Colorimetric gas detection by the varying thickness of a thin film of ultrasmall PTSA-coated TiO₂ nanoparticles on a Si substrate

• Urmas Joost,
• Andris Šutka,
• Meeri Visnapuu,
• Aile Tamm,
• Meeri Lembinen,
• Mikk Antsov,
• Kathriin Utt,
• Krisjanis Smits,
• Ergo Nõmmiste and
• Vambola Kisand

Beilstein J. Nanotechnol. 2017, 8, 229–236, doi:10.3762/bjnano.8.25

• concentrations of ethanol/water mixtures into the Petri dish located near the sample. In the TiO2 NP-based thin films, the incident light is, in part, reflected back from the air/film interface and, in part, from the substrate surface and the light waves interfere. The position of the maxima and minima of

• interference depends on the optical path length difference of the light reflected from the air/film and film/substrate interfaces. This difference is determined by film thickness and refractive index [11]. When VOC molecules are absorbed in NP-based film, swelling occurs, and the optical path length of the

Counterion effects on nano-confined metal–drug–DNA complexes

• Nupur Biswas,
• Sreeja Chakraborty,
• Alokmay Datta,
• Munna Sarkar,
• Mrinmay K. Mukhopadhyay,
• Mrinal K. Bera and
• Hideki Seto

Beilstein J. Nanotechnol. 2016, 7, 62–67, doi:10.3762/bjnano.7.7

• density for the element Cu, where . The difference in electron densities, represents the abundance of Cu. Figure 4a shows this variation along the film depth for both films. We observe a relative abundance of Cu near the air–film interface suggesting a Cu-rich upper layer for both films. This effect is

Aquatic versus terrestrial attachment: Water makes a difference

• Petra Ditsche and
• Adam P. Summers

Beilstein J. Nanotechnol. 2014, 5, 2424–2439, doi:10.3762/bjnano.5.252

• surfaces [68][72]. Many superhydrophobic surfaces are known for their ability to hold an air film under water for a varying time span [73][74][75]. Therefore, these surfaces could hold micro bubbles that serve as cavitation nucleating sites as in seawater. Whether this effect would occur after a long-time

Measuring air layer volumes retained by submerged floating-ferns Salvinia and biomimetic superhydrophobic surfaces

• Matthias J. Mayser,
• Holger F. Bohn,
• Meike Reker and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2014, 5, 812–821, doi:10.3762/bjnano.5.93

• pocket, which is considerably smaller than an air film with full height on those surfaces. Still the correction of the measured volumes with the hair volumes and air–water interface shape influence reduced the difference between this value and the theoretically calculated one by more than the factor of

Superhydrophobic surfaces of the water bug Notonecta glauca: a model for friction reduction and air retention

• Petra Ditsche-Kuru,
• Erik S. Schneider,
• Jan-Erik Melskotte,
• Martin Brede,
• Alfred Leder and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 137–144, doi:10.3762/bjnano.2.17

• biomimetic applications. Whereas the self-cleaning properties of superhydrophobic surfaces have been extensively investigated, their ability to retain an air film while submerged under water has not, in the past, received much attention. Nevertheless, air retaining surfaces are of great economic and

• ecological interest because an air film can reduce friction of solid bodies sliding through the water. This opens perspectives for biomimetic applications such as low friction fluid transport or friction reduction on ship hulls. For such applications the durability of the air film is most important. While

• the air film on most superhydrophobic surfaces usually lasts no longer than a few days, a few semi-aquatic plants and insects are able to hold an air film over a longer time period. Currently, we found high air film persistence under hydrostatic conditions for the elytra of the backswimmer Notonecta