<i>In situ</i>synthesis of Ag nanoparticles in polyelectrolyte multilayers

Logar, Manca; Jančar, Boštjan; Suvorov, Danilo; Kostanjšek, Rok

doi:10.1088/0957-4484/18/32/325601

Cited by 45 publications

(49 citation statements)

References 30 publications

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“…The signal from the gold core was only observed in one of a total of 1000 particles, again due to the low absorption of gold in the IR (Manca et al, 2007;Pereira et al, 2015). The spectra of gold-PAH particles from the 266 nm fs LAAPTOF (not shown) also did not exhibit signal from the gold core, and only low signal intensity from the PAH shell.…”

Section: Sio 2 Particlesmentioning

confidence: 94%

Exploring femtosecond laser ablation in single-particle aerosol mass spectrometry

et al. 2018

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Abstract. Size, composition, and mixing state of individual aerosol particles can be analysed in real time using singleparticle mass spectrometry (SPMS). In SPMS, laser ablation is the most widely used method for desorption and ionization of particle components, often realizing both in one single step. Excimer lasers are well suited for this task due to their relatively high power density (10 7 -10 10 W cm −2 ) in nanosecond (ns) pulses at ultraviolet (UV) wavelengths and short triggering times. However, varying particle optical properties and matrix effects make a quantitative interpretation of this analytical approach challenging. In atmospheric SPMS applications, this influences both the mass fraction of an individual particle that is ablated, as well as the resulting mass spectral fragmentation pattern of the ablated material. The present study explores the use of shorter (femtosecond, fs) laser pulses for atmospheric SPMS. Its objective is to assess whether the higher laser power density of the fs laser leads to a more complete ionization of the entire particle and higher ion signal and thus improvement in the quantitative abilities of SPMS. We systematically investigate the influence of power density and pulse duration on airborne particle (polystyrene latex, SiO 2 , NH 4 NO 3 , NaCl, and custom-made core-shell particles) ablation and reproducibility of mass spectral signatures. We used a laser ablation aerosol time-of-flight single-particle mass spectrometer (LAAPTOF, AeroMegt GmbH), originally equipped with an excimer laser (wavelength 193 nm, pulse width 8 ns, pulse energy 4 mJ), and coupled it to an fs laser (Spectra Physics Solstice-100F ultrafast laser) with similar pulse energy but longer wavelengths (266 nm with 100 fs and 0.2 mJ, 800 nm with 100 fs and 3.2 mJ). We successfully coupled the freefiring fs laser with the single-particle mass spectrometer employing the fs laser light scattered by the particle to trigger mass spectra acquisition. Generally, mass spectra exhibit an increase in ion intensities (factor 1 to 5) with increasing laser power density (∼ 10 9 to ∼ 10 13 W cm −2 ) from ns to fs laser. At the same time, fs-laser ablation produces spectra with larger ion fragments and ion clusters as well as clusters with oxygen, which does not render spectra interpretation more simple compared to ns-laser ablation. The idea that the higher power density of the fs laser leads to a more complete particle ablation and ionization could not be substantiated in this study. Quantification of ablated material remains difficult due to incomplete ionization of the particle. Furthermore, the fslaser application still suffers from limitations in triggering it in a useful time frame. Further studies are needed to test potential advantages of fs-over ns-laser ablation in SPMS.

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Section: Sio 2 Particlesmentioning

confidence: 94%

Exploring femtosecond laser ablation in single-particle aerosol mass spectrometry

et al. 2018

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“…Finally, silver ions are reduced in situ using hydrogen or other reducing agents. In other works [31], it is possible to see other modifications of the LbL standard coating protocol in which silver nanoparticles are synthesized using the functional groups of weak polyelectrolytes and an additional reducing agent such as NaBH 4 .…”

Section: Introductionmentioning

confidence: 99%

Single-stage in situ synthesis of silver nanoparticles in antibacterial self-assembled overlays

et al. 2012

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In this work, a novel single-stage process for in situ synthesis of Ag nanoparticles (NPs) using the layer-bylayer (LbL) technique is presented. The Ag NPs were formed into nanotextured coatings based on sequentially adsorbed poly(allylamine hydrochloride) (PAH) and SiO 2 NPs. Such highly porous surfaces have been used in the fabrication of highly efficient ion release films for applications such as antibacterial coatings. In this approach, the amino groups of the PAH acted as reducing agent and made possible the in situ formation of the Ag NPs. This reduction reaction occurred during the LbL process as the coating was assembled, without any further step after the fabrication and stabilization of the multilayer film. Biamminesilver nitrate was used as the Ag + ion source during the LbL process and it was successfully reduced to Ag NPs. All coatings were tested with gram-positive and gram-negative bacterial cultures of Escherichia coli, Staphylococcus aureus, and Lactobacillus delbrueckii showing an excellent antimicrobial behavior against these types of bacteria (more than 99.9% of killing efficiency in all cases).

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“…In this respect, polymeric materials such as layer-by-layer assemblies [17,18] or microgels [19] have been widely used for the controlled synthesis of metallic nanostructures. In these cases, the size-related characteristics of the nanoclusters could be adjusted by either varying the experimental conditions during the reduction processes [20] or by priorly tuning the properties of the polymeric supports. [21] The present study represents a first successful attempt at controlling the formation of metallic nanoparticles by modifying the inner structure of a flat brush film.…”

Section: Introductionmentioning

confidence: 99%

Surface‐Grafted Gel‐Brush/Metal Nanoparticle Hybrids

Benetti

Sui

Zapotoczny³

et al. 2010

Adv Funct Materials

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Polymer brushes are classically defined and are to date employed as assemblies of macromolecules tethered at one end to a surface. The concept of preparing surface‐grafted gels by crosslinking such brushes is attractive since it gives rise to new opportunities related to the constraints present in this type of structure. Aiming at the development of nanostructured films possessing precisely adjustable chemical, mechanical, and optical properties, the present article describes the preparation of novel grafted layers based on gel‐brush/metal nanoparticle hybrids. These films were synthesized by surface‐initiated atom transfer radical polymerization of hydroxyethyl methacrylate with a small percentage of a crosslinker. The swelling, morphological, and mechanical properties of the gel‐brushes are shown to be highly dependent on the relative amount of crosslinker used. The gel‐brushes are subsequently used as matrixes for the controlled synthesis of silver nanoparticles with overall characteristics that are specifically tunable as a function of the macromolecular structure of the brush template.

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In situsynthesis of Ag nanoparticles in polyelectrolyte multilayers

Cited by 45 publications

References 30 publications

Exploring femtosecond laser ablation in single-particle aerosol mass spectrometry

Exploring femtosecond laser ablation in single-particle aerosol mass spectrometry

Single-stage in situ synthesis of silver nanoparticles in antibacterial self-assembled overlays

Surface‐Grafted Gel‐Brush/Metal Nanoparticle Hybrids

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