Macroscopic adhesion-aggregation, floc formation, and subsequent transportation of microorganisms in porous media are closely related to the microscopic behavior and properties of individual cells. The classical Tabor's parameter in colloidal science is modified to correlate the macroscopic aggregation and microscopic adhesion properties of microorganisms. Seven bacterial strains relevant to wastewater treatment and bioremediation were characterized in terms of their macroscopic aggregation index (AI) using an optical method, and their microscopic coupled adhesion and deformation properties using atomic force microscopy (AFM). Single cells were indented to measure the range and magnitude of the repulsive-attractive intersurface forces, elastic modulus, thickness and density of the cellular surface substances (CSS). The strong correlation suggests that cost and time effective microscopic AFM characterization is capable of making reliable prediction of macroscopic behavior.
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http://dx.doi.org/10.1016/j.jcis.2012.01.032 | DOI Listing |
Materials (Basel)
January 2025
College of Civil Engineering and Architecture, Shandong University of Science and Technology, Qingdao 266590, China.
To investigate the water damage at the interface between emulsified asphalt and aggregate under the action of external water infiltration, firstly, cetyltrimethylammonium bromide was used as an emulsifier to prepare emulsified asphalt in the laboratory, and its basic properties were tested. Then, based on molecular dynamics, an emulsified asphalt-aggregate interface model with different water contents was constructed to calculate the adhesion work of the emulsified asphalt-aggregate interface. The results show that the simulated values of emulsified asphalt density, cohesive energy density, and solubility are in good agreement with the experimental values.
View Article and Find Full Text PDFSoft Matter
January 2025
Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61801, USA.
Linking the macroscopic flow properties and nanoscopic structure is a fundamental challenge to understanding, predicting, and designing disordered soft materials. Under small stresses, these materials are soft solids, while larger loads can lead to yielding and the acquisition of plastic strain, which adds complexity to the task. In this work, we connect the transient structure and rheological memory of a colloidal gel under cyclic shearing across a range of amplitudes a generalized memory function using rheo-X-ray photon correlation spectroscopy (rheo-XPCS).
View Article and Find Full Text PDFSci Rep
January 2025
Raw Building Materials Technology and Processing Research Institute, Housing & Building National Research Center, HBRC, Cairo, Egypt.
Fabrication of heavy density mortar using aggregates reinforced with available solid inorganic chemical additives is of a great importance as a protective layer to mitigate radiations in nuclear facilities. The effect of lead oxide and borax decahydrate on the hydration kinetics was evaluated by determining setting time, leachability and compressive strength. To speed up the reaction, 0.
View Article and Find Full Text PDFACS Nano
January 2025
School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Guangdong 518172, P.R. China.
Helical structures such as right-handed double helix for DNA and left-handed α-helix for proteins in biological systems are inherently chiral. Importantly, chirality at the nanoscopic level plays a vital role in their macroscopic chiral functionalities. In order to mimic the structures and functions of natural chiral nanoarchitectures, a variety of chiral nanostructures obtained from artificial helical polymers are prepared, which can be directly observed by atomic force microscopy (AFM), scanning tunneling microscopy (STM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM).
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Department of Chemistry, University of Hull, Hull HU6 7RX, UK. Electronic address:
Circular dichroism mapping (CDM) method was introduced by utilizing the highly collimated light beam of synchrotron radiation (SR) available at Diamond Light Source B23 beamline for scanning the thin films of the N phase. We apply SR-CDM to two achiral dimeric materials exhibiting the N phase: symmetric DTC5C9 and dissymmetric DTC5C9CB. The SR-CDM measurements directly capture the chiral information in the local N domains, providing the ultimate complement to the theoretical predictions of the helical structures: the spontaneous symmetry breaking in N phase is ambidextrous.
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