51
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Mechanically stable antimicrobial chitosan–PVA–silver nanocomposite coatings deposited on titanium implants. Carbohydr Polym 2015; 121:37-48. [DOI: 10.1016/j.carbpol.2014.12.027] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 01/12/2023]
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52
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Kumar P, Mathpal MC, Tripathi AK, Prakash J, Agarwal A, Ahmad MM, Swart HC. Plasmonic resonance of Ag nanoclusters diffused in soda-lime glasses. Phys Chem Chem Phys 2015; 17:8596-603. [DOI: 10.1039/c4cp05679e] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Silver nanoclusters were prepared in a soda-lime glass matrix through the ion-exchange method followed by thermal annealing. The work provides an insight into the nano-clustering and plasmonic effects of the nanoparticles.
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Affiliation(s)
- Promod Kumar
- Functional Nanomaterials Research Laboratory
- Department of Physics
- National Institute of Technology
- Srinagar-190006
- India
| | - Mohan Chandra Mathpal
- Department of Physics
- Motilal Nehru National Institute of Technology
- Allahabad-211004
- India
| | - Anand Kumar Tripathi
- Department of Physics
- Motilal Nehru National Institute of Technology
- Allahabad-211004
- India
| | - Jai Prakash
- Department of Physics
- University of the Free State
- Bloemfontein
- South Africa
| | - Arvind Agarwal
- Department of Physics
- Motilal Nehru National Institute of Technology
- Allahabad-211004
- India
| | - M. M. Ahmad
- Functional Nanomaterials Research Laboratory
- Department of Physics
- National Institute of Technology
- Srinagar-190006
- India
| | - H. C. Swart
- Department of Physics
- University of the Free State
- Bloemfontein
- South Africa
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53
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Polte J. Fundamental growth principles of colloidal metal nanoparticles – a new perspective. CrystEngComm 2015. [DOI: 10.1039/c5ce01014d] [Citation(s) in RCA: 416] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In the past few decades, much effort was put into the development of synthetic strategies to produce nanoparticles of different sizes and morphologies and a large number of scientific contributions are dedicated to the characterization and application of metal nanoparticles.
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Affiliation(s)
- Jörg Polte
- Humboldt-Universität zu Berlin
- Department of Chemistry
- 12489 Berlin, Germany
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54
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Hendel T, Wuithschick M, Kettemann F, Birnbaum A, Rademann K, Polte J. In situ determination of colloidal gold concentrations with UV-vis spectroscopy: limitations and perspectives. Anal Chem 2014; 86:11115-24. [PMID: 25289517 DOI: 10.1021/ac502053s] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This paper studies the UV-vis absorbance of colloidal gold nanoparticles at 400 nm and validates it as a method to determine Au(0) concentrations in colloidal gold solutions. The method is shown to be valid with restrictions depending on the investigated system. The uncertainty of the determined Au(0) concentration can be up to 30%. This deviation is the result of the combined influence of parameters such as particle size, surface modification, or oxidation state. However, quantifying the influence of these parameters enables a much more precise Au(0) determination for specific systems. As an example, the reduction process of the well-known Turkevich method was monitored and the Au(0) concentration was determined with a deviation of less than 5%. Hence, a simple, fast, easy, and cheap in situ method for Au(0) determination is demonstrated that has in the presence of other gold species such as Au(III) an unprecedented accuracy.
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Affiliation(s)
- Thomas Hendel
- Institut für Chemie, Humboldt-Universität zu Berlin , Brook-Taylor-Strasse 2, 12489 Berlin, Germany
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55
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Visaveliya N, Köhler JM. Control of shape and size of polymer nanoparticles aggregates in a single-step microcontinuous flow process: a case of flower and spherical shapes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12180-12189. [PMID: 25251615 DOI: 10.1021/la502896s] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Controlled aggregation of polymer nanoparticles for building anisotropic nano- and microstructures via a self-assembling bottom-up process is an important strategy. Therefore, in this work, the formation of structured poly(methyl methacrylate) (PMMA) particles with diameters between lower micrometer and submicrometer range by use of a microcontinuous flow arrangement was investigated in the presence of nonionic water-soluble polymer polyvinylpyrrolidone (PVP). The investigations show that the microreaction strategy is well applicable and allows a tuning of size and shape of nanoparticles in dependence on reactant concentrations and flow rate ratios. Larger and complex structured polymer particles have been found at lower PVP concentration, whereas more compact submicron-sized particles were formed at higher PVP concentrations. The addition of ionic surfactants modulates the generation of characteristic particle shapes. The observation of intermediate states between complex flowerlike particles and simple spheres in dependence on the applied concentration of low molecular weight surfactants supports the explanation of particle formation by a mechanism with superposition of particle growth and assembling. When mixed surfactants (PVP-SDS or PVP-CTAB) are used, the final particles shape depends on the concentration of individual concentrations of surfactants and on the competition between mobility, solvation, and micelle formations.
