Micro- and nano-surface structures based on vapor-deposited polymers

• Hsien-Yeh Chen

Beilstein J. Nanotechnol. 2017, 8, 1366–1374, doi:10.3762/bjnano.8.138

• with μCP or a photomask [49]. Gradient structures Surface gradients represent an advanced surface modification tool to exert gradient activities and/or communicate with the microenvironment using gradually altered cues. Such gradients include physical properties such as the wettability, thickness

Oxidative chemical vapor deposition of polyaniline thin films

• Yuriy Y. Smolin,
• Masoud Soroush and
• Kenneth K. S. Lau

Beilstein J. Nanotechnol. 2017, 8, 1266–1276, doi:10.3762/bjnano.8.128

• solvent-based methods becomes considerably more challenging due to the lack of solubility in common commercial solvents, which limits processability and leads to poor wettability. These challenges can be overcome with oxidative chemical vapor deposition (oCVD). oCVD is a single step, solvent-free

Preparation of thick silica coatings on carbon fibers with fine-structured silica nanotubes induced by a self-assembly process

• Benjamin Baumgärtner,
• Hendrik Möller,
• Thomas Neumann and
• Dirk Volkmer

Beilstein J. Nanotechnol. 2017, 8, 1145–1155, doi:10.3762/bjnano.8.116

• interactions between substrate and polyamine [28]. The nanograss films on glass were shown to have a potential application for surface wettability design [29][30][31]. In our study we focused on the coating of chopped carbon fibers and carbon fiber felts with silica by polyamine mediation. The polyamine is

Optical response of heterogeneous polymer layers containing silver nanostructures

• Miriam Carlberg,
• Florent Pourcin,
• Olivier Margeat,
• Judikaël Le Rouzo,
• Gérard Berginc,
• Rose-Marie Sauvage,
• Jörg Ackermann and
• Ludovic Escoubas

Beilstein J. Nanotechnol. 2017, 8, 1065–1072, doi:10.3762/bjnano.8.108

• optical index difference between the substrate and the thin film layer, thus a silicon wafer was chosen. The substrates were cleaned in an ultrasonic bath in acetone and ethanol, dried by nitrogen flow and an oxygen plasma. The latter step also increased the wettability of the substrate. The deposition of

Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting

• Sun-Kyu Lee,
• Sori Hwang,
• Yoon-Kee Kim and
• Yong-Jun Oh

Beilstein J. Nanotechnol. 2017, 8, 1049–1055, doi:10.3762/bjnano.8.106

• 184 PDMS. In the next imprinting step, an inorganically cross-linked sol–gel (ICSG) resist with a thickness (tf) of 400 nm was spin-coated on a Pyrex glass substrate. To improve the wettability of the resist, the glass surface was pretreated with a dielectric barrier discharge (DBD) using He and O2

Vapor-phase-synthesized fluoroacrylate polymer thin films: thermal stability and structural properties

• Paul Christian and
• Anna Maria Coclite

Beilstein J. Nanotechnol. 2017, 8, 933–942, doi:10.3762/bjnano.8.95

• -PFDA and cross-linked alterations thereof are chemically stable in the investigated temperature range, within the detection limits of the FTIR spectroscopy measurement. Surface morphology and wettability The impact of the cross-linker on the surface morphology of p-PFDA films was investigated by atomic

• , indicating good stability towards temperature variation in the investigated range. Changes in the surface morphology and chemistry also affect the wettability, as evidenced by a decreasing water contact angle (WCA) upon EGDMA addition to the polymer (Figure 4a). While the PFDA homopolymer forms a highly

• PFDA homopolymer. For the EGDMA homopolymer, a WCA of 69 ± 1° was ultimately observed. The change in wettability stems from the (relative) increase of carbonyl groups upon addition of EGDMA, which turns the polymer more hydrophilic. Similar to the morphological changes discussed above, heat treatment

Impact of surface wettability on S-layer recrystallization: a real-time characterization by QCM-D

• Jagoba Iturri,
• Ana C. Vianna,
• Alberto Moreno-Cencerrado,
• Dietmar Pum,
• Uwe B. Sleytr and
• José Luis Toca-Herrera

Beilstein J. Nanotechnol. 2017, 8, 91–98, doi:10.3762/bjnano.8.10

• isolated SbpA bacterial surface proteins onto silicon dioxide substrates of different surface wettability. Surface modification by UV/ozone oxidation or by vapor deposition of 1H,1H,2H,2H-perfluorododecyltrichlorosilane yielded hydrophilic or hydrophobic samples, respectively. Time evolution of frequency

• : bacterial S-layers; Quartz crystal microbalance with dissipation monitoring (QCM-D); recrystallization kinetics; surface wettability; Introduction Crystalline bacterial protein layers (S-layers) are arrays of (glyco)proteins (Mw of 40 to 200 kDa) forming the outermost envelope of prokaryotes, and represent

