Films and sponges were prepared from a solution of Poly(epsilon-caprolactone) (PCL) in tetrahydrofuran (THF). The porosity, crystallinity, and mechanical properties of the samples were studied. Porosity of around 15% was obtained for the films produced by evaporation of THF at room temperature. A much more porous structure (50-70%) was found for the sponges obtained by cooling the solution at -30 degrees C and subsequently eliminating the solvent by freeze drying. The porosity of the samples was also observed by scanning electron microscopy (SEM). The crystallinity of the samples was studied by the calorimetric technique (DSC) before and after the compression scans. The mechanical properties of the different samples were determined by compression test, and were compared to those corresponding to the PCL in bulk. The compression scans did not affect the crystallinity of the samples. The variations observed in the results of the different scans were attributed to the differences in porosities and crystallinity.
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http://dx.doi.org/10.1007/s10856-006-0101-2 | DOI Listing |
Macromol Rapid Commun
January 2025
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China.
Functional fibrous membranes with high mechanical properties are intensively developed for different application fields. In this study, to enhance moisture and air permeability without compromising mechanical strength, a facile float-surface modification strategy is employed to fabricate Janus fibrous membranes with distinct hydrophobicity/hydrophilicity using the high-density polyethylene (HDPE) fibrous membranes. By coating one side of the HDPE fibrous membranes with polydopamine (PDA) and a superhydrophilic polyelectrolyte, the obtained Janus HDPE fibrous membranes demonstrate an excellent water transmission rate (577.
View Article and Find Full Text PDFJ Esthet Restor Dent
January 2025
Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Kiel, Germany.
Objective: Investigation of the mechanical properties of occlusal veneers made from zirconia with varying translucency, bonded to different tooth substrates.
Materials And Methods: Sixty-four extracted molars were divided into two groups: preparation within enamel (E) or extending into dentin (D). Veneers were milled from four zirconia ceramics (n = 8): 5Y-TZP (HT), a multilayer of 5 and 3Y-TZP (GT), 3Y-TZP (LT), and 4Y-TZP (MT).
ACS Nano
January 2025
Dto. de Física de Materiales, Universidad Complutense de Madrid, 28040 Madrid, Spain.
We experimentally observe quantum confinement states in bulk MoS by using angle-resolved photoemission spectroscopy (ARPES). The band structure at the Γ̅ point reveals quantum well states (QWSs) linked to vertical quantum confinement of the electrons, confirmed by the absence of dispersion in and a strong intensity modulation with the photon energy. Notably, the binding energy dependence of the QWSs versus does not follow the quadratic dependence of a two-dimensional electron gas.
View Article and Find Full Text PDFInt J Surg
January 2025
Department of Pathology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
The immune response is modulated by a diverse array of signals within the tissue microenvironment, encompassing biochemical factors, mechanical forces, and pressures from adjacent tissues. Furthermore, the extracellular matrix and its constituents significantly influence the function of immune cells. In the case of carcinogenesis, changes in the biophysical properties of tissues can impact the mechanical signals received by immune cells, and these signals can be translated into biochemical signals through mechano-transduction pathways.
View Article and Find Full Text PDFNatl Sci Rev
January 2025
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.
Two-dimensional (2D) van der Waals (vdW) materials are known for their intriguing physical properties, but their rational design and synthesis remain a great challenge for chemists. In this work, we successfully synthesized a new non-centrosymmetric oxide, i.e.
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