Mechanochemistry

Last updated

Mechanochemistry (or mechanical chemistry) is the initiation of chemical reactions by mechanical phenomena. Mechanochemistry thus represents a fourth way to cause chemical reactions, complementing thermal reactions in fluids, photochemistry, and electrochemistry. Conventionally mechanochemistry focuses on the transformations of covalent bonds by mechanical force. Not covered by the topic are many phenomena: phase transitions, dynamics of biomolecules (docking, folding), and sonochemistry. [1]

Contents

Mechanochemistry is not the same as mechanosynthesis, which refers specifically to the machine-controlled construction of complex molecular products. [2] [3]

In natural environments, mechanochemical reactions are frequently induced by physical processes such as earthquakes, [4] glacier movement [5] or hydraulic action of rivers or waves. In extreme environments such as subglacial lakes, hydrogen generated by mechnochemical reactions involving crushed silicate rocks and water can support methanogenic microbial communities. And mechanochemistry may have generated oxygen in the ancient Earth by water splitting on fractured mineral surfaces at high temperatures, potentially influencing life's origin or early evolution. [6]

History

The primal mechanochemical project was to make fire by rubbing pieces of wood against each other, creating friction and hence heat, triggering combustion at the elevated temperature. Another method involves the use of flint and steel, during which a spark (a small particle of pyrophoric metal) spontaneously combusts in air, starting fire instantaneously.

Industrial mechanochemistry began with the grinding of two solid reactants. Mercuric sulfide (the mineral cinnabar) and copper metal thereby react to produce mercury and copper sulfide: [7]

HgS + 2Cu → Hg + Cu2S

A special issue of Chemical Society Review was dedicated to mechanochemistry. [8]

Scientists recognized that mechanochemical reactions occur in environments naturally due to various processes, and the reaction products have the potential to influence microbial communities in tectonically active regions. [4] The field has garnered increasing attention recently as mechanochemistry has the potential to generate diverse molecules capable of supporting extremophilic microbes, [5] influencing the early evolution of life, [6] developing the systems necessary for the origin of life, [6] or supporting alien life forms. [9] The field has now inspired the initiation of a special research topic in the journal Frontiers in Geochemistry. [10]

Mechanical Processes

Natural

Earthquakes crush rocks across Earth's subsurface and on other tectonically active planets. Rivers also frequently abrade rocks, revealing fresh mineral surfaces and waves at a shore erode cliffs fracture rocks and abrade sediments. [11]

Similarly to rivers and oceans, the mechanical power of glaciers is evidenced by their impact on landscapes. As glaciers move downslope, they abrade rocks, generating fractured mineral surfaces that can partake in mechanochemical reactions.

Unnatural

In laboratories, planetary ball mills are typically used to induce crushing [5] [6] to investigate natural processes.

Mechanochemical transformations are often complex and different from thermal or photochemical mechanisms. [12] [13] Ball milling and ResonantAcoustic Mixing (RAM) are widely used processes in which mechanical force is used to achieve chemical transformations. [14] [15] [16]

It eliminates the need for many solvents, offering the possibility that mechanochemistry could help make many industries more environmentally friendly. [17] [18] For example, the mechanochemical process has been used to synthesize pharmaceutically-attractive phenol hydrazones. [19]

Chemical Reactions

Mechanochemical reactions encompass reactions between mechanically fractured solid materials and any other reactants present in the environment. However, natural mechanochemical reactions frequently involve the reaction of water with crushed rock, so called water-rock reactions. [6] [5] [4] Mechanochemistry is typically initiated by the breakage of bonds between atoms within many different mineral types.

