Recently, fiber-reinforced, epoxy-based, optically transparent composites were successfully produced using resin transfer molding (RTM) techniques. Generally, the production of structural, optically transparent composites is challenging since it requires the combination of a very smooth mold surface with a sufficient control of resin flow that leads to no visible voids. Furthermore, it requires a minimum deviation of the refractive indices (RIs) of the matrix polymer and the reinforcement fibers. Here, a new mold design is described and three plates of optically transparent glass fiber-reinforced polymers (tGFRP) with reproducible properties as well as high fiber volume fractions were produced using the RTM process and in situ polymerization of an epoxy resin system enclosing E-glass fiber textiles. Their mechanical (flexural), microstructural (fiber volume fraction, surface roughness, etc.), thermal (DSC, TGA, etc.), and optical (dispersion curves of glass fibers and polymer as well as transmission over visible spectra curves of the tGFRP at varying tempering states) properties were evaluated. The research showed improved surface quality and good transmission data for samples manufactured by a new Optical-RTM setup compared to a standard RTM mold. The maximum transmission was reported to be ≈74%. In addition, no detectable voids were found in these samples. Furthermore, a flexural modulus of 23.49 ± 0.64 GPa was achieved for the Optical-RTM samples having a fiber volume fraction of ≈42%.
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http://dx.doi.org/10.3390/polym15092183 | DOI Listing |
Clin Oral Investig
January 2025
School of Materials Science and Innovation, Faculty of Science, Mahidol University, Phuttamonthon 4 Road, Salaya, Phuttamonthon District, Nakhon Pathom, 73170, Thailand.
Objectives: To address the high surface roughness and poor optical properties of three-dimensional (3D) printed orthodontic clear retainers, an alternative post-processing protocol was investigated with the goal of achieving improved surface, optical, and mechanical properties while preserving dimensional accuracy.
Materials And Methods: Samples were prepared from two biocompatible methacrylate-based 3D-printing resins (Formlabs Dental LT Clear V2, NextDent OrthoFlex) and one thermoplastic material (Duran). For the 3D-printed resins, one group was post-processed by rinsing in isopropyl alcohol, while another group was centrifuged before post-curing in glycerine.
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
Anhembi Morumbi University (UAM), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil; Center of Innovation, Technology and Education (CITE), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil. Electronic address:
The inherent potential for self-assembly is a well-known attribute of organic dye molecules. This work takes advantage of the changes in dye photochemical and photophysical properties produced by the aggregation phenomenon, to investigate the behavior of all-optical modulation in molecular aggregates. The theoretical principles for a dual beam all-optical modulation, as well as the conception of an optical logic gate by exploring the aggregation phenomenon are discussed throughout the article.
View Article and Find Full Text PDFPhys Med Biol
January 2025
Schlegel Research Institute for Aging, University of Waterloo, 250 Laurelwood Drive, Waterloo, Ontario, N2L 3G1, CANADA.
As ultrasound-compatible flow phantoms are devised for performance testing and calibration, there is a practical need to obtain independent flow measurements for validation using a gold-standard technique such as particle image velocimetry (PIV). In this paper, we present the design of a new dual-modality flow phantom that allows ultrasound and PIV measurements to be simultaneously performed. Our phantom's tissue mimicking material is based on a novel hydrogel formula that uses propylene glycol to lower the freezing temperature of an ultrasound-compatible poly(vinyl) alcohol cryogel and, in turn, maintain the solution's optical transparency after thermocycling.
View Article and Find Full Text PDFJ Chem Phys
January 2025
School of Physics and Astronomy, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China.
Two-dimensional electronic spectroscopy (2DES) has high spectral resolution and is a useful tool for studying atomic dynamics. In this paper, we show a smallest unit of electromagnetically induced transparency (EIT) for 2DES, i.e.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Materials, Shenzhen Campus of Sun Yat-sen University, No. 66, Gongchang Road, Guangming District, Shenzhen, Guangdong 518107, P.R. China.
Indium (In) reduction is a hot topic in transparent conductive oxide (TCO) research. So far, most strategies have been focused on reducing the layer thickness of In-based TCO films and exploring TCOs. However, no promising industrial solution has been obtained yet.
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