7 research outputs found
Exploring the Role of Adsorption and Surface State on the Hydrophobicity of Rare Earth Oxides
Rare
earth oxides (REOs) are attracting attention for use as cost-effective,
high-performance dropwise condensers because of their favorable thermal
properties and robust nature. However, to engineer a suitable surface
for industrial applications, the mechanism governing wetting must
be first fully elucidated. Recent studies exploring the water-wetting
state of REOs have suggested that these oxides are intrinsically hydrophobic
owing to the unique electronic structure of the lanthanide series.
These claims have been countered with evidence that they are inherently
hydrophilic and that adsorption of contaminants from the environment
is responsible for the <i>apparent</i> hydrophobic nature
of these surfaces. Here, using X-ray photoelectron spectroscopy and
dynamic water contact angle measurements, we provide further evidence
to show that REOs are intrinsically hydrophilic, with ceria demonstrating
advancing water contact angles of ā6Ā° in a clean surface
state and similar surface energies to two transition metal oxides
(ā³72 mJ/m<sup>2</sup>). Using two model volatile species, it
is shown that an adsorption mechanism is responsible for the apparent
hydrophobic property observed in REOs as well as in transition metal
oxides and silica. This is correlated with the screening of the polar
surface energy contribution of the underlying oxide with apparent
surface energies reduced to <40 mJ/m<sup>2</sup> for the case of
nonane adsorption. Moreover, we show that the degree of surface hydroxylation
plays an important role in the observed contact angle hysteresis with
the receding contact angle of ceria increasing from ā¼10Ā°
to 45Ā° following thermal annealing in an inert atmosphere. Our
findings suggest that high atomic number metal oxides capable of strongly
adsorbing volatile species may represent a viable paradigm toward
realizing robust surface coating for industrial condensers if certain
challenges can be overcome
Taming Electrowetting Using Highly Concentrated Aqueous Solutions
Wetting of carbon surfaces is one of the most widespread,
yet poorly
understood, physical phenomena. Control over wetting properties underpins
the operation of aqueous energy-storage devices and carbon-based filtration
systems. Electrowetting, the variation in the contact angle with an
applied potential, is the most straightforward way of introducing
control over wetting. Here, we study electrowetting directly on graphitic
surfaces with the use of aqueous electrolytes to show that reversible
control of wetting can be achieved and quantitatively understood using
models of the interfacial capacitance. We manifest that the use of
highly concentrated aqueous electrolytes induces a fully symmetric
and reversible wetting behavior without degradation of the substrate
within the unprecedented potential window of 2.8 V. We demonstrate
where the classical āYoungāLippmannā models apply,
and break down, and discuss reasons for the latter, establishing relations
among the applied bias, the electrolyte concentration, and the resultant
contact angle. The approach is extended to electrowetting at the liquid|liquid
interface, where a concentrated aqueous electrolyte drives reversibly
the electrowetting response of an insulating organic phase with a
significantly decreased potential threshold. In summary, this study
highlights the beneficial effect of highly concentrated aqueous electrolytes
on the electrowettability of carbon surfaces, being directly related
to the performance of carbon-based aqueous energy-storage systems
and electronic and microfluidic devices
Taming Electrowetting Using Highly Concentrated Aqueous Solutions
Wetting of carbon surfaces is one of the most widespread,
yet poorly
understood, physical phenomena. Control over wetting properties underpins
the operation of aqueous energy-storage devices and carbon-based filtration
systems. Electrowetting, the variation in the contact angle with an
applied potential, is the most straightforward way of introducing
control over wetting. Here, we study electrowetting directly on graphitic
surfaces with the use of aqueous electrolytes to show that reversible
control of wetting can be achieved and quantitatively understood using
models of the interfacial capacitance. We manifest that the use of
highly concentrated aqueous electrolytes induces a fully symmetric
and reversible wetting behavior without degradation of the substrate
within the unprecedented potential window of 2.8 V. We demonstrate
where the classical āYoungāLippmannā models apply,
and break down, and discuss reasons for the latter, establishing relations
among the applied bias, the electrolyte concentration, and the resultant
contact angle. The approach is extended to electrowetting at the liquid|liquid
interface, where a concentrated aqueous electrolyte drives reversibly
the electrowetting response of an insulating organic phase with a
significantly decreased potential threshold. In summary, this study
highlights the beneficial effect of highly concentrated aqueous electrolytes
on the electrowettability of carbon surfaces, being directly related
to the performance of carbon-based aqueous energy-storage systems
and electronic and microfluidic devices
Taming Electrowetting Using Highly Concentrated Aqueous Solutions
Wetting of carbon surfaces is one of the most widespread,
yet poorly
understood, physical phenomena. Control over wetting properties underpins
the operation of aqueous energy-storage devices and carbon-based filtration
systems. Electrowetting, the variation in the contact angle with an
applied potential, is the most straightforward way of introducing
control over wetting. Here, we study electrowetting directly on graphitic
surfaces with the use of aqueous electrolytes to show that reversible
control of wetting can be achieved and quantitatively understood using
models of the interfacial capacitance. We manifest that the use of
highly concentrated aqueous electrolytes induces a fully symmetric
and reversible wetting behavior without degradation of the substrate
within the unprecedented potential window of 2.8 V. We demonstrate
where the classical āYoungāLippmannā models apply,
and break down, and discuss reasons for the latter, establishing relations
among the applied bias, the electrolyte concentration, and the resultant
contact angle. The approach is extended to electrowetting at the liquid|liquid
interface, where a concentrated aqueous electrolyte drives reversibly
the electrowetting response of an insulating organic phase with a
significantly decreased potential threshold. In summary, this study
highlights the beneficial effect of highly concentrated aqueous electrolytes
on the electrowettability of carbon surfaces, being directly related
to the performance of carbon-based aqueous energy-storage systems
and electronic and microfluidic devices
Effects of rare kidney diseases on kidney failure: a longitudinal analysis of the UK National Registry of Rare Kidney Diseases (RaDaR) cohort
Individuals with rare kidney diseases account for 5-10% of people with chronic kidney disease, but constitute more than 25% of patients receiving kidney replacement therapy. The National Registry of Rare Kidney Diseases (RaDaR) gathers longitudinal data from patients with these conditions, which we used to study disease progression and outcomes of death and kidney failure.People aged 0-96 years living with 28 types of rare kidney diseases were recruited from 108 UK renal care facilities. The primary outcomes were cumulative incidence of mortality and kidney failure in individuals with rare kidney diseases, which were calculated and compared with that of unselected patients with chronic kidney disease. Cumulative incidence and Kaplan-Meier survival estimates were calculated for the following outcomes: median age at kidney failure; median age at death; time from start of dialysis to death; and time from diagnosis to estimated glomerular filtration rate (eGFR) thresholds, allowing calculation of time from last eGFR of 75 mL/min per 1Ā·73 m2 or more to first eGFR of less than 30 mL/min per 1Ā·73 m2 (the therapeutic trial window).Between Jan 18, 2010, and July 25, 2022, 27ā285 participants were recruited to RaDaR. Median follow-up time from diagnosis was 9Ā·6 years (IQR 5Ā·9-16Ā·7). RaDaR participants had significantly higher 5-year cumulative incidence of kidney failure than 2Ā·81 million UK patients with all-cause chronic kidney disease (28% vs 1%; p
Background
Methods
Findings
Interpretation
Funding</p