6 research outputs found
Dual-action self-healing protective coatings with photothermal responsive corrosion inhibitor nanocontainers
No full textThis work introduces a novel nanocomposite coating with dual-action self-healing corrosion protection activated by the photothermal response of plasmonic titanium nitride nanoparticles (TiN NPs). TiN@mesoporous SiO2 core–shell nanocontainers were developed as reservoirs for benzotriazole (BTA) corrosion inhibitors and incorporated into the shape memory epoxy coating matrix. Under near-infrared (NIR) light irradiation, the thermogenesis effect of TiN could not only promote the release of corrosion inhibitors from nanocontainers into the crevice, but also trigger the shape memory effect of damaged epoxy to merge the coating scratch. As such, the dual-action self-healing mechanisms combining the formation of an inhibitor-based protective layer and the scratch closure efficiently suppressed the corrosion process at the exposed metal surface. Surface characterization and electrochemical measurement results proved that the nanocomposite coating incorporated with 2 wt% of TiN-BTA@SiO2 exhibited the optimal corrosion protection as well as an excellent self-healing performance that can be initiated within 30 s of NIR illumination. This photo-controlled self-healing approach is potentially useful in designing next-generation self-healing coatings with ultrafast response time and high healing efficiency.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Arjan Mo
High-temperature ferromagnetism in two-dimensional material MnSn originated from interlayer coupling
No full textMnSn monolayer synthesized recently is a novel two-dimensional ferromagnetic
material with a hexagonal lattice, in which three Mn atom come together to form
a trimer, making it remarkably different from other magnetic two-dimensional
materials. Most impressively, there happens a sharp increase of Curie
temperature from 54 K to 225 K when the number of layers increase from 1 to 3.
However, no quantitative explanation is reported in previous studies. Herein,
by means of first-principle calculations method and Monte carlo method, we
demonstrate that strong interlayer ferromagnetic coupling is the essential role
in enhancing its critical temperature, which act as a magnetic field to
stabilize the ferromagnetism in the MnSn multilayers
Prediction of single-atom-thick transition metal nitride CrN with a square-planar network and high-temperature ferromagnetism
No full textSingle-atom-thick two-dimensional materials such as graphene usually have a
hexagonal lattice while the square-planar lattice is uncommon in the family of
two-dimensional materials. Here, we demonstrate that single-atom-thick
transition metal nitride CrN monolayer is a stable free-standing layer with
a square-planar network.
The stability of square-planar geometry is ascribed to the combination of N=N
double bond, Cr-N coordination bond, and -d conjugation, in which the
double -d conjugation is rarely reported in previous studies.
This mechanism is entirely different from that of the reported
two-dimensional materials, leading to lower formation energy and more robust
stability compared to the synthesized g-CN monolayer.
On the other hand, CrN layer has a ferromagnetic ground state, in which
the ferromagnetic coupling between two Cr atoms is mediated by electrons of the
half-filled large orbitals from -d conjugation.
The high-temperature ferromagnetism in CrN monolayer is confirmed by
solving the Heisenberg model with Monte Carlo method.Comment: https://link.aps.org/doi/10.1103/PhysRevB.106.12542
Achieving high-temperature ferromagnetism by means of magnetic ions dimerization
No full textMagnetic two-dimensional materials have potential application in
next-generation electronic devices and have stimulated extensive interest in
condensed matter physics and material fields. However, how to realize
high-temperature ferromagnetism in two-dimensional materials remains a great
challenge in physics.
Herein, we propose an effective approach that the dimerization of magnetic
ions in two-dimensional materials can enhance the exchange coupling and
stabilize the ferromagnetism.
Manganese carbonitride MnNC with a planar monolayer structure is
taken as an example to clarify the method, in which two Mn atoms are gathered
together to form a ferromagnetic dimer of Mn atoms and further these dimers are
coupled together to form the overall ferromagnetism of the two-dimensional
material.
In MnNC monolayer, the near-room-temperature ferromagnetism with
the Curie temperature of 272.3 K is determined by solving Heisenberg model
using Monte Carlo simulations method.Comment: Journal of Physical Chemistry C Cite This:
https://doi.org/10.1021/acs.jpcc.2c0259
Positive Rates and Factors Associated with Abnormal Lung Function of Greenhouse Workers in China: A Cross-Sectional Study
No full textSince the number of greenhouse workers are increasing in China, this observational cross-sectional study was designed to evaluate lung function and discuss the potential risk factors, to provide evidence in the surveillance of greenhouse workers' health. 678 greenhouse workers in Gansu Province, China were enrolled. A questionnaire which included demographic and occupational information was used. Vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and FEV1: FVC ratios (FEV1/FVC), maximal expiratory flow after 50% of the FVC has not been exhaled (MEF50), maximal expiratory flow after 25% of the FVC has not been exhaled (MEF25) and maximal mid-expiratory flow curve (MMEF) were measured as lung function indicators. The mean values and standard deviations (SDs) of VC% predicted, FVC% predicted, FEV1% predicted and FEV1/FVC ratio were 106.07 +/- 13.36, 107.60 +/- 13.95, 97.19 +/- 14.80 and 89.76 +/- 10.78 respectively. The positive rates of above four and abnormal lung ventilation function were 2.9%, 2.8%, 11.2%, 4.6% and 6.5% respectively. Gender, age, BMI and number of greenhouses owned were influence factors of lung ventilation function (p < 0.05). The mean values and SDs of MEF50% predicted, MEF25% predicted and MMEF% predicted were 69.63 +/- 24.95, 54.04 +/- 24.94 and 66.81 +/- 24.53. The positive rates of above three and abnormal small airway function were 45.0%, 72.1%, 47.2% and 49.4% respectively. Age, education and number of greenhouses owned were influence factors for small airway function (p < 0.05). Working in a greenhouse might influence lung function of the workers. Small airway function indicators could be used as priority indicators for the surveillance of greenhouse workers' health.SCI(E)SSCIARTICLE91
Two-dimensional binary transition metal nitride N ( = V, Cr, Mn, Fe, Co) with a graphene-like structure and strong magnetic properties
No full textBinary transition metal nitride with a graphene-like structure and strong
magnetic properties is rare. Based on the first-principles calculations, we
design two kinds of N ( =transition metal) monolayers, which are
transition metal nitrides with a planar structure, made up of N units
aligned in the rhombic and square patterns. The two structural lattices have
robust stability and good compatibility with different metal atoms, and the
underlying mechanism is the combination of hybridization, coordinate
bond, and conjugation. With the metal atom changing from V, Cr, Mn, Fe to
Co, the total charge of N system increases by one electron in turn,
which results in continuous adjustability of the electronic and magnetic
properties. The planar ligand field is another feature of the two N
lattices, which brings about the special splitting of five suborbitals of 3
metal atom and gives rise to strong magnetism. Moreover, room-temperature
ferromagnetism in square-CoN monolayer with the Curie temperatures of 321 K
is determined by solving the Heisenberg model combined with Monte Carlo method
