The first stages of the synthesis of ZnO nanoparticles by forced hydrolysis of ZnCl2 with NaOH and water in ethanol have been investigated using UV-Vis spectrophotometry. At sufficiently low water concentrations, focusing of the nanoparticle size distribution was observed during the nucleation and growth phase, followed by a defocusing phase when coarsening becomes significant. During nucleation and growth, only the smaller particles grow while the larger particles have an essentially zero growth rate, indicating that the growth rate decreases rapidly with particle size. As the average particle size remains nearly constant in this regime, the absorbance increase with time can be used to determine the nucleation rate. The nucleation rate was found to depend on both the water concentration and the reactant concentrations. The results are discussed in terms of a mechanism where water determines the precursor formation kinetics thus controlling the nucleation rate.
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http://dx.doi.org/10.1039/c0nr00439a | DOI Listing |
Recent Pat Nanotechnol
January 2025
Ansteel Beijing Research Institute Co., Ltd., Beijing 102211, China.
Background: Sodium vanadium fluorophosphate is a sodium ion superconductor material with high sodium ion mobility and excellent cyclic stability, making it a promising cathode material for sodium-ion batteries. However, most of the literature and patents report preparation through traditional methods, which involve complex processes, large particle sizes, and low electronic conductivity, thereby limiting development progress.
Objective: Aiming at the limitation of high cost and poor performance of vanadium sodium fluorophosphate cathode material, the low temperature and high-efficiency nano preparation technology was developed.
Langmuir
January 2025
State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan 430072, China.
Mineral precipitation is ubiquitous in natural and engineered environments, such as carbon mineralization, contaminant remediation, and oil recovery in unconventional reservoirs. The precipitation process continuously alters the medium permeability, thereby influencing fluid transport and subsequent reaction kinetics. The diversity of preferential precipitation zones controls flow and transport efficiency as well as the capacity of mineral sequestration and immobilization.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Key Laboratory of Intelligent Textile and Flexible Interconnection of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China. Electronic address:
The environmental challenges linked to petroleum-based polymers have accelerated the search for alternative materials like polylactic acid (PLA). Diverse nanofillers, ranging from inorganic to organic and hybrid inorganic/organic varieties, are employed to bolster PLA performance. Yet, non-synergistic nanofillers often underperform due to inadequate dispersion and singular functionality within the PLA matrix.
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan.
(1) Background: Fetal chromosomal examination is a critical component of modern prenatal testing. Traditionally, maternal serum biomarkers such as free β-human chorionic gonadotropin (Free β-HCG) and pregnancy-associated plasma protein A (PAPPA) have been employed for screening, achieving a detection rate of approximately 90% for fetuses with Down syndrome, albeit with a false positive rate of 5%. While amniocentesis remains the gold standard for the prenatal diagnosis of chromosomal abnormalities, including Down syndrome and Edwards syndrome, its invasive nature carries a significant risk of complications, such as infection, preterm labor, or miscarriage, occurring at a rate of 7 per 1000 procedures.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China.
In this study, molecular dynamics (MD) simulations were employed to compare the effects of different solidification conditions on the solidification behaviour, stress distribution, and degree of crystallization of iron. The results indicate significant differences in nucleation and microstructural evolution between the two solidification methods. In the homogeneous temperature field, the solidification of iron is characterized by instantaneous nucleation.
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