Homo- and Co-polymerization of Polysytrene-<i>block</i>-Poly(acrylic acid)-Coated Metal Nanoparticles

Wang, Hong; Song, Xiaohui; Liu, Cuicui; He, Jiating; Chong, Wen Han; Chen, Hongyu

doi:10.1021/nn502084a

Cited by 31 publications

(24 citation statements)

References 57 publications

(129 reference statements)

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“…In nanoscience and nanotechnology, capping agents are essential in stabilizing the ultrasmall surfaces of nanocrystals, allowing the synthesis and application of nanomaterials . More specifically, they control the surface charge and facets, and maintain the colloidal stability of nanoparticles …”

Section: Methodsmentioning

confidence: 99%

A New Type of Capping Agent in Nanoscience: Metal Cations

Liu

Wang

Cai

et al. 2019

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In nanoscience and nanotechnology, capping agents are essential in stabilizing the ultrasmall surfaces of nanocrystals, allowing the synthesis and application of nanomaterials. [1][2][3][4][5][6][7][8][9][10] More specifically, they control the surface charge and facets, and maintain the colloidal stability of nanoparticles. [11][12][13][14][15] Polyvinylpyrrolidone (PVP), a typical surfactant molecule, was initially used as a stabilizer in nanosynthesis, giving only spherical particles. [16,17] As its specific affinity to nanocrystal facets was discovered, PVP served not only as a stabilizing agent but also as a means to control the growth of nanocrystals, introducing a series of new morphologies, such as Ag nanocubes [18] and Ag nanowires. [19] Similarly, Ag nanoplates and Pd nanoplates were successfully synthesized by using citrate [20] and CO [21] as capping agents, respectively. Thus, the facet-controlling ability of capping agents is of great importance Capping agents are the essential factor in nanoscience and nanotechnology. However, the types of capping agents are greatly limited. Defying conventional beliefs, here is shown that metal cations can also be considered as capping agents for oxide nanoparticles, particularly in maintaining their colloidal stability and controlling their facets. Here the general stabilizing effects of multivalent cations for oxide nanoparticles, and the facet controlling role of Al 3+ ions in the growth and ripening of Cu 2 O octahedra, are demonstrated. This discovery broadens the view of capping agent and opens doors for nanosynthesis, surface treatment, and beyond.

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Section: Methodsmentioning

confidence: 99%

A New Type of Capping Agent in Nanoscience: Metal Cations

Liu

Wang

Cai

et al. 2019

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“…In this AuNP@BCP core–shell structure, hydrophobic PS or PMMA segment forms a compact interior layer to shield the AuNP core, while hydrophilic PAA serves as a corona layer to stabilize the core–shell NPs in aqueous solution. Moreover, it was found that both surface chemistry and the structural parameters (e.g., size) of AuNP significantly affected the morphologies of coassembly products . The concentric encapsulation of AuNP into polymer shell could only be realized when the AuNP capped with the hydrophobic ligand.…”

Section: Synthetic Approaches To Polymer‐conjugated Plasmonic Nanocrymentioning

confidence: 99%

Self‐Assembly of Polymer‐Coated Plasmonic Nanocrystals: From Synthetic Approaches to Practical Applications

Zhou

Chen

et al. 2018

Macromol. Rapid Commun.

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Such coupling can induce significant red-shifts in LSPR spectra and create greatly enhanced electromagnetic fields, both of which endow plasmonic assemblies with dramatically different optical properties compared to single PNC counterparts. [43,[48][49][50] Small molecular surfactants (i.e., hexadecyltrimethylammonium bromide-CTAB), [51] silica, [52][53][54] biomacromolecules (e.g., DNA), [55][56][57][58][59] and synthetic polymers are the most commonly used surface coatings for PNCs, [60,61] imparting surface functionalities to direct their selfassembly. Small molecular surfactants are able to provide decent stability in dielectric environments (e.g., aqueous solution), although their relatively small sizes makes it difficult to control interparticle spacing or intraparticle gap sizes. Both silica and DNA have been used as "spacers" for the SERS and fluorescence signal enhancement, but inherent size limits hold back their further extended uses. For example, the silica coating is difficult for building a gap of smaller than 10 nm, [52,62] while DNA has not demonstrated its utility in realizing a relatively large nanogap (i.e., >2 nm). [57,59] Consequently, such size-tuning limitation makes them challenging to offer sufficient structural flexibility to tailor the LSPR, which is crucial for obtaining an optimal enhancement effect (e.g., fluorescence enhancement). [52,63,64] Moreover, the coassembly of DNA and PNC is primarily based on the base-pairing recognition, [58,65,66] which is too specific for the extensive uses.In contrast, there are a number of benefits in conjugating polymers with PNCs to direct their self-assembly: i) The conformation transformation of polymer chains provides the driving force for self-assembly. [43,45,48,[67][68][69] For example, the amphiphilic single-component or mixed polymer brushes anchored onto the PNCs can afford amphiphilicity-driven self-assembly to produce a library of assemblies including core-shell structure, Janus nanoparticles (JNPs), nanocluster, nanochain, lamellae, and vesicle. ii) The polymeric corona protects the PNC core and stabilizes the assemblies in dispersion media. [68,70,71] iii) By using stimuli-responsive polymer coatings, the formed assemblies can readily undergo structural changes in response to the external triggers. [15,[72][73][74][75][76] Moreover, the strength of interactions between polymer/PNC hybrid materials and external stimuli can be adjusted by varying the structures of the polymer coating, such as molecular weight (M w ) of the polymer. The large-sized polymer coating leads to more significant multivalent effects compared to small molecular ligands. iv) Also important is Plasmonic Nanocrystals Self-assembly of plasmonic nanocrystals (PNCs) and polymers provides access to a variety of functionalized metallic-polymer building blocks and higher-order hybrid plasmonic assemblies, and thus is of considerable fundamental and practical interest. The hybrid assemblies often not only inherit individual characteristics of polymers and PNCs but also exhi...

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“…Many studies use various polymers [4] to understand this phenomenon, by exploring its porosity [5]. More recently nanostructures have been fabricated to help us explore ionic diffusion [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…Firstly, the hydrophobic polystyrene (PS) block of the polymer is able to self-assemble around the thiol-functionalized AuNP, protecting the core. Secondly, the poly(acrylic acid) (PAA) block helps maintain charge-charge repulsion, and hence allows the AuNP@PSPAA to maintain its stability in water [6]. While pores or voids may be found in the PS domain when placed in water [8], AuNP@PSPAAwere found to resist cyanide etching for months [9].…”

Section: Introductionmentioning

confidence: 99%