 1.a ). Larger crystalline
rods were observed on NaMt-Cu, presumably due to residual
Cu2+ salt.