Looking Thru the Nano Lens: Art, Science and Nature

In 2018, an interdisciplinary team of researchers from the School of Chemistry, Sydney Nano and the Department of Art History at the University of Sydney set up a pilot project called the Nano Lens. Our project set out to examine and experiment with what it means to look closely at the natural world and inviting us, as colleagues, into a discussion and collaboration, drawing on our different perspectives. The Nano Lens also gave agency to a group of scientists in training (undergraduate and postgraduate students), and a sense of ownership of the science, which was then transmitted to the public. Taking inspiration from the artwork of the prominent Australian painter Margaret Preston (1875-1963) and the flora she depicted, the Nano Lens has opened up new research that intersects science and the arts; celebrating the value of collaboration and offering opportunities for staff and students to engage in and lead interdisciplinary discussions with the public. This paper will discuss our pilot project and the initial findings of our research together and discuss the benefits that our alliance has had in fostering collaboration and outreach activities where academics and students work together to share their research with the public. We seek to reflect on what we have learnt from the project and from opportunities to share our work and approaches. What does it mean to look like a scientist or to look like an artist and how has this enriched student learning? What value is there in opening up opportunities for informal learning about science and collaboration outside your disciplines

Effect of Pore Size, Lubricant Viscosity, and Distribution on the Slippery Properties of Infused Cement Surfaces

The fabrication of slippery liquid-infused porous surfaces (SLIPS) usually requires the use of structured substrates, with specifically designed micro- and nanoroughness and complementary surface chemistry, ideally suited to trap lubricants. It is not yet established whether a random roughness, with a range of pores with a variable size reaching deep into the bulk of the material, is suitable for successful infusion. In this study, a highly porous material with random and complex roughness, obtained by using portland cement (the most common type of cementitious material), was tested for its potential to act as a SLIP surface. Atomic force microscopy meniscus measurements were used to investigate the distribution of lubricants on the surface upon subsequent stages of depletion because of the capillary absorption of the lubricant within the porous structure. Factors such as curing time of the cement paste, time since infusion, and lubricant viscosity were varied to identify the conditions under which infusion could be considered successful. A sensitive method to evaluate the penetration of liquid (low-temperature differential scanning calorimetry) was used, which could be applicable to many porous materials. The optimized infusion of cement surfaces ultimately resulted in the desired hallmarks of SLIPS, that is, high water repellence and slipperiness, effective for several weeks, reduced water permeability, and icephobicity

Functional Selectivity Does Not Predict Antinociceptive/Locomotor Impairing Potencies of NOP Receptor Agonists

Nociceptin/orphanin FQ controls several functions, including pain transmission, via stimulation of the N/OFQ peptide (NOP) receptor. Here we tested the hypothesis that NOP biased agonism may be instrumental for identifying innovative analgesics. In vitro experiments were performed with the dynamic mass redistribution label free assay and the NOP non-peptide agonists Ro 65-6570, AT-403 and MCOPPB. In vivo studies were performed in wild type and β-arrestin 2 knockout mice using the formalin, rotarod and locomotor activity tests. In vitro all compounds mimicked the effects of N/OFQ behaving as potent NOP full agonists. In vivo Ro 65-6570 demonstrated a slightly higher therapeutic index (antinociceptive vs. motor impairment effects) in knockout mice. However, all NOP agonists displayed very similar therapeutic index in normal mice despite significant differences in G protein biased agonism. In conclusion the different ability of inducing G protein vs. β-arrestin 2 recruitment of a NOP agonist cannot be applied to predict its antinociceptive vs. motor impairment properties

Slightly Depleted Lubricant-Infused Surfaces Are No Longer Slippery

Textured surfaces infused with a lubricating fluid effectively reduce fouling and drag. These functions critically depend on the presence and distribution of the lubricant, which can be depleted by many mechanisms, including shear flow. We present a two-phase Couette flow computational dynamic simulation over lubricant-infused surfaces containing grooves oriented perpendicular to the flow direction, with the aim of revealing how interfacial slip, and therefore drag reduction, is impacted by lubricant depletion. We show that even a slight (20%) lubricant loss decreases slip to the point of making the lubricant superfluous, even for lubricants with lower viscosity than the flowing liquid and regardless of how well the lubricant wets the grooves. We explain that the drastic slip reduction is linked to a significant increase in the total viscous dissipation and to zero dissipation in the lubricant (similar to the one given by a no-slip boundary)

