̽��ֱ�� of Cambridge - Angelos Michaelides

New form of ice is like a snapshot of liquid water

cr696 — Thu, 02 Feb 2023 19:00:00 +0000

̽��ֱ��new form of ice is amorphous. Unlike ordinary crystalline ice where the molecules arrange themselves in a regular pattern, in amorphous ice the molecules are in a disorganised form that resembles a liquid.

In their paper, published in Science, the team created a new form of amorphous ice in experiment and achieved an atomic-scale model of it in computer simulation. ̽��ֱ��experiments used a technique called ball-milling, which grinds crystalline ice into small particles using metal balls in a steel jar. Ball-milling is regularly used to make amorphous materials, but it had never been applied to ice.

̽��ֱ��team found that ball-milling created an amorphous form of ice, which unlike all other known ices, had a density similar to that of liquid water and whose state resembled water in solid form. They named the new ice medium-density amorphous ice (MDA).

To understand the process at the molecular scale the team employed computational simulation. By mimicking the ball-milling procedure via repeated random shearing of crystalline ice, the team successfully created a computational model of MDA.

“Our discovery of MDA raises many questions on the very nature of liquid water and so understanding MDA’s precise atomic structure is very important,” said co-author Dr Michael Davies, who carried out the computational modelling. “We found remarkable similarities between MDA and liquid water.”

A happy medium

Amorphous ices have been suggested to be models for liquid water. Until now, there have been two main types of amorphous ice: high-density and low-density amorphous ice.

As the names suggest, there is a large density gap between them. This density gap, combined with the fact that the density of liquid water lies in the middle, has been a cornerstone of our understanding of liquid water. It has led in part to the suggestion that water consists of two liquids: one high- and one low-density liquid.

Senior author Professor Christoph Salzmann said: “ ̽��ֱ��accepted wisdom has been that no ice exists within that density gap. Our study shows that the density of MDA is precisely within this density gap and this finding may have far-reaching consequences for our understanding of liquid water and its many anomalies.”

A high-energy geophysical material

̽��ֱ��discovery of MDA gives rise to the question: where might it exist in nature? Shear forces were discovered to be key to creating MDA in this study. ̽��ֱ��team suggests ordinary ice could undergo similar shear forces in the ice moons due to the tidal forces exerted by gas giants such as Jupiter.

Moreover, MDA displays one remarkable property that is not found in other forms of ice. Using calorimetry, they found that when MDA recrystallises to ordinary ice it releases an extraordinary amount of heat. ̽��ֱ��heat released from the recrystallization of MDA could play a role in activating tectonic motions. More broadly, this discovery shows water can be a high-energy geophysical material.

Professor Angelos Michaelides, lead author from Cambridge's Yusuf Hamied Department of Chemistry, said: “Amorphous ice in general is said to be the most abundant form of water in the universe. ̽��ֱ��race is now on to understand how much of it is MDA and how geophysically active MDA is.”

Reference:
Alexander Rosu-Finsen et al. 'Medium-density amorphous ice.' Science (2023). DOI: 10.1126/science.abq2105

A collaboration between scientists at Cambridge and UCL has led to the discovery of a new form of ice that more closely resembles liquid water than any other and may hold the key to understanding this most famous of liquids.

Our discovery of MDA raises many questions on the very nature of liquid water and so understanding MDA’s precise atomic structure is very important

Michael Davies

Christoph Salzmann

Part of the set-up for creating medium-density amorphous ice: ordinary ice and steel balls in a jar (not amorphous ice)

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

New phases of water detected

sc604 — Wed, 14 Sep 2022 15:27:56 +0000

Scientists at the ̽��ֱ�� of Cambridge have discovered that water in a one-molecule layer acts like neither a liquid nor a solid, and that it becomes highly conductive at high pressures.

Much is known about how ‘bulk water’ behaves: it expands when it freezes, and it has a high boiling point. But when water is compressed to the nanoscale, its properties change dramatically.

By developing a new way to predict this unusual behaviour with unprecedented accuracy, the researchers have detected several new phases of water at the molecular level.

Water trapped between membranes or in tiny nanoscale cavities is common – it can be found in everything from membranes in our bodies to geological formations. But this nanoconfined water behaves very differently from the water we drink.

Until now, the challenges of experimentally characterising the phases of water on the nanoscale have prevented a full understanding of its behaviour. But in a paper published in the journal Nature, the Cambridge-led team describe how they have used advances in computational approaches to predict the phase diagram of a one-molecule thick layer of water with unprecedented accuracy.

They used a combination of computational approaches to enable the first-principles level investigation of a single layer of water.

̽��ֱ��researchers found that water which is confined into a one-molecule thick layer goes through several phases, including a ‘hexatic’ phase and a ‘superionic’ phase. In the hexatic phase, the water acts as neither a solid nor a liquid, but something in between. In the superionic phase, which occurs at higher pressures, the water becomes highly conductive, propelling protons quickly through ice in a way resembling the flow of electrons in a conductor.

Understanding the behaviour of water at the nanoscale is critical to many new technologies. ̽��ֱ��success of medical treatments can be reliant on how water trapped in small cavities in our bodies will react. ̽��ֱ��development of highly conductive electrolytes for batteries, water desalination, and the frictionless transport of fluids are all reliant on predicting how confined water will behave.

“For all of these areas, understanding the behaviour of water is the foundational question,” said Dr Venkat Kapil from Cambridge’s Yusuf Hamied Department of Chemistry, the paper’s first author. “Our approach allows the study of a single layer of water in a graphene-like channel with unprecedented predictive accuracy.”

̽��ֱ��researchers found that the one-molecule thick layer of water within the nanochannel showed rich and diverse phase behaviour. Their approach predicts several phases which include the hexatic phase--an intermediate between a solid and a liquid--and also a superionic phase, in which the water has a high electrical conductivity.

“ ̽��ֱ��hexatic phase is neither a solid nor a liquid, but an intermediate, which agrees with previous theories about two-dimensional materials,” said Kapil. “Our approach also suggests that this phase can be seen experimentally by confining water in a graphene channel.

“ ̽��ֱ��existence of the superionic phase at easily accessible conditions is peculiar, as this phase is generally found in extreme conditions like the core of Uranus and Neptune. One way to visualise this phase is that the oxygen atoms form a solid lattice, and protons flow like a liquid through the lattice, like kids running through a maze.”

̽��ֱ��researchers say this superionic phase could be important for future electrolyte and battery materials as it shows an electrical conductivity 100 to 1,000 times higher than current battery materials.

̽��ֱ��results will not only help with understanding how water works at the nanoscale, but also suggest that ‘nanoconfinement’ could be a new route into finding superionic behaviour of other materials.

Dr Venkat Kapil is a Junior Research Fellow at Churchill College, Cambridge. ̽��ֱ��research team included Dr Christoph Schran and Professor Angelos Michaelides from the Yusuf Hamied Department of Chemistry ICE group, working with Professor Chris Pickard at the Department of Materials Science & Metallurgy, Dr Andrea Zen from the ̽��ֱ�� of Naples Federico II and Dr Ji Chen from Peking ̽��ֱ��.

Reference:
Angelos Michaelides et al. ‘ ̽��ֱ��first-principles phase diagram of monolayer nanoconfined water.’ Nature (2022). DOI: 10.1038/s41586-022-05036-x

Water can be liquid, gas or ice, right? Think again.

One way to visualise this phase is that the oxygen atoms form a solid lattice, and protons flow like a liquid through the lattice, like kids running through a maze

Venkat Kapil

Daniel Sonoca via Unsplash

Water

Yes

Nine Cambridge scientists among the new 2022 Fellows announced by the Royal Society

jg533 — Tue, 10 May 2022 11:33:12 +0000

̽��ֱ��Royal Society is a self-governing Fellowship made up of the most eminent scientists, engineers and technologists from the UK and the Commonwealth. Its Foreign Members are drawn from the rest of the world.

̽��ֱ��Society’s fundamental purpose is to recognise, promote, and support excellence in science and to encourage the development and use of science for the benefit of humanity.

This year, a total of 51 Fellows, 10 Foreign Members, and one Honorary Fellow have been selected for their outstanding contributions to science.

Sir Adrian Smith, President of the Royal Society said: “It is an honour to welcome so many outstanding researchers from around the world into the Fellowship of the Royal Society.

“Through their careers so far, these researchers have helped further our understanding of human disease, biodiversity loss and the origins of the universe. I am also pleased to see so many new Fellows working in areas likely to have a transformative impact on our society over this century, from new materials and energy technologies to synthetic biology and artificial intelligence. I look forward to seeing what great things they will achieve in the years ahead.”

̽��ֱ��Cambridge Fellows are:

Professor Graham Burton FMedSci FRS

Mary Marshall and Arthur Walton Professor Emeritus of the Physiology of Reproduction, ̽��ֱ�� of Cambridge

Burton is a reproductive biologist whose research has focused on the early stages of human pregnancy. In particular, he showed how the placenta is established in a protective low-oxygen environment, stimulating its own development through interactions with the uterus. He demonstrated that aberrations in the early stages of placental development can adversely affect the life-long health of mother and offspring. Burton was founding Director of the Centre for Trophoblast Research, and founding Chair of the Strategic Research Initiative Cambridge Reproduction.

He said: “I am delighted to receive this recognition for myself and the field of reproductive biology, and thank colleagues and collaborators for their contributions over the years.”

Professor Roberto Cipolla FREng FRS

Professor of Information Engineering, Department of Engineering, ̽��ֱ�� of Cambridge

Cipolla is distinguished for his research in computer vision and his contributions to the reconstruction, registration and recognition of three-dimensional objects from images. These include novel algorithms for the recovery of accurate 3D shape, visual localisation and semantic segmentation and their translation into commercial products.

He said: "This is the ultimate honour for any scientist and recognises the amazing contribution of my students, collaborators and mentors in my 30 years at Cambridge. I am also very fortunate to be working in the field of computer vision and machine learning at a time of revolutionary progress and ground-breaking applications.”

Professor Douglas Easton FMedSci FRS

Professor of Genetic Epidemiology, Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary Care, ̽��ֱ�� of Cambridge

Easton’s main research interests are in cancer genetics. He analyses large population studies to identify genetic variants that predispose to cancer, and to understand how they combine together with other factors to determine cancer risk. His work has characterised many important cancer genes such as BRCA1 and BRCA2, and identified of hundreds of common cancer predisposition variants in the non-coding genome. He co-developed the BOADICEA risk prediction model now used worldwide to guide genetic counselling and cancer prevention.

He said: "I am truly delighted and honoured to be elected to the Fellowship of the Royal Society. This prestigious honour is a tribute the work of many wonderful colleagues in Cambridge and worldwide, over many years, who have made the research possible."

Professor Robin Franklin FMedSci FRS

Formerly Professor of Stem Cell Medicine, Wellcome - MRC Cambridge Stem Cell Institute, ̽��ֱ�� of Cambridge; now Principal Investigator, Altos Labs - Cambridge Institute

̽��ֱ��central question of Franklin’s career is 'how do tissues regenerate?' To address this question, he has studied the brain, an organ notorious for its poor regenerative capacity. Working with many excellent colleagues, he has described how stem cells in the adult brain regenerate oligodendrocytes - the cells responsible for making the insulating myelin sheath around nerve fibres - once they are lost in diseases such as multiple sclerosis (MS); how this process declines with age; and it can be reversed. ̽��ֱ��work has led to two regenerative medicine trials in MS.

He said: “I am absolutely delighted to have been elected a Fellow of the Royal Society - it is a huge honour.”

Professor Richard Gilbertson FMedSci FRS

Li Ka Shing Chair of Oncology and Head of Department of Oncology, ̽��ֱ�� of Cambridge, Director of Cancer Research UK Cambridge Centre and Senior Group Leader, Cancer Research UK Cambridge Institute

Gilbertson, a paediatric physician-scientist, has identified the origins of common and aggressive childhood brain tumours and many of the genetic alterations that drive these tumours. His research has helped establish a direct link between disordered development and the multiple different brain tumour types observed in children: contributing directly to their classification by the World Health Organisation (WHO); changing the way conventional treatments are used, sparing children from unnecessary side effects; and underpinning clinical trials of new therapies.

Gilbertson said: “I am truly delighted and humbled to receive this recognition that I share with all the wonderful students, trainees and colleagues I have worked with over the years.”

Professor Paul Lehner FMedSci FRS

Professor of Immunology and Medicine, Cambridge Institute for Medical Research, ̽��ֱ�� of Cambridge

Lehner studies virus-host antagonism and how our genome is defended from invasion by RNA-derived retroelements such as HIV. His discovery of the ‘HUSH’ epigenetic silencing complex explains how the genome distinguishes new genetic material from endogenous genes through recognition of intronless DNA. This work uncovered an unanticipated surveillance system that discriminates ‘self’ from ‘non-self’ genomic DNA and defends our genome against the reverse flow of genetic information (RNA to DNA), paving the way to novel applications in medicine and biotechnology.

Lehner said: “I’m absolutely delighted to be elected to the Fellowship of the Royal Society; I’ve been fortunate to work with incredibly talented people and this honour recognises the commitment of the many past and present members of my group who have contributed to our work.”

Professor Roberto Maiolino FRS

Director of the Kavli Institute for Cosmology and Professor of Experimental Astrophysics, ̽��ֱ�� of Cambridge

Maiolino studies the formation of galaxies using observations collected at some of the largest ground-based and space telescopes. He has obtained key results on the interplay between the evolution of galaxies and the supermassive black holes at their centres. He has also investigated the enrichment of chemical elements across the cosmic epochs, as well as the origin and nature of dust particles in the early Universe.

He said: “I am truly honoured by such a prestigious appointment. Being a Fellow of the Royal Society will certainly foster my research activities and will allow me to further promote exciting, cutting-edge projects.”

Professor Angelos Michaelides FRS

1968 Professor of Chemistry, Yusuf Hamied Department of Chemistry, ̽��ֱ�� of Cambridge

Michaelides’ work involves the development and application of theoretical methods to better understand contemporary problems in chemistry, physics, and materials science. His group places a particular focus on developing and applying computer simulation approaches that provide the fundamental molecular-level insight needed to help address contemporary global challenges related to water, energy, and the environment.

He said: “Holy moly! I’m delighted to have been elected an FRS and very grateful to all the outstanding students, post-docs, collaborators, and mentors I’ve had over the years without whom this would never have happened.”

Professor Jason William Chin FMedSci FRS

Head, Centre for Chemical and Synthetic Biology, and Joint Head, Division of Protein and Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology; Professor of Chemistry and Chemical Biology, Yusuf Hamied Department of Chemistry, ̽��ֱ�� of Cambridge; Associate Faculty in Synthetic Genomics, Wellcome Sanger Institute

Chin has engineered the genetic code of living cells to synthesise modified proteins and non-canonical polymers. To accomplish this, he created new translational machinery and codons to reprogram the genetic code, going well-beyond prior work using amber suppression. He then completely synthesised a bacterial genome in which he reduced the number of sense codons in its genetic code. ̽��ֱ��codons thus unused were reassigned to encode non-canonical amino acids. Chin's fundamental advances have been widely used to drive discovery, including to define the molecular consequences of post-translational modifications, define protein interactions in cells, and provide mechanistic insight into enzymes.

̽��ֱ��nine Cambridge researchers were all selected for their exceptional contributions to science.

It is an honour to welcome so many outstanding researchers from around the world into the Fellowship of the Royal Society.

Sir Adrian Smith, President of the Royal Society

Yes