2 research outputs found
Controlling the Degree of Polymerization, Bond Lengths, and Bond Angles of Plasmonic Polymers
Plasmonic polymers present an interesting concept that
builds on
the analogy between molecular polymers and linear chains of strongly
interacting metal nanoparticles. Ensemble-averaged optical properties
of plasmonic polymers are strongly influenced by their structure.
In the present work, we formed plasmonic polymers by using solution-based
assembly of gold nanorods (NRs) end-tethered with photoactive macromolecular
tethers. By using postassembly ligand photo-cross-linking, we established
a method to arrest NR polymer growth after a particular self-assembly
time, and in this manner, using kinetics of step-growth polymerization,
we achieved control over the average degree of polymerization of plasmonic
polymers. Photo-cross-linking of ligands also enabled control over
the internanorod distance and resulted in the increased rigidity of
NR chains. These results, along with a higher structural integrity
of NR chains, can be utilized in plasmonic nanostructure engineering
and facilitate advanced applications of plasmonic polymers in sensing
and optoelectronics
Coassembly of Gold Nanoparticles and Cellulose Nanocrystals in Composite Films
Coassembly of nanoparticles with
different size-, shape-, and composition-dependent
properties is a promising approach to the design and fabrication of
functional materials and devices. This paper reports the results of
a detailed investigation of the formation and properties of free-stranding
composite films formed by the coassembly of cellulose nanocrystals
and shape-isotropic plasmonic gold nanoparticles. The effect of gold
nanoparticle size, surface charge, and concentration on the structural
and optical properties of the composite films has been studied. The
composite films retained photonic crystal and chiroptical activity
properties. The size and surface charge of gold nanoparticles had
a minor effect on the structure and properties of the composite films,
while the concentration of gold nanoparticles in the composite material
played a more significant role and can be used to fine-tune the optical
properties of materials derived from cellulose nanocrystals. These
findings significantly broaden the range of nanoparticles that can
be used for producing nanocomposite materials based on cellulose nanocrystals.
The simplicity of film preparation, the abundance of cellulose nanocrystals,
and the robust, free-standing nature of the composite films offer
highly advantageous features and pave the way for the generation of
functional materials with coupled optical properties