Nanocomposite materials were obtained from a colloidal suspension of chitin whiskers as the reinforcing phase and latex of both unvulcanized and prevulcanized natural rubber as the matrix. The chitin whiskers, prepared by acid hydrolysis of chitin from crab shell, consisted of slender parallelepiped rods with an aspect ratio close to 16. After the two aqueous suspensions were mixed and strirred, solid composite films were obtained either by freeze-drying and hot-pressing or by casting and evaporating the preparations. The processing and swelling behavior of composite films were evaluated. It was concluded that the whiskers form a rigid network assumed to be governed by a percolation mechanism in the evaporated samples only. Comparatively, better resistance of evaporated samples than hot-pressed ones against swelling in an organic solvent medium is good evidence for the existence of a rigid chitin network. The values of diffusion coefficient, bound rubber content, and relative weight loss also supported the presence of a three-dimensional chitin network within the evaporated samples. The mechanical behavior of the composites gives additional insight and evidence for this fact (part 2).
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http://dx.doi.org/10.1021/bm020127b | DOI Listing |
Nature
January 2025
Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.
Evaporation or freezing of water-rich fluids with dilute concentrations of dissolved salts can produce brines, as observed in closed basins on Earth and detected by remote sensing on icy bodies in the outer Solar System. The mineralogical evolution of these brines is well understood in regard to terrestrial environments, but poorly constrained for extraterrestrial systems owing to a lack of direct sampling. Here we report the occurrence of salt minerals in samples of the asteroid (101955) Bennu returned by the OSIRIS-REx mission.
View Article and Find Full Text PDFWaste Manag
January 2025
Department of Materials Science and Engineering, University of Seoul, Seoul 02504, South Korea. Electronic address:
This study investigates zone melting (ZM) as an innovative method for recycling 7000 series aluminum alloy scraps, a byproduct of computer numerical control (CNC) machining in smartphone production. Traditional fluxing methods are ineffective at removing Zn, a key alloying element. Vacuum atmospheric ZM utilizes the evaporation of Zn and Mg impurities and solidification segregation to concentrate elemental impurities within the melt, facilitating their efficient removal.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Atomic and Molecular Physics, Manipal Academy of Higher Education, Manipal 576104, India.
Slippery liquid-infused porous surfaces (SLIPSs) are a class of surface that offers low contact angle hysteresis and low tilt angle for water droplet shedding. This property also endows the surface with pinning-free evaporation, which in turn has been exploited for analyte concentration enrichment for Surface Enhanced Raman Spectroscopic applications and antibiofouling. Herein, we demonstrate a facile approach for creating SLIPS with low contact angle hysteresis and low tilt angle for water shedding by coating the equal-volume mixture of polydimethylsiloxane (PDMS) and silicone oil.
View Article and Find Full Text PDFJ Food Sci Technol
January 2025
Food Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhawan, 31, Mahatma Gandhi Marg, Lucknow, Uttar Pradesh 226001 India.
Unlabelled: Solid phase extraction technique is a widely used sample preparation technique for the extraction of components from complex food matrices. However, there are several parameters in SPE that leads to low recovery, and reproducibility, insufficiently clean extracts and evaporation of volatile compounds. These drawbacks can be addressed through the use of innovative techniques and instrumentation that offers improved efficiency and accuracy for isolation of active constituents from food and beverage samples.
View Article and Find Full Text PDFFront Plant Sci
January 2025
Department of Biology, University of Mississippi, University, MS, United States.
Temperature control is crucial for live cell imaging, particularly in studies involving plant responses to high ambient temperatures and thermal stress. This study presents the design, development, and testing of two cost-effective heating devices tailored for confocal microscopy applications: an aluminum heat plate and a wireless mini-heater. The aluminum heat plate, engineered to integrate seamlessly with the standard 160 mm × 110 mm microscope stage, supports temperatures up to 36°C, suitable for studies in the range of non-stressful warm temperatures (e.
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