Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

• Zheren Du,
• Lianwei Chen,
• Tsung-Sheng Kao,
• Mengxue Wu and
• Minghui Hong

Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122

• efficiently attenuate high intensity light, needs to be improved. In this paper, we fabricate nanoparticles of different metals by laser ablation in liquid. We study the optical nonlinear properties of the laser-generated nanoparticle dispersion. Silica microspheres are used to enhance the optical limiting

• performance of the nanoparticle dispersion. The change in the optical nonlinear properties of the laser-generated nanoparticle dispersion caused by silica microspheres is studied. It is found that the incident laser beam is locally focused by the microspheres, leading to an increased optical nonlinearity of

• the nanoparticle dispersion. Keywords: laser ablation; local field enhancement; microspheres; nanoparticles; optical limiting; Introduction Laser ablation in liquid (LAL) is a versatile technique to fabricate nanoparticles. Conventional synthesis of nanoparticles by chemical reactions is usually

A simple approach to the synthesis of Cu_1.8S dendrites with thiamine hydrochloride as a sulfur source and structure-directing agent

• Xiaoliang Yan,
• Sha Li,
• Yun-xiang Pan,
• Zhi Yang and
• Xuguang Liu

Beilstein J. Nanotechnol. 2015, 6, 881–885, doi:10.3762/bjnano.6.90

• Bi2S3 without a template [11]. Li et al. demonstrated that L-cysteine could assist the formation of snowflake-like patterns and flower-like microspheres as well as porous hollow microsphere CuS structures [12]. Thiamine, abundant and inexpensive, contains one sulfur atom and is supposed to be used as a

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• poly(N-isopropylacrylamide)-coated luminescent/magnetic silica microspheres. The synthesis involved a sequence of three steps in which the first step led to the incorporation of iron oxide magnetic NPs inside silica spheres through the Stöber process. In the next step, negatively charged TGA

• profile of ibuprofen suggested that the drug release rate can be controlled by modifying the surface of the silica spheres. Further, Insin et al. [49] reported a sol–gel process for the synthesis of hybrid NPs embedded inside silica microspheres for fluorescence and magnetic resonance imaging. The

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• . [5] prepared chitosan/silica composite microspheres by mixing an aqueous solution of the biopolymer with commercial nanosized silica particles. The obtained microparticles were dried afterwards. In further examples, chitosan matrices have also been used to immobilize CdSe quantum dots [6] and γ-Fe2O3

• synthetic polymers (see Section 4 in [60] for a review), but only a limited number of works are found for biopolymers. Li et al. [61] prepared cross-linked chitosan microspheres and immobilized bovine serum albumin covalently on their surface. On the resulting particles, silica was formed by a sol–gel

• conventional sol–gel methods. The preparation of sol–gel silicates have been reported by several research groups [71][72]. Nevertheless, the use of chitosan is not limited to silicates and titanates. El Kadib et al. [73] demonstrated the use of chitosan microspheres as templates for vanadium, tungsten, and

Imaging the intracellular degradation of biodegradable polymer nanoparticles

• Anne-Kathrin Barthel,
• Martin Dass,
• Melanie Dröge,
• Jens-Michael Cramer,
• Daniela Baumann,
• Markus Urban,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2014, 5, 1905–1917, doi:10.3762/bjnano.5.201

• plates, millimetric beads, microspheres and cast films of PLLA [11]. By determination of the relative weight loss, they found that the bulkier samples degrade more rapidly (because the degradation rate is dominated by bulk disintegration processes) and surface hydrolysis seems to be considerably slower

Functionalized nanostructures for enhanced photocatalytic performance under solar light

• Liejin Guo,
• Dengwei Jing,
• Maochang Liu,
• Yubin Chen,
• Shaohua Shen,
• Jinwen Shi and
• Kai Zhang

Beilstein J. Nanotechnol. 2014, 5, 994–1004, doi:10.3762/bjnano.5.113

• . Ni2+-doped Cd1−xZnxS microspheres were prepared in our work. Here, the doped Ni2+ is expected to form a donor level above the valence band of Cd1−xZnxS and increase its visible light absorption. At the same time, its high conduction band can be still maintained. The enhanced photocatalytic activity

Antimicrobial nanospheres thin coatings prepared by advanced pulsed laser technique

• Alina Maria Holban,
• Valentina Grumezescu,
• Alexandru Mihai Grumezescu,
• Bogdan Ştefan Vasile,
• Roxana Truşcă,
• Rodica Cristescu,
• Gabriel Socol and
• Florin Iordache

Beilstein J. Nanotechnol. 2014, 5, 872–880, doi:10.3762/bjnano.5.99

• polymeric microspheres. Thus, Socol et al., [43], firstly reported the novel deposition of PLGA–PVA, PLGA–PVA–BSA (bovine serum albumin) and PLGA–PVA–CS microspheres by matrix assisted pulsed laser evaporation (MAPLE) technique. SEM images of thin coatings reveal homogeneous and spherical-shaped particles