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Affiliation(s)
- Nikunjkumar Visaveliya
- Department of Physical Chemistry and Microreaction Technology, Technical University of Ilmenau , Weimarer Strasse 32, 98693 Ilmenau, Germany
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56
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Rivera VAG, Ledemi Y, El-Amraoui M, Messaddeq Y, Marega E. Control of the radiative properties via photon-plasmon interaction in Er3+ -Tm3+ -codoped tellurite glasses in the near infrared region. OPTICS EXPRESS 2014; 22:21122-21136. [PMID: 25321311 DOI: 10.1364/oe.22.021122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The novelty of this paper is that it reports on the tuning of the spectral properties of Er3+ -Tm3+ ions in tellurite glasses in the near-infrared region through the incorporation of silver or gold nanoparticles. These noble metal nanoparticles can improve the emission intensity and expand the bandwidth of the luminescence spectrum centered at 1535 nm, covering practically all the optical telecommunication bands (S, C + L and U), and extended up to 2010 nm wavelength under excitation by a 976 nm laser diode. Both effects are obtained by the combined emission of Er3+ and Tm3+ ions due to efficient energy transfer processes promoted by the presence of silver or gold nanoparticles for the (Er3+)4I(11/2)→(Tm3+)3H5, (Er3+)4I(13/2)→(Tm3+)3H4 and (Er3+)4I(13/2)→(Tm3+)3F4 transitions. The interactions between the electronic transitions of Er3+ and Tm3+ ions that provide a tunable emission are associated with the dynamic coupling mechanism described by the variations generated by the Hamiltonian H DC in either the oscillator strength or the local crystal field, i.e. the line shape changes in the near-infrared emission band. The Hamiltonian is expressed as eigenmodes associated with the density of the conduction electron generated by the different nanoparticles through its collective free oscillations at each resonance frequency of the nanoparticle and their geometric dependence. A complete description of photon-plasmon interactions of noble metal nanoparticles with the Er3+ and Tm3+ ions is provided.
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57
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Patra S, Pandey AK, Sen D, Ramagiri SV, Bellare JR, Mazumder S, Goswami A. Redox decomposition of silver citrate complex in nanoscale confinement: an unusual mechanism of formation and growth of silver nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2460-2469. [PMID: 24533743 DOI: 10.1021/la4048787] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We demonstrate for the first time the intrinsic role of nanoconfinement in facilitating the chemical reduction of metal ion precursors with a suitable reductant for the synthesis of metal nanoparticles, when the identical reaction does not occur in bulk solution. Taking the case of citrate reduction of silver ions under the unusual condition of [citrate]/[Ag(+)] ≫ 1, it has been observed that the silver citrate complex, stable in bulk solution, decomposes readily in confined nanodomains of charged and neutral matrices (ion-exchange film and porous polystyrene beads), leading to the formation of silver nanoparticles. The evolution of growth of silver nanoparticles in the ion-exchange films has been studied using a combination of (110m)Ag radiotracer, small-angle X-ray scattering (SAXS) experiments, and transmission electron microscopy (TEM). It has been observed that the nanoconfined redox decomposition of silver citrate complex is responsible for the formation of Ag seeds, which thereafter catalyze oxidation of citrate and act as electron sink for subsequent reduction of silver ions. Because of these parallel processes, the particle sizes are in the bimodal distribution at some stages of the reaction. A continuous seeding with parallel growth mechanism has been revealed. Based on the SAXS data and radiotracer kinetics, the growth mechanism has been elucidated as a combination of continuous autoreduction of silver ions on the nanoparticle surfaces and a sudden coalescence of nanoparticles at a critical number density. However, for a fixed period of reduction, the size, size distribution, and number density of thus-formed Ag nanoparticles have been found to be dependent on physical architecture and chemical composition of the matrix.
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Affiliation(s)
- Sabyasachi Patra
- Radiochemistry Division, Bhabha Atomic Research Centre , Trombay, Mumbai 400 085, India
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58
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Toda I, Tsuruoka T, Matsui J, Murashima T, Nawafune H, Akamatsu K. In situ synthesis of metal/polymer nanocomposite thin films on glass substrates by using highly cross-linked polymer matrices with tailorable ion exchange capabilities. RSC Adv 2014. [DOI: 10.1039/c3ra46166a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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59
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Yaseen MT, Chen M, Chang YC. Partially embedded gold nanoislands in a glass substrate for SERS applications. RSC Adv 2014. [DOI: 10.1039/c4ra08419e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We investigate the surface enhanced Raman scattering (SERS) of biomolecules attached to partially embedded gold nanoislands in a transparent substrate.
