What is the relationship between nano surface roughness and adhesion?5 answersNano surface roughness plays a crucial role in adhesion phenomena across various fields. Studies have shown that reducing the surface roughness of materials such as NiTi wires to nano-levels significantly decreases bacterial adhesion by over 70% to 83.48%. Conversely, the extent of bacterial fouling on hydrophobic surfaces can vary up to 75-fold with changes in surface roughness, with increased roughness enhancing adhesion on certain surfaces. Furthermore, nanoparticle roughness affects suspension stability, where small changes in roughness can significantly impact the phase behavior of suspensions, influencing adhesion forces and gel formation. Additionally, the adhesion hysteresis of Cu thin films is influenced by surface roughness, with smoother surfaces exhibiting more pronounced adhesion hysteresis. These findings collectively highlight the intricate relationship between nano surface roughness and adhesion in various material systems.
How does nanoparticle affect the mechanical property of bionano composite films?5 answersNanoparticles play a crucial role in enhancing the mechanical properties of bionanocomposite films. Studies have shown that the addition of nanoparticles like zinc oxide (ZnO-NPs), gallic acid (GA), and nanosilicates can improve the structural cohesion of biopolymer matrices, leading to increased tensile strength, elongation, and Young's elastic modulus. Specifically, the selective localization of nanoparticles at interfaces within the polymer blend can positively impact mechanical performance, such as deformation at break and barrier properties, by acting as reinforcements and compatibilizers. Moreover, the appropriate parameters of nanoparticles, such as size, concentration level, and morphology, significantly influence the mechanical characteristics of bionanocomposite films, ultimately improving properties like water vapor permeability, tensile strength, and elongation.
Why is nano labelling important?4 answersNano labelling is crucial due to its role in ensuring food safety, tracking nanoparticles in biological environments, and studying the behavior of nanoparticles in vitro and in vivo. Nanomaterials, including nanolabels, offer advantages like stability, low cost, and multi-category signal output, making them ideal for sensitive detection of biochemical targets in food contaminants. Labeling methods such as fluorescent, radiological, and metallic labeling are used to track engineered nanomaterials in complex biological matrices. Stable incorporation of dyes within nanoparticles is essential to avoid misinterpretation of biodistribution and cellular uptake, emphasizing the significance of reliable nano labelling techniques. Overall, nano labelling plays a critical role in various fields by enhancing detection sensitivity, ensuring accurate tracking, and facilitating comprehensive studies on nanoparticles.
Can continuum mechanics be applied in nano-scale structures?4 answersContinuum mechanics models can be applied to investigate the mechanical behavior of micro-/nano-structures. The use of classical theories in analyzing small-scale structures can lead to inaccurate results. Size-dependent theories, such as peridynamic theory and strain gradient theory, are more suitable for analyzing the mechanical characteristics of nano-scale structures. Peridynamic theory has advantages over classical continuum mechanics-based methods and molecular dynamic simulation methods, particularly in solving crack propagation problems. Strain gradient theory has been used to study the size effect phenomenon in nano-sized structures, where the mechanical response cannot be accurately modeled using classical continuum theories. These non-classical theories provide a more accurate understanding of the mechanical behavior of nano-scale structures and can be used to simulate and analyze their performance.
Is there any nanoindentation results and GB pop-in?5 answersNanoindentation results and grain boundary (GB) pop-ins are discussed in the literature. The occurrence of pop-ins during nanoindentation tests is attributed to the difficulty of setting up dislocation sources in the small indentation zones. The stress-strain curves obtained from spherical indentation tests show a high and stable indentation stress value during the pop-in event, with a decrease in stress only after further indentation displacement. The physical processes occurring underneath the indenter during and after the pop-in event are proposed to explain these observations. The effect of surface roughness on nanoindentation results is also studied, with the test being more sensitive to roughness compared to conventional hardness tests. The influence of other parameters, such as indenter rounding, shape, penetration depth, and wavelength of roughness, on test results is also investigated.
What is the nanostructure of porcelain?2 answersPorcelain has a nanostructured interface with polymer modified mortars, which is formed by hydrogen bonds between poly(vinyl alcohol) (PVA) hydroxyl groups, silanol from the tile surface, and water from the nanostructured C-S-H gel interlayer. The ceramic matrix of porcelain consists of nano-shaped fibrous structures, such as nano-lamellae as secondary particles.