In this research, biocomposite films containing chitosan (CS), polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP), with different ratios, have been provided. The effects of adding hexamethylene 1, 6-di(aminocarboxysulfonate) (HMDACS) as cross-linking agent and the formation of urethane linkage on mechanical properties such as tensile strength, elongation and dynamic-mechanical properties such as storage modulus and tan δ were studied. Also, the antibacterial properties of the composites were investigated by viable bacterial cell counting and compared in reducing the bacterial growth. The final results showed the composite containing CS (50 wt%), PVA (30 wt%), PVP (20 wt%) and HMDACS (2 wt%) had the highest mechanical properties. Scanning electron microscopy (SEM) micrographs confirmed uniform distribution of components in the polymer matrix. In general, low contact angle values revealed the hydrophilicity of the prepared films. It was found that the composites made by combining CS, PVA and PVP at concentration of 50, 25, 25 wt% (A3) and 60, 20, 20 wt% (B4), cross-linked with 2 wt% HMDACS, had the best antibacterial activity against Escherichia coli and Staphylococcus aureus, hence they can be used as promising materials for the preparation of wound dressings.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.carbpol.2019.115606 | DOI Listing |
Phys Rev Lett
December 2024
National University of Singapore, Department of Physics, Singapore 117551.
We uncover emergent universality arising in the equilibration dynamics of multimode continuous-variable systems. Specifically, we study the ensemble of pure states supported on a small subsystem of a few modes, generated by Gaussian measurements on the remaining modes of a globally pure bosonic Gaussian state. We find that beginning from highly entangled, complex global states, such as random Gaussian states and product squeezed states coupled via a deep array of linear optical elements, the induced ensemble attains a universal form, independent of the choice of measurement basis: it is composed of unsqueezed coherent states whose displacements are distributed normally and isotropically, with variance depending on only the particle-number density of the system.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Quantinuum, 303 S. Technology Court, Broomfield, Colorado 80021, USA.
Although quantum mechanics underpins the microscopic behavior of all materials, its effects are often obscured at the macroscopic level by thermal fluctuations. A notable exception is a zero-temperature phase transition, where scaling laws emerge entirely due to quantum correlations over a diverging length scale. The accurate description of such transitions is challenging for classical simulation methods of quantum systems, and is a natural application space for quantum simulation.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Duke University, Department of Physics, Durham, North Carolina 27708, USA.
The emergence of a quantum spin liquid (QSL), a state of matter that can result when electron spins are highly correlated but do not become ordered, has been the subject of a considerable body of research in condensed matter physics [1,2]. Spin liquid states have been proposed as hosts for high-temperature superconductivity [3] and can host topological properties with potential applications in quantum information science [4]. The excitations of most quantum spin liquids are not conventional spin waves but rather quasiparticles known as spinons, whose existence is well established experimentally only in one-dimensional systems; the unambiguous experimental realization of QSL behavior in higher dimensions remains challenging.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
CERN, Geneva, Switzerland.
Z boson events at the Large Hadron Collider can be selected with high purity and are sensitive to a diverse range of QCD phenomena. As a result, these events are often used to probe the nature of the strong force, improve Monte Carlo event generators, and search for deviations from standard model predictions. All previous measurements of Z boson production characterize the event properties using a small number of observables and present the results as differential cross sections in predetermined bins.
View Article and Find Full Text PDFMater Horiz
January 2025
School of Chemistry, UNSW Sydney, Sydney, NSW 2052, Australia.
Patterning soft materials with cell adhesion motifs can be used to emulate the structures found in natural tissues. While patterning in tissue is driven by cellular assembly, patterning soft materials in the laboratory most often involves light-mediated chemical reactions to spatially control the presentation of cell binding sites. Here we present hydrogels that are formed with two responsive crosslinkers-an anthracene-maleimide adduct and a disulfide linkage-thereby allowing simultaneous or sequential patterning using force and UV light.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!