• yet to be solved about the S-layer recrystallization process under different physico-chemical conditions of the substrate (i.e., wettability or the presence of specific chemical groups and receptors), such as the different adsorption kinetics, crystal domain sizes and lattice symmetry parameters

Morphology of SiO₂ films as a key factor in alignment of liquid crystals with negative dielectric anisotropy

• Volodymyr Tkachenko,
• Antigone Marino,
• Eva Otón,
• Noureddine Bennis and
• Josè Manuel Otón

Beilstein J. Nanotechnol. 2016, 7, 1743–1748, doi:10.3762/bjnano.7.167

• well-formed columnar structure dominates LC orientation; however, βLC is somewhat larger than βSiO2 which can be caused by good wettability of the orienting surface by the LC [5]. Conclusion To summarize, we investigated the anisotropic optical properties of thin SiO2 layers as a function of the

Surface roughness rather than surface chemistry essentially affects insect adhesion

• Matt W. England,
• Tomoya Sato,
• Makoto Yagihashi,
• Atsushi Hozumi,
• Stanislav N. Gorb and
• Elena V. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1471–1479, doi:10.3762/bjnano.7.139

• of surface, each with different chemical and topographical properties. The results of traction force tests clearly demonstrated that chemical surface properties, such as static/dynamic de-wettability of water and oil caused by specific chemical compositions, had no significant effect on the

• surface could move, without pinning, more smoothly than they could on a smooth FAS17 surface (Δθ = 13°). The relationships between surface wettability and chemical composition of our sample surfaces were established using XPS. The surface chemical compositions of each sample are summarized in Table 2. All

• , rather than C and F concentrations, had the strongest influence upon surface wettability. Based on the surface chemical and physical properties of our samples shown above, we next examined the attachment ability of Coccinella septempunctata beetles by measuring their traction forces on these surfaces

Effect of tetramethylammonium hydroxide/isopropyl alcohol wet etching on geometry and surface roughness of silicon nanowires fabricated by AFM lithography

• Siti Noorhaniah Yusoh and
• Khatijah Aisha Yaacob

Beilstein J. Nanotechnol. 2016, 7, 1461–1470, doi:10.3762/bjnano.7.138

• generated bubbles coming off the near the SOI surface, influencing the surface roughness [7][29]. The density and size of hillocks is influenced by the hydrogen bubble formation during the etching process. The addition of IPA produces a smooth surface (Figure 9) because it promotes the wettability of the

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• graphite exfoliation if mixed with particular solvents such as water. Specifically, they can change the wettability and prevent aggregation due to electrostatic repulsion [95]. The main problem with the liquid-phase exfoliation method is that it produces graphene for films that is not completely

Nanostructured surfaces by supramolecular self-assembly of linear oligosilsesquioxanes with biocompatible side groups

• Maria Nowacka,
• Anna Kowalewska and
• Tomasz Makowski

Beilstein J. Nanotechnol. 2015, 6, 2377–2387, doi:10.3762/bjnano.6.244

• underlying matrix. For example, surfaces carrying COOH groups were applied for studies on the effect of surface wettability on protein adsorption and adhesion of human umbilical vein endothelial cells (HUVECs) and HeLa cells [3], human fibroblasts [14], human mesenchymal stem cells [15][22], corneal

• Owens–Wendt geometric mean Equation S1 described in Supporting Information File 1 [55]). We have previously reported [37][38] that the very good wettability of mica coated with LPSQ-COOH is a result of the structure of adsorbed nanolayers and the fact that carboxylic groups attached to oligomers of LPSQ

• -COOH adopt a specific conformation at the interface with air. We have analysed the wettability of samples covered with other LPSQ-COOH/X schemes (Figure 2) to find that, in spite of their different morphology, they exhibit almost the same surface energy and the ratio between polar and dispersive forces

Nanostructured superhydrophobic films synthesized by electrodeposition of fluorinated polyindoles

• Gabriela Ramos Chagas,
• Thierry Darmanin and
• Frédéric Guittard

Beilstein J. Nanotechnol. 2015, 6, 2078–2087, doi:10.3762/bjnano.6.212

• advantages such as an easiness to functionalize and opto-electronic properties [16] with the possibility to introduce various dopants (smart materials) [17][18]. Conducting polymers are also exceptional materials for the control of surface nanostructures and wettability. First of all, nanostructures of

• during the reaction and the polymerization is not favorable. Surface structures and wettability The surface structures were characterized by scanning electron microscopy (SEM) and surface roughness measurements. The SEM images for Qs = 100 mC·cm−2 are given in Figure 3 and Figure 4 and the surface