Silicates

Silicates are the most common minerals in the Earth's crust, and thus comprise the mineral type most commonly involved in natural mechanochemical reactions. Silicates are made up of silicon and oxygen atoms, typically arranged in silicon tetrahedra. Mechanical processes break the bonds between the silicon and oxygen atoms. If the bonds are broken by a homolytic cleavage, unpaired electrons are generated:

≡Si–O–Si≡ → ≡Si–O• + ≡Si•

≡Si–O–O–Si≡ → ≡Si–O• + ≡Si–O•

≡Si–O–O–Si≡ → ≡Si–O–O• + ≡Si•

Hydrogen Generation

The reaction of water with silicon radicals can generate hydrogen radicals: [5]

2≡Si• + 2H2O → 2≡Si–O–H + 2H•

2H• → H2

This mechanism can generate H2 to support methanogens in environments with few other energy sources. However, at higher temperatures (~>80 °C [6] ), hydrogen radicals react with siloxyl radicals, preventing the generation of H2 by this mechanism: [4]

≡Si–O• + H• → ≡Si–O–H

2H• → H2

Oxidant Generation

When oxygen reacts with silicon or oxygen radicals at the surface of crushed rocks, it can chemically adsorb to the surface:

≡Si• + O2 → ≡Si–O–O•

≡Si–O• + O2 → ≡Si–O–O–O•

These oxygen radicals can then generate oxidants such as hydroxyl radicals and hydrogen peroxide: [20]

≡Si–O–O• + H2O → ≡Si–O–O–H + •OH

2•OH → H2O2

Additionally, oxidants may be generated in the absence of oxygen at high temperatures: [6]

≡Si–O• + H2O → ≡Si–O–H + •OH

2•OH → H2O2

H2O2 breaks down naturally in environments to form water and Oxygen gas:

2H2O2 → 2H2O + O2

Industry applications

Fundamentals and applications ranging from nano materials to technology have been reviewed. [21] The approach has been used to synthesize metallic nanoparticles, catalysts, magnets, γ‐graphyne, metal iodates, nickel–vanadium carbide and molybdenum–vanadium carbide nanocomposite powders. [22]

Ball milling has been used to separate hydrocarbon gases from crude oil. The process used 1-10% of the energy of conventional cryogenics. Differential absorption is affected by milling intensity, pressure and duration. The gases are recovered by heating, at a specific temperature for each gas type. The process has successfully processed alkyne, olefin and paraffin gases using boron nitride powder.

(Poly)lactic acid, a green material, can be upcycled into alkyl lactate esters by mechanochemistry, using alcohol as a reaction partner under resonant acoustic mixing. [23]

Storage

Mechanochemistry has potential for energy-efficient solid-state storage of hydrogen, ammonia and other fuel gases. The resulting powder is safer than conventional methods of compression and liquefaction. [24]

See also

Further reading

Related Research Articles

<span class="mw-page-title-main">Kaolinite</span> Phyllosilicate clay mineral

Kaolinite ( KAY-ə-lə-nyte, -⁠lih-; also called kaolin) is a clay mineral, with the chemical composition Al2Si2O5(OH)4. It is a layered silicate mineral, with one tetrahedral sheet of silica (SiO4) linked through oxygen atoms to one octahedral sheet of alumina (AlO6).

<span class="mw-page-title-main">Silicon</span> Chemical element with atomic number 14 (Si)

Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium are below it. It is relatively unreactive. Silicon is a significant element that is essential for several physiological and metabolic processes in plants. Silicon is widely regarded as the predominant semiconductor material due to its versatile applications in various electrical devices such as transistors, solar cells, integrated circuits, and others. These may be due to its significant band gap, expansive optical transmission range, extensive absorption spectrum, surface roughening, and effective anti-reflection coating.

<span class="mw-page-title-main">Silicate</span> Any polyatomic anion containing silicon and oxygen

A silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula [SiO(4-2x)−
4−x]
n, where 0 ≤ x < 2. The family includes orthosilicate SiO4−4, metasilicate SiO2−3, and pyrosilicate Si2O6−7. The name is also used for any salt of such anions, such as sodium metasilicate; or any ester containing the corresponding chemical group, such as tetramethyl orthosilicate. The name "silicate" is sometimes extended to any anions containing silicon, even if they do not fit the general formula or contain other atoms besides oxygen; such as hexafluorosilicate [SiF6]2−. Most commonly, silicates are encountered as silicate minerals.