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Affiliation(s)
- Mohammad Tariq Yaseen
- Department of Engineering and System Science
- NTHU
- Hsinchu 300, Taiwan
- Nano Science and Technology Program
- Taiwan International Graduate Program
| | - Minfeng Chen
- Research Centre for Applied Sciences
- Academia Sinica
- Taipei, Taiwan
| | - Yia-Chung Chang
- Research Centre for Applied Sciences
- Academia Sinica
- Taipei, Taiwan
- Department of Physics
- National Cheng Kung University
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60
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Raghuwanshi VS, Ochmann M, Polzer F, Hoell A, Rademann K. Self-assembly of gold nanoparticles on deep eutectic solvent (DES) surfaces. Chem Commun (Camb) 2014; 50:8693-6. [DOI: 10.1039/c4cc02588a] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Self-assembly of gold nanoparticles in 1st and 2nd shell ordering is observed in a deep eutectic solvent (DES) by SAXS investigations.
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Affiliation(s)
| | - M. Ochmann
- Humboldt-Universität zu Berlin
- Institut für Chemie
- Berlin, Germany
| | - F. Polzer
- Humboldt-Universität zu Berlin
- Institut für Physik
- Berlin, Germany
- University of Delaware
- Department of Materials Science & Engineering
| | - A. Hoell
- Helmholtz Zentrum Berlin für Materialien und Energie
- Berlin, Germany
| | - K. Rademann
- Humboldt-Universität zu Berlin
- Institut für Chemie
- Berlin, Germany
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61
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Kuznetsov AS, Tikhomirov VK, Shestakov MV, Moshchalkov VV. Ag nanocluster functionalized glasses for efficient photonic conversion in light sources, solar cells and flexible screen monitors. NANOSCALE 2013; 5:10065-10075. [PMID: 23948871 DOI: 10.1039/c3nr02798h] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
An ever growing demand for efficient energy conversion, for instance in luminescent lamps, flexible screens and solar cells, results in the current significant growth of research on functionalized nanomaterials for these applications. This paper reviews recent developments of a new class of optically active nanostructured materials based on glasses doped with luminescent Ag nanoclusters consisting of only a few Ag atoms, suitable for mercury-free white light generation and solar down-shifting. This new approach, based solely on Ag nanocluster doped glasses, is compared to other alternatives in the field of Ag and rare-earth ion co-doped materials.
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Affiliation(s)
- A S Kuznetsov
- KU Leuven, INPAC - Institute for Nanoscale Physics & Chemistry, Celestijnenlaan 200D, 3001, Leuven, Belgium.
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62
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Water-soluble homo-oligonucleotide stabilized fluorescent silver nanoclusters as fluorescent probes for mercury ion. Mikrochim Acta 2013. [DOI: 10.1007/s00604-013-1045-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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63
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Hu R, Li G, Jiang Y, Zhang Y, Zou JJ, Wang L, Zhang X. Silver-zwitterion organic-inorganic nanocomposite with antimicrobial and antiadhesive capabilities. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:3773-9. [PMID: 23425314 DOI: 10.1021/la304708b] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In this work, we demonstrate a convenient, efficient, and environmentally benign strategy to achieving antimicrobial and antiadhesive purposes using a silver-zwitterion nanocomposite. The synthesis of the nanocomposite relies on loading zwitterionic polymer brushes with Ag(+) precursor ions, followed by their in situ reduction to Ag nanoparticle by ultraviolet (UV) irradiation. Both poly(sulfobetaine methacrylate) (pSBMA) and poly(carboxybetaine methacrylate) (pCBMA) have been studied as matrices for the embedding of silver. Well-dispersed silver nanoparticles are embedded into pCBMA matrices. The obtained pCBMA-silver hybrid (CB-Ag) is capable of killing bacteria upon contact and releasing dead bacteria under wet conditions. Results suggest the feasibility of using this nanocomposite system as a robust and reliable antimicrobial and antiadhesive platform for the prevention of microbial colonization.
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Affiliation(s)
- Rong Hu
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
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64
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Matsushita T, Fukumoto Y, Kawakami T, Tsuruoka T, Murashima T, Yanagishita T, Masuda H, Nawafune H, Akamatsu K. In situ template synthesis of one-dimensional gold nanoparticle arrays in organic nanowires. RSC Adv 2013. [DOI: 10.1039/c3ra42727g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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