• first instance [26][34]. Hence, higher roughness of PIndole-6-Fn can be explained by the formation of longer polymer chains. PIndole-5-F4 and PIndole-6-F4 also showed an increase in roughness for normalized charges of 50 and 100 mC·cm−2 without significant changes in the wettability comparing the others

Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

• Xiaoxing Ke,
• Carla Bittencourt and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2015, 6, 1541–1557, doi:10.3762/bjnano.6.158

• triangular shaped nanoparticles on CNT walls with an increased area at the contact interface, and Ti forms an amorphous film with continuous coverage around the CNTs. These results are further associated with the wettability of different metals on the CNT surface and explained by electron affinity and

• reported that the deformation of Au-contacted CNT walls is more prominent compared to Pd-contacted CNT walls (not shwon), which could be associated to higher wettability of Pd over Au nanoparticles on one hand. On the other hand, a deformation mechanism through elastic strain relaxation is also proposed

Applications of three-dimensional carbon nanotube networks

• Manuela Scarselli,
• Paola Castrucci,
• Francesco De Nicola,
• Ilaria Cacciotti,
• Francesca Nanni,
• Emanuela Gatto,
• Mariano Venanzi and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 792–798, doi:10.3762/bjnano.6.82

• wettability is well described by a Cassie–Baxter model [20] for which a quite rough surface allows air trapping and ensures the high contact angle measured. In particular, in such a system pores in the random network (i.e., void fraction) favor air trapping due to the strong capillary force that the surface

Self-assembled anchor layers/polysaccharide coatings on titanium surfaces: a study of functionalization and stability

• Ognen Pop-Georgievski,
• Dana Kubies,
• Josef Zemek,
• Neda Neykova,
• Roman Demianchuk,
• Eliška Mázl Chánová,
• Miroslav Šlouf,
• Milan Houska and
• František Rypáček

Beilstein J. Nanotechnol. 2015, 6, 617–631, doi:10.3762/bjnano.6.63

• wettability of the surface, yielding enhanced osteoblast differentiation [19]. The success of these modifications is highly dependent on the chemical state, reactivity and surface concentration of the hydroxy groups, as well as the presence of contaminants [12]. Therefore, one of the main objectives of this

• angle measurement: The wettability of the organic surfaces on flat, titanium reference surfaces was examined by a static sessile water drop method using a DataPhysics OCA 20 contact angle system. Each sample was characterized using four 3 μL drops of material. The data were evaluated using the Young

• –Laplace method. The wettability of the commercially available, rough titanium substrates upon different treatments was estimated by measuring the advancing and receding water contact angles utilizing the dynamic Wilhelmy plate method. The measurements were performed on a Kruss K12 (Germany) tensiometer

Synergic combination of the sol–gel method with dip coating for plasmonic devices

• Cristiana Figus,
• Maddalena Patrini,
• Francesco Floris,
• Lucia Fornasari,
• Paola Pellacani,
• Gerardo Marchesini,
• Andrea Valsesia,
• Flavia Artizzu,
• Daniela Marongiu,
• Michele Saba,
• Franco Marabelli,
• Andrea Mura,
• Giovanni Bongiovanni and
• Francesco Quochi

Beilstein J. Nanotechnol. 2015, 6, 500–507, doi:10.3762/bjnano.6.52

• , which affects film wettability, and the sol dilution. This change in the contact angle is probably due to the modification of the silica microstructure induced by an increase of the ethanol concentration, which is also supported by the decrease of the refractive index values for films prepared from

• , the fresh films deposited on the glass substrate were cut with a scalpel. After 48 h at room temperature, this cut on the film was observed by AFM for the thickness estimation. The evaluation of the surface roughness and thickness was performed by using WSxM 5.0 Develop3.2 software. The wettability of

Conformal SiO₂ coating of sub-100 nm diameter channels of polycarbonate etched ion-track channels by atomic layer deposition

• Nicolas Sobel,
• Christian Hess,
• Manuela Lukas,
• Anne Spende,
• Bernd Stühn,
• M. E. Toimil-Molares and
• Christina Trautmann

Beilstein J. Nanotechnol. 2015, 6, 472–479, doi:10.3762/bjnano.6.48

• aspect ratio nanochannels with SiO2 films of a few nanometres thickness in a tailored manner. This information is of great relevance for ALD applications on high-aspect-ratio nanochannels in general as well as for the development of further chemical modifications on the SiO2 coating. Wettability The

• wettability of uncoated and SiO2-coated track-etched membranes was investigated by contact angle measurements. Figure 6 shows the contact angle as a function of the number of ALD cycles. The contact angle decreases with increasing thickness of the SiO2 layer, evidencing that the membrane surface changes its

