Size Selective Incorporation of Gold Nanoparticles in Diblock Copolymer Vesicle Wall

Abstract

A systematic study is conducted to reveal how far the polymeric vesicle wall can embed gold nanoparticles (AuNPs) with different sizes by combining experiments and self-consistent field simulations. Both the experimental and simulative results indicate that the location of AuNPs in vesicle wall or in spherical micelle is heavily size dependent. Whether the AuNPs enter the vesicle wall or not is determined by a ratio of the diameter of AuNPs (D0) to the thickness of the vesicle wall (d(w0)). The 1-dodecanethiol-coated AuNPs (Au(x)R) with D0/d(w0) < 0.3 will stably disperse in the vesicle walls. For polystyrene-coated AuNPs (Au(x)S), a criterion of D0/d(w0) is proposed based on the phase diagram; i.e., the Au(x)S with D0/d(w0) < 0.5 can be located in the vesicle wall. Otherwise, the Au(x)R and the Au(x)S prefer to locate in spherical micelles. Moreover, the contributions of enthalpy and entropy to the total free energy of the system are respectively calculated to reveal the mechanism of the size selective distribution of AuNPs. The results demonstrate that the escape of AuNPs from vesicle walls and their selective distribution in spherical micelles is an entropy-driven process. Our study provides an important guideline for fabricating nanoparticle/block copolymer hybrid vesicles in dilute solution.

Toward Functional Synthetic Cells: In‐Depth Study of Nanoparticle and Enzyme Diffusion through a Cross‐Linked Polymersome Membrane

“…This observation leads to the conclusion that the size of the cargo is a limiting factor in the case of AuNPs for applying the postloading method. This insight corresponds to data analysis described in the literature and expands significantly the variety of known tailoring parameters of loading processes such as the composition and the membrane thickness of the vesicles.…”

“…The most distinct proof for cargo encapsulation is to directly visualize its location in the polymersome . For this reason gold nanoparticles (AuNPs) of either 5 or 10 nm in diameter were chosen as a cargo, because they offer an excellent contrast for cryo‐TEM measurements.…”

“…A direct analysis of cryo‐TEM images was performed to determine AuNPs locations based on approaches known from literature . However, one should take into account the technical restrictions of TEM that give 2D projections of 3D objects.…”

Phase manipulation of topologically engineered AB-type multi-block copolymers

“…[35][36][37] By coating gold NPs with either PS or PVP homopolymer and introducing them into poly(styrene-b-2 vinyl pyridine) (PS-PVP) diblock copolymers, Chiu et al 38 observed that those surface modied NPs can be localized within one or the other copolymer domain, as well as within the interface between the two blocks. Generally, the dispersion state of NPs depends strongly on the sizes, 39,40 packing fractions 41 and types [42][43][44] of NPs, which is attributed to the system entropy and also essential to control the microstructure of the copolymer mixtures. [42][43][44] Halevi et al 45 found that adding nanorods will have a bigger inuence on the copolymer phase transition behavior, shiing the systems morphology to exhibit both lamellae and cylinders, compared with nanoparticle at the same lling fraction.…”

New approach for producing fluorescent gold nanoparticles: Poly(ethylene oxide) homopolymers as reductants in the micelles of amphiphilic fluorosilicone-containing block copolymers

“…The synthesized AuNPs, meanwhile, need to be stabilized to achieve uniformity in particles size, usually with the use of stabilizing agents such as alkanethiols, poly(4‐vinylpyridine) (P4VP) and poly(ethylene oxide) (PEO)/poly(ethylene glycol) . In short, a typical approach to prepare AuNPs includes two steps, formation of AuNPs and stabilization to prevent particles from aggregation . Recently, more and more research works have been focusing on greener AuNPs preparation and stabilization …”