<span class="mw-page-title-main">Silicon dioxide</span> Oxide of silicon

Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula SiO2, commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant families of materials, existing as a compound of several minerals and as a synthetic product. Examples include fused quartz, fumed silica, opal, and aerogels. It is used in structural materials, microelectronics, and as components in the food and pharmaceutical industries. All forms are white or colorless, although impure samples can be colored.

<span class="mw-page-title-main">Epitaxy</span> Crystal growth process relative to the substrate

Epitaxy refers to a type of crystal growth or material deposition in which new crystalline layers are formed with one or more well-defined orientations with respect to the crystalline seed layer. The deposited crystalline film is called an epitaxial film or epitaxial layer. The relative orientation(s) of the epitaxial layer to the seed layer is defined in terms of the orientation of the crystal lattice of each material. For most epitaxial growths, the new layer is usually crystalline and each crystallographic domain of the overlayer must have a well-defined orientation relative to the substrate crystal structure. Epitaxy can involve single-crystal structures, although grain-to-grain epitaxy has been observed in granular films. For most technological applications, single-domain epitaxy, which is the growth of an overlayer crystal with one well-defined orientation with respect to the substrate crystal, is preferred. Epitaxy can also play an important role in the growth of superlattice structures.

<span class="mw-page-title-main">Calcium silicate</span> Chemical compound naturally occurring as the mineral larnite

Calcium silicate can refer to several silicates of calcium including:

<span class="mw-page-title-main">Dangling bond</span> State of an immobilized atom in chemistry

In chemistry, a dangling bond is an unsatisfied valence on an immobilized atom. An atom with a dangling bond is also referred to as an immobilized free radical or an immobilized radical, a reference to its structural and chemical similarity to a free radical.

The pedosphere is the outermost layer of the Earth that is composed of soil and subject to soil formation processes. It exists at the interface of the lithosphere, atmosphere, hydrosphere and biosphere. The pedosphere is the skin of the Earth and only develops when there is a dynamic interaction between the atmosphere, biosphere, lithosphere and the hydrosphere. The pedosphere is the foundation of terrestrial life on Earth.

<span class="mw-page-title-main">Photocatalysis</span> Acceleration of a photoreaction in the presence of a catalyst

In chemistry, photocatalysis is the acceleration of a photoreaction in the presence of a photocatalyst, the excited state of which "repeatedly interacts with the reaction partners forming reaction intermediates and regenerates itself after each cycle of such interactions." In many cases, the catalyst is a solid that upon irradiation with UV- or visible light generates electron–hole pairs that generate free radicals. Photocatalysts belong to three main groups; heterogeneous, homogeneous, and plasmonic antenna-reactor catalysts. The use of each catalysts depends on the preferred application and required catalysis reaction.

<span class="mw-page-title-main">Cerium(IV) oxide</span> Chemical compound

Cerium(IV) oxide, also known as ceric oxide, ceric dioxide, ceria, cerium oxide or cerium dioxide, is an oxide of the rare-earth metal cerium. It is a pale yellow-white powder with the chemical formula CeO2. It is an important commercial product and an intermediate in the purification of the element from the ores. The distinctive property of this material is its reversible conversion to a non-stoichiometric oxide.

<span class="mw-page-title-main">Halloysite</span> Aluminosilicate clay mineral

Halloysite is an aluminosilicate clay mineral with the empirical formula Al2Si2O5(OH)4. Its main constituents are oxygen (55.78%), silicon (21.76%), aluminium (20.90%), and hydrogen (1.56%). It is a member of the kaolinite group. Halloysite typically forms by hydrothermal alteration of alumino-silicate minerals. It can occur intermixed with dickite, kaolinite, montmorillonite and other clay minerals. X-ray diffraction studies are required for positive identification. It was first described in 1826, and subsequently named after, the Belgian geologist Omalius d'Halloy.

<span class="mw-page-title-main">Tetraethyl orthosilicate</span> Chemical compound

Tetraethyl orthosilicate, formally named tetraethoxysilane (TEOS), ethyl silicate is the organic chemical compound with the formula Si(OC2H5)4. TEOS is a colorless liquid. It degrades in