• character from hydrophobic to hydrophilic. Above a layer thickness of about 7 nm, the surface shows excellent wettability. Conclusion Cylindrical nanochannels in polycarbonate track-etched membranes with diameter of about 50 nm were conformally coated with SiO2 layers of thickness 5, 10, 15, and 18 nm by

In situ scanning tunneling microscopy study of Ca-modified rutile TiO₂(110) in bulk water

• Giulia Serrano,
• Beatrice Bonanni,
• Tomasz Kosmala,
• Marco Di Giovannantonio,
• Ulrike Diebold,
• Klaus Wandelt and
• Claudio Goletti

Beilstein J. Nanotechnol. 2015, 6, 438–443, doi:10.3762/bjnano.6.44

• application of Ti-based biomaterials, since the augmented wettability would enhance the interaction between the implant surface and the biological environment. In this paper we present an in situ STM investigation of a Ca overlayer thermally grown in UHV on the TiO2(110) rutile surface and then immersed in

Exploiting the hierarchical morphology of single-walled and multi-walled carbon nanotube films for highly hydrophobic coatings

• Francesco De Nicola,
• Paola Castrucci,
• Manuela Scarselli,
• Francesca Nanni,
• Ilaria Cacciotti and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 353–360, doi:10.3762/bjnano.6.34

• wettability. It is indeed well-established [12][13] that on composite rough surfaces a hierarchical morphology may induce a wetting transition from Wenzel [1] to Cassie–Baxter [9] state owing to air trapping. Moreover, this transition may occur by passing through thermodynamically metastable states [13][14

• film [44] that enhances the wettability of the carbon nanotube surface, when the interaction with the liquid is lipophilic. Furthermore, we studied the stability of our carbon nanotube films over time by performing suction experiments. Figure 5 reports the variations of the contact angle value as a

Oxygen-plasma-modified biomimetic nanofibrous scaffolds for enhanced compatibility of cardiovascular implants

• Anna Maria Pappa,
• Varvara Karagkiozaki,
• Silke Krol,
• Spyros Kassavetis,
• Dimitris Konstantinou,
• Charalampos Pitsalidis,
• Lazaros Tzounis,
• Nikos Pliatsikas and
• Stergios Logothetidis

Beilstein J. Nanotechnol. 2015, 6, 254–262, doi:10.3762/bjnano.6.24

• highly porous structures. Thus, in our case, contact angle measurements are not a reliable technique to gain results concerning the wettability and the surface energy of each system independently [28]. In order to determine the chemical composition of the O2-plasma-treated samples as well as the chemical

Boosting the local anodic oxidation of silicon through carbon nanofiber atomic force microscopy probes

• Gemma Rius,
• Matteo Lorenzoni,
• Soichiro Matsui,
• Masaki Tanemura and
• Francesc Perez-Murano

Beilstein J. Nanotechnol. 2015, 6, 215–222, doi:10.3762/bjnano.6.20

• comparing CNF against Si tips. However, in the tested voltage range we could observe a strong widening of the features when the voltage exceeds 14 V. This is probably due to a different wettability of the CNF tips which results in a wider water neck when the voltage exceeds a certain critical value

• shows an increased oxide growth rate, compared to bare-Si probes which we attribute to the shape and chemistry of the CNF tip. Particularly, concentration of the electric field due to the high aspect ratio provided by the CNF apex and changes in wettability, affecting water meniscus shape, with respect

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• PTFE could serve as a suitable binder [12][24]. PTFE not only glues the catalyst particles together and, hence, keeps the catalyst layer mechanically intact with its hydrophobic nature; it also controls the wettability of the GDE, which affects the infiltration of phosphoric acid into the GDE. Both the

• “skin” on the electrode surface. This PTFE-rich layer affects not only the surface conductivity but also the wettability of the catalyst layer. The high PTFE content created a hydrophobic electrode surface, which slowed down the phosphoric acid uptake during the start-up period of the MEA. Mack et al

• wettability of the GDE and, in particular, the triple phase boundary between gas reactant, electrolyte and catalyst. Atomic force microscopy was proven suitable for investigating the PTFE distribution in the catalyst layer, which has a profound effect on the start-up and steady state performance of the cell

Formation of stable Si–O–C submonolayers on hydrogen-terminated silicon(111) under low-temperature conditions

• Yit Lung Khung,
• Siti Hawa Ngalim,
• Andrea Scaccabarozzi and
• Dario Narducci

Beilstein J. Nanotechnol. 2015, 6, 19–26, doi:10.3762/bjnano.6.3

• sensible explanation for this was that both Si–O–C and Si–C linkages were formed on the surface, thus creating a patchy surface with an intimate mixture of moieties exposing hydroxy or alkyne groups. This would certainly reduce the surface wettability as reported in previous reports on heterogeneous