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1. Interfacial cavitation

   https://doi.org/10.1093/pnasnexus/pgac217  

   Henzel, Thomas; Nijjer, Japinder; Chockalingam, S.; Wahdat, Hares; Crosby, Alfred J.; Yan, Jing; Cohen, Tal; Grest, ed., Gary (October 2022, PNAS Nexus)

   Abstract Cavitation has long been recognized as a crucial predictor, or precursor, to the ultimate failure of various materials, ranging from ductile metals to soft and biological materials. Traditionally, cavitation in solids is defined as an unstable expansion of a void or a defect within a material. The critical applied load needed to trigger this instability -- the critical pressure -- is a lengthscale independent material property and has been predicted by numerous theoretical studies for a breadth of constitutive models. While these studies usually assume that cavitation initiates from defects in the bulk of an otherwise homogeneous medium, an alternative and potentially more ubiquitous scenario can occur if the defects are found at interfaces between two distinct media within the body. Such interfaces are becoming increasingly common in modern materials with the use of multimaterial composites and layer-by-layer additive manufacturing methods. However, a criterion to determine the threshold for interfacial failure, in analogy to the bulk cavitation limit, has yet to be reported. In this work, we fill this gap. Our theoretical model captures a lengthscale independent limit for interfacial cavitation, and is shown to agree with our observations at two distinct lengthscales, via two different experimental systems. To further understand the competition between the two cavitation modes (bulk versus interface), we expand our investigation beyond the elastic response to understand the ensuing unstable propagation of delamination at the interface. A phase diagram summarizes these results, showing regimes in which interfacial failure becomes the dominant mechanism. 

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2. Excitation of interfacial waves via surface–interfacial wave interactions

   https://doi.org/10.1017/jfm.2019.1033  

   Zaleski, Joseph; Zaleski, Philip; Lvov, Yuri V. (March 2020, Journal of Fluid Mechanics)

   We consider interactions between surface and interfacial waves in a two-layer system. Our approach is based on the Hamiltonian structure of the equations of motion, and includes the general procedure for diagonalization of the quadratic part of the Hamiltonian. Such diagonalization allows us to derive the interaction cross-section between surface and interfacial waves and to derive the coupled kinetic equations describing spectral energy transfers in this system. Our kinetic equation allows resonant and near-resonant interactions. We find that the energy transfers are dominated by the class III resonances of Alam ( J. Fluid Mech. , vol. 691, 2012, pp. 267–278). We apply our formalism to calculate the rate of growth for interfacial waves for different values of wind velocity. Using our kinetic equation, we also consider the energy transfer from wind-generated surface waves to interfacial waves for the case when the spectrum of the surface waves is given by the JONSWAP spectrum and interfacial waves are initially absent. We find that such energy transfer can occur along a time scale of hours; there is a range of wind speeds for the most effective energy transfer at approximately the wind speed corresponding to white capping of the sea. Furthermore, interfacial waves oblique to the direction of the wind are also generated. 

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3. Comparing Interfacial Trp, Interfacial His and pH Dependence for the Anchoring of Tilted Transmembrane Helical Peptides

   https://doi.org/10.3390/biom10020273  

   Afrose, Fahmida; Koeppe II, Roger E. (February 2020, Biomolecules)

   Charged and aromatic amino acid residues, being enriched toward the terminals of membrane-spanning helices in membrane proteins, help to stabilize particular transmembrane orientations. Among them, histidine is aromatic and can be positively charge at low pH. To enable investigations of the underlying protein-lipid interactions, we have examined the effects of single or pairs of interfacial histidine residues using the constructive low-dynamic GWALP23 (acetyl-GG2ALW5LALALALALALALW19LAG22A-amide) peptide framework by incorporating individual or paired histidines at locations 2, 5, 19 or 22. Analysis of helix orientation by means of solid-state 2H NMR spectra of labeled alanine residues reveals marked differences with H2,22 compared to W2,22. Nevertheless, the properties of membrane-spanning H2,22WALP23 helices show little pH dependence and are similar to those having Gly, Arg or Lys at positions 2 and 22. The presence of H5 or H19 influences the helix rotational preference but not the tilt magnitude. H5 affects the helical integrity, as residue 7 unwinds from the core helix; yet once again the helix orientation and dynamic properties show little sensitivity to pH. The overall results reveal that the detailed properties of transmembrane helices depend upon the precise locations of interfacial histidine residues. 

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4. Generalization of interfacial thermal conductance based on interfacial phonon localization

   https://doi.org/10.1016/j.mtphys.2024.101516  

   Al_Keyyam, Ibrahim; Wang, Xinwei (August 2024, Materials Today Physics)
5. The role of the plasmon in interfacial charge transfer

   https://doi.org/10.1126/sciadv.adp3353  

   Ostovar, Behnaz; Lee, Stephen A; Mehmood, Arshad; Farrell, Kieran; Searles, Emily K; Bourgeois, Briley; Chiang, Wei-Yi; Misiura, Anastasiia; Gross, Niklas; Al-Zubeidi, Alexander; et al (July 2024, Science Advances)

   The lack of a detailed mechanistic understanding for plasmon-mediated charge transfer at metal-semiconductor interfaces severely limits the design of efficient photovoltaic and photocatalytic devices. A major remaining question is the relative contribution from indirect transfer of hot electrons generated by plasmon decay in the metal to the semiconductor compared to direct metal-to-semiconductor interfacial charge transfer. Here, we demonstrate an overall electron transfer efficiency of 44 ± 3% from gold nanorods to titanium oxide shells when excited on resonance. We prove that half of it originates from direct interfacial charge transfer mediated specifically by exciting the plasmon. We are able to distinguish between direct and indirect pathways through multimodal frequency-resolved approach measuring the homogeneous plasmon linewidth by single-particle scattering spectroscopy and time-resolved transient absorption spectroscopy with variable pump wavelengths. Our results signify that the direct plasmon-induced charge transfer pathway is a promising way to improve hot carrier extraction efficiency by circumventing metal intrinsic decay that results mainly in nonspecific heating. 

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