Pressure drop measurements in microfluidic devices: a review on the accurate quantification of interfacial slip

The correct theoretical definition of boundary conditions of flow underpins all fluid dynamics studies, and is particularly important in situations in which the flow is confined on the nano- and micro-scale. Microfluidic devices are an excellent platform to measure boundary flow conditions, and the pressure drop versus flow rate method is particularly useful in detecting evidence of microscale interfacial slip and drag reduction. This review focuses on the pressure drop method, identifying the main experimental parameters affecting the accuracy and reproducibility of microfluidic experiments of slip, quantifying the magnitude and source of common errors, and providing practical solutions and guidelines. A summary of literature results of interfacial slip obtained with pressure drop measurements in microfluidic devices is also provided, and the slip results are directly compared to expected slip models. This review serves as an introduction for new researchers moving into the field of interfacial slip, and as reminder for established researchers of the need to create highly controlled experimental procedures in order to obtain reproducible and reliable measurements of boundary flow conditions. A direct comparison of accurate experiments with theoretical models is bound to bring about clarity about the mechanisms of slip on smooth and structured surfaces

Mechanical properties of Ropaque hollow nanoparticles

The elastic properties and strength upon compression of commercial Ropaque polystyrene hollow particles were investigated by atomic force microscopy (AFM). These particles are commonly used in paints as opacifying agents, as their internal air void effectively scatters light. A sharp AFM tip was used to apply a point load to the particle surface, and increased to probe both the elastic and plastic deformation of the shell, and then further until the shell broke. For small deformations, the deformation increased linearly with applied force. The Young’s modulus was calculated by accounting for the effect of the rigid substrate, and compare the modulus obtained from the Reissner and Hertz models. The minimum stress needed to destroy the integrity of the shell was extracted and found to be smaller than or close to that of silica hollow particles with different shell thickness tested in the literature.Australian Research Council and DuluxGroup Australia through Linkage gran

Detection of Nanobubbles on Lubricant-Infused Surfaces Using AFM Meniscus Force Measurements

So far, the presence of nanobubbles on lubricant-infused surfaces (LIS) has been overlooked, because of the difficulty in detecting them in such a complex system. We recently showed that anomalously large interfacial slip measured on LIS is explained by the presence of nanobubbles [Vega-Sánchez, Peppou-Chapman, Zhu and Neto, Nat. Commun., 2022 13, 351]. Crucial to drawing this conclusion was the use of atomic force microscopy (AFM) force− distance spectroscopy (meniscus force measurements) to directly image nanobubbles on LIS. This technique provided vital direct evidence of the spontaneous nucleation of nanobubbles on lubricantinfused hydrophobic surfaces. In this paper, we describe in detail the data collection and analysis of AFM meniscus force measurements on LIS and show how these powerful measurements can quantify both the thickness and distribution of multiple coexisting fluid layers (i.e., gas and oil) over a nanostructured surface. Using this technique, thousands of force curves were automatically analyzed. The results show that the interfacial tension of the nanobubbles is reduced from 52 ± 9 mN m−1 to 39 ± 4 mN m−1 by the presence of the silicone oil layer

EVANDO NASCIMENTO: “Não desprezo o mercado, isso seria ingênuo, mas creio que a relação deve ser sempre crítica e desconfiada, sob o risco de trituração pela máquina”.

Evando Nascimento respondeu as perguntas de seus quatro interlocutores por escrito, na ordem em que foram chegando, invariavelmente com erudição e inteligência. A incrível marca de dezenas de laudas se soma ao aspecto de alentado memorial para fazer pensar que o autor colocou em xeque mais um gênero, agora para caracterizar plenamente a entrevista como literária.As pesquisas e análises -- como aquelas que renderam livros dedicados, respectivamente, a Clarice Lispector e Jacques Derrida --, a coordenação da Coleção Contemporânea, o hábito de escrever bem mais do que publica, o desenraizamento como meio caminho para o cosmopolitismo, tudo é matéria de uma constelação temática que, abordada com didatismo e dissecada em bom texto, configura-se um todo articulado e resplandecente