• showed no concavities or distortions on their surface within an average diameter of 1 μm of the deposited spheres. It is noteworthy that the microspheres maintain their initial size and do not show an aggregative behavior [34]. All these type of microspheres have been prepared by an oil-in-water emulsion

• ) PLA–CS-Fe3O4@EUG microspheres in n-hexane. The radiation of a KrF* (λ = 248 nm, τFWHM = 25 ns) COMPexPro 205 Lambda Physics-Coherent excimer laser source model impinged the frozen targets at a laser fluence of 300–500 mJ/cm2 and a repetition rate of 15 Hz. In order to assure the reproducibility of the

One-step synthesis of high quality kesterite Cu₂ZnSnS₄ nanocrystals – a hydrothermal approach

• Vincent Tiing Tiong,
• John Bell and
• Hongxia Wang

Beilstein J. Nanotechnol. 2014, 5, 438–446, doi:10.3762/bjnano.5.51

• reaction duration are shown in Figure 6. Figure 6a illustrates that, prior to the hydrothermal process, the precipitate obtained from the precursor solution is consisting of microspheres with size around 20–250 nm. The HRTEM indicates that the microparticle is the result of aggregation of numerous oval

Preparation of NiS/ZnIn₂S₄ as a superior photocatalyst for hydrogen evolution under visible light irradiation

• Liang Wei,
• Yongjuan Chen,
• Jialin Zhao and
• Zhaohui Li

Beilstein J. Nanotechnol. 2013, 4, 949–955, doi:10.3762/bjnano.4.107

• diffraction peaks associated with NiS are observed in these samples, probably due to the low amount of NiS loaded and its high dispersion on ZnIn2S4. Figure 2a shows the TEM image of our previous studies that the hydrothermally prepared ZnIn2S4 sample was composed of microspheres with dimension in the range

• of 2–6 μm assembled by densely packed petals [16]. However, the TEM image of the current NiS/ZnIn2S4 sample shows that the ZnIn2S4 microspheres were partially decomposed after the second hydrothermal process (Figure 2b). Although no characteristic diffraction peaks corresponding to NiS nanoparticles

Low-temperature synthesis of carbon nanotubes on indium tin oxide electrodes for organic solar cells

• Andrea Capasso,
• Luigi Salamandra,
• Aldo Di Carlo,
• John M. Bell and
• Nunzio Motta

Beilstein J. Nanotechnol. 2012, 3, 524–532, doi:10.3762/bjnano.3.60

• 550 °C is expected to deteriorate the conductivity of the electrode even more strongly. This is partly supported by the formation of microspheres of indium on the ITO film, as observed by SEM and EDX (not shown). Similarly to what was reported by Lan et al. [27], we suggest that the exposure of the

• microspheres. In contrast, at 525 °C (Sample B) and 500 °C (Sample C), the degradation is not as severe and the conductivity of the film is still acceptable (25–30 Ω/sq). In these two cases the nanotubes nucleate with a lower density, and the substrates show a transmittance at 515 nm of 45 and 75

Colloidal lithography for fabricating patterned polymer-brush microstructures

• Tao Chen,
• Debby P. Chang,
• Rainer Jordan and
• Stefan Zauscher

Beilstein J. Nanotechnol. 2012, 3, 397–403, doi:10.3762/bjnano.3.46

• particles at a relatively low cost, (ii) that no complex equipment is required to create the patterned templates with micro- and nanoscale features, and (iii) that polymer brush features are controlled simply by changing the size or chemical functionality of the microspheres or the substrate. Keywords

• : atom-transfer radical polymerization; colloidal lithography; patterning; self-assembled microsphere monolayer; Introduction It is well known that monodisperse colloidal microspheres easily self-assemble into hexagonally close-packed arrays on surfaces as a result of capillary forces arising from the

• evaporation of solvents [1][2][3][4]. Such periodic arrays of microspheres were used already in the early 1980s by Fischer and co-workers as shadow masks in colloid lithography (CL) for the deposition of platinum nanomaterials [5]. Since then, CL has become a simple, versatile, and cost-effective fabrication

Switching adhesion forces by crossing the metal–insulator transition in Magnéli-type vanadium oxide crystals

• Bert Stegemann,
• Matthias Klemm,
• Siegfried Horn and
• Mathias Woydt

Beilstein J. Nanotechnol. 2011, 2, 59–65, doi:10.3762/bjnano.2.8

• size and material to the end of AFM cantilevers using an x-y-z-micromanipulator and an optical microscope. For the experiments presented here, titanium microspheres (Alfa Aesar GmbH) were conductively glued to the free end of tipless NSC12 cantilevers (Silicon-MDT Ltd.). The successful attachment of

• the spheres was verified by scanning electron microscopy (SEM), as shown in Figure 6. The titanium microspheres have a smooth surface and show normally an elastic response. In situ characterization of the spherical tips was performed by reverse tip imaging with the calibration grating TGT01 (Silicon