Electronics & Semiconductors
In the future, smart clothing might monitor our posture, communicate with smartphones and manage our body temperature. But first, scientists need to find a way to cost-effectively print intricate, flexible and durable circuits ...
Apr 13, 2022
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148
Energy & Green Tech
Researchers at Lund University in Sweden are investigating a car fuel comprised of a liquid that is converted to hydrogen by a solid catalyst. The used liquid is then emptied from the tank and charged with hydrogen, after ...
Oct 12, 2023
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76
Energy & Green Tech
Minerals as well as freshwater can be obtained by desalinating seawater with solar power facilities for the sustainable development of human civilization. For instance, hydrogels have shown great power for solar-powered water ...
Energy & Green Tech
One of nature's most common organic materials—lignin—can be used to create stable and environmentally friendly organic solar cells. Researchers at Linköping University and the Royal Institute of Technology (KTH) have ...
Dec 6, 2023
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151
Robotics
Cornell University engineers have created a soft robot capable of detecting when and where it was damaged—and then healing itself on the spot.
Dec 7, 2022
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147
Energy & Green Tech
A Chinese research team has developed a new concept for extracting thermal energy from low-temperature waste heat sources and reusing it on demand simply by controlling the pressure.
Feb 17, 2023
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254
Robotics
Scientists at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia have developed a tiny "claw machine" that is able to pick up and drop a marble-sized ball in response to exposure to chemical vapors.
Jul 12, 2024
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38
A hydrogen bond is the attractive interaction of a hydrogen atom with an electronegative atom, like nitrogen, oxygen or fluorine (thus the name "hydrogen bond", which must not be confused with a covalent bond to hydrogen). The hydrogen is covalently bonded to another electronegative atom. The energy of a hydrogen bond (typically 5 to 30 kJ/mole) is comparable to that of weak covalent bonds (155 kJ/mol), and a typical covalent bond is only 20 times stronger than an intermolecular hydrogen bond. These bonds can occur between molecules (intermolecularly), or within different parts of a single molecule (intramolecularly). The hydrogen bond is stronger than a van der Waals interaction, but weaker than covalent, or ionic bonds. This type of bond occurs in both inorganic molecules such as water and organic molecules such as DNA.
Intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C). This is because of the strong hydrogen bond, as opposed to other group 16 hydrides. Intramolecular hydrogen bonding is partly responsible for the secondary, tertiary, and quaternary structures of proteins and nucleic acids.
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