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Abstract: A modified chitosan transparent thin membrane (MCTTM) was prepared and used as the adsorbent to investigate the adsorption kinetics due to excellent capacity of removing copper ions in water solution. The structure and morphology of MCTTM were characterized by SEM analysis and FTIR analysis. External mass transfer, intra particle diffusion, and pseudo-first and pseudo-second order models were used to describe the adsorption process. The results obtained from the study illustrated that the adsorption process could be described by the pseudo-second order model, which indicated adsorption process was a chemical adsorption behavior of chelation ion exchange proved by the FTIR and adsorption free energy analysis. External mass transfer and intra particle diffusion processes were the rate-controlling steps. [ABSTRACT FROM AUTHOR]

[Display omitted] • The auxiliary cementitious materials can effectively fill the micropores and shorten the interfacial transition zone. • The developed elastoplastic parallel bonding model can record the irreversible damage during freeze–thaw cycles. • The decay constants of UCS and elastic modulus after freeze–thaw cycles can be estimated from the initial parameters. In this paper, pervious concrete (PC) was prepared using fly ash, granulated blast furnace slag, and rice husk ash as supplementary cementitious materials (SCMs), and the mechanical properties, water permeability, and freeze–thaw durability of permeable concrete were mainly investigated. Discrete elements (DEM) were used to mimic the freeze–thaw cycle process of pervious concrete to assess better how freeze–thaw cycles affect the mechanical properties of pervious concrete. To allow water particles of various sizes to fill the model pores, new algorithms were developed. However, since some connected pores release some of the pressure generated by water expansion when undergoing FTCs, two different water particles must be defined. Meanwhile, an elastoplastic parallel bond contact model (EPPBM) was created to account for any residual strain brought on by water freeze–thaw expansion at the aggregate bond. Through experiments, it was determined that adding SCMs increased the compressive strength of the pervious concrete by 1.22 %, 15.32 %, 32.34 %, and 35.20 % at 7, 28, 56, and 90 days compared to the control group. The microstructure of the hydrated calcium silicate (C-S-H) gel could be relatively dense by SEM. The width of the interfacial transition zone (ITZ) was found to have been effectively shortened by further scanning using EDS. As a result, in the tests of mechanical properties after freeze–thaw cycles (25, 50, 75, and 100 cycles), there was a significant improvement in the loss of strength compared to the control group, which was 2.13 %, 6.91 %, 10.04 %, and 17.40 %, respectively. Using numerical simulation to correct the functional correlation between FTCs and the mechanical characteristics of permeable concrete, the trend essentially aligns with the experiment's results, demonstrating the model's viability. Acoustic emission monitoring of model rupture location and strain energy loss after FTCs were utilized and the effect of different porosity and initial uniaxial compressive strength (UCS) on the attenuation constant of the freeze–thaw resistance of pervious concrete was analyzed. The decay constant of UCS increased with increasing porosity and elastic modulus while decreasing with increasing initial UCS. Therefore, the decay constant of UCS and elastic modulus after arbitrary FTCs can be easily estimated using the initial parameters of the pervious concrete. [ABSTRACT FROM AUTHOR]

Micropumps can generate directional microflows in blood vessels or bio-capillaries for targeted transport of nanoparticles and cells in vivo , which is highly significant for biomedical applications from active drug delivery to precision clinical therapy. Meanwhile, they have been extensively used in the biosensing fields with their unique features of autonomous motion, easy surface functionalization, dynamic capture and effective isolation of analytes in complex biological media. However, synthetic devices for actuating microflows, including pumps and motors, generally exhibit poor or limited biocompatibility with living organisms as a result of the invasive implantation of exogenous materials into blood vessels. Here we demonstrate a method of constructing endogenous micropumps by extracting nuclei from red blood cells, thus making them intrinsically and completely biocompatible. The nuclei are extracted and then driven by a scanning optical tweezing system. By a precise actuation of the microflows, nanoparticles and cells are navigated to target destinations, and the transport velocity and direction is controlled by the multifunctional dynamics of the micropumps. With the targeted transport of functionalized micro/nanoparticles followed by a dynamic mixing in microliter blood samples, the micropumps provide considerable promises to enhance the target binding efficiency and improve the sensitivity and speed of biological assays in vivo. Furthermore, multiplexing by simultaneously driving an array of multiple nuclei is demonstrated, thus confirming that the micropumps could provide a bio-friendly high-throughput in vivo platform for the treatment of blood diseases, microenvironment monitoring, and biomedical analysis. • A light-driven micropump was constructed with endogenous cell nucleus to transport nanoparticles and cells in vivo. • The bio-friendly micropump was free from invasive implantation of exogenous matters and independent of particle composition. • Multifunctional dynamics of micropumps assured a real-time control of the transport velocity and directions. • A high-throughput platform can be accomplished by multiplexing an array of multiple nucleus micropumps. [ABSTRACT FROM AUTHOR]