8 research outputs found
Role of Lithium Ordering in the Li<sub><i>x</i></sub>TiO<sub>2</sub> Anatase → Titanate Phase Transition
The mechanism of the tetragonal ↔ orthorhombic phase separation of Li-intercalated anatase TiO<sub>2</sub> has previously been proposed to be a cooperative Jahn–Teller distortion due to occupation of low-lying Ti 3d<sub><i>xz</i>,<i>yz</i></sub> orbitals. Using density functional calculations, we show that the orthorhombic distortion of Li<sub>0.5</sub>TiO<sub>2</sub> is not a purely electronic phenomenon and that intercalated Li plays a critical role. For a 2 × 1 × 1 expanded supercell for 0 ≤ <i>x</i>(Li) ≤ 1, the intercalation voltage is minimized for <i>x</i>(Li) = 0.5. The low-energy structures display a common structural motif of edge-sharing pairs of LiO<sub>6</sub> octahedra, which allows all Li to adopt favorable oxygen coordination. Long-ranged disorder of these subunits explains the apparent random Li distribution seen in experimental diffraction data
Nature of the Superionic Phase Transition of Lithium Nitride from Machine Learning Force Fields
Superionic conductors have great potential as solid-state
electrolytes,
but the physics of type-II superionic transitions remains elusive.
In this study, we employed molecular dynamics simulations, using machine
learning force fields, to investigate the type-II superionic phase
transition in α-Li3N. We characterized Li3N above and below the superionic phase transition by calculating
the heat capacity, Li+ ion self-diffusion coefficient,
and Li defect concentrations as functions of temperature. Our findings
indicate that both the Li+ self-diffusion coefficient and
Li vacancy concentration follow distinct Arrhenius relationships in
the normal and superionic regimes. The activation energies for self-diffusion
and Li vacancy formation decrease by a similar proportion across the
superionic phase transition. This result suggests that the superionic
transition may be driven by a decrease in defect formation energetics
rather than changes in Li transport mechanism. This insight may have
implications for other type-II superionic materials
Sticky Architecture: Encoding Pressure Sensitive Adhesion in Polymer Networks
Pressure sensitive adhesives (PSAs) are ubiquitous materials
within
a spectrum that span from office supplies to biomedical devices. Currently,
the ability of PSAs to meet the needs of these diverse applications
relies on trial-and-error mixing of assorted chemicals and polymers,
which inherently entails property imprecision and variance over time
due to component migration and leaching. Herein, we develop a precise
additive-free PSA design platform that predictably leverages polymer
network architecture to empower comprehensive control over adhesive
performance. Utilizing the chemical universality of brush-like elastomers,
we encode work of adhesion ranging 5 orders of magnitude with a single
polymer chemistry by coordinating brush architectural parameters–side
chain length and grafting density. Lessons from this design-by-architecture
approach are essential for future implementation of AI machinery in
molecular engineering of both cured and thermoplastic PSAs incorporated
into everyday use
Sticky Architecture: Encoding Pressure Sensitive Adhesion in Polymer Networks
Pressure sensitive adhesives (PSAs) are ubiquitous materials
within
a spectrum that span from office supplies to biomedical devices. Currently,
the ability of PSAs to meet the needs of these diverse applications
relies on trial-and-error mixing of assorted chemicals and polymers,
which inherently entails property imprecision and variance over time
due to component migration and leaching. Herein, we develop a precise
additive-free PSA design platform that predictably leverages polymer
network architecture to empower comprehensive control over adhesive
performance. Utilizing the chemical universality of brush-like elastomers,
we encode work of adhesion ranging 5 orders of magnitude with a single
polymer chemistry by coordinating brush architectural parameters–side
chain length and grafting density. Lessons from this design-by-architecture
approach are essential for future implementation of AI machinery in
molecular engineering of both cured and thermoplastic PSAs incorporated
into everyday use
Sticky Architecture: Encoding Pressure Sensitive Adhesion in Polymer Networks
Pressure sensitive adhesives (PSAs) are ubiquitous materials
within
a spectrum that span from office supplies to biomedical devices. Currently,
the ability of PSAs to meet the needs of these diverse applications
relies on trial-and-error mixing of assorted chemicals and polymers,
which inherently entails property imprecision and variance over time
due to component migration and leaching. Herein, we develop a precise
additive-free PSA design platform that predictably leverages polymer
network architecture to empower comprehensive control over adhesive
performance. Utilizing the chemical universality of brush-like elastomers,
we encode work of adhesion ranging 5 orders of magnitude with a single
polymer chemistry by coordinating brush architectural parameters–side
chain length and grafting density. Lessons from this design-by-architecture
approach are essential for future implementation of AI machinery in
molecular engineering of both cured and thermoplastic PSAs incorporated
into everyday use
Sticky Architecture: Encoding Pressure Sensitive Adhesion in Polymer Networks
Pressure sensitive adhesives (PSAs) are ubiquitous materials
within
a spectrum that span from office supplies to biomedical devices. Currently,
the ability of PSAs to meet the needs of these diverse applications
relies on trial-and-error mixing of assorted chemicals and polymers,
which inherently entails property imprecision and variance over time
due to component migration and leaching. Herein, we develop a precise
additive-free PSA design platform that predictably leverages polymer
network architecture to empower comprehensive control over adhesive
performance. Utilizing the chemical universality of brush-like elastomers,
we encode work of adhesion ranging 5 orders of magnitude with a single
polymer chemistry by coordinating brush architectural parameters–side
chain length and grafting density. Lessons from this design-by-architecture
approach are essential for future implementation of AI machinery in
molecular engineering of both cured and thermoplastic PSAs incorporated
into everyday use
Sticky Architecture: Encoding Pressure Sensitive Adhesion in Polymer Networks
Pressure sensitive adhesives (PSAs) are ubiquitous materials
within
a spectrum that span from office supplies to biomedical devices. Currently,
the ability of PSAs to meet the needs of these diverse applications
relies on trial-and-error mixing of assorted chemicals and polymers,
which inherently entails property imprecision and variance over time
due to component migration and leaching. Herein, we develop a precise
additive-free PSA design platform that predictably leverages polymer
network architecture to empower comprehensive control over adhesive
performance. Utilizing the chemical universality of brush-like elastomers,
we encode work of adhesion ranging 5 orders of magnitude with a single
polymer chemistry by coordinating brush architectural parameters–side
chain length and grafting density. Lessons from this design-by-architecture
approach are essential for future implementation of AI machinery in
molecular engineering of both cured and thermoplastic PSAs incorporated
into everyday use
Sticky Architecture: Encoding Pressure Sensitive Adhesion in Polymer Networks
Pressure sensitive adhesives (PSAs) are ubiquitous materials
within
a spectrum that span from office supplies to biomedical devices. Currently,
the ability of PSAs to meet the needs of these diverse applications
relies on trial-and-error mixing of assorted chemicals and polymers,
which inherently entails property imprecision and variance over time
due to component migration and leaching. Herein, we develop a precise
additive-free PSA design platform that predictably leverages polymer
network architecture to empower comprehensive control over adhesive
performance. Utilizing the chemical universality of brush-like elastomers,
we encode work of adhesion ranging 5 orders of magnitude with a single
polymer chemistry by coordinating brush architectural parameters–side
chain length and grafting density. Lessons from this design-by-architecture
approach are essential for future implementation of AI machinery in
molecular engineering of both cured and thermoplastic PSAs incorporated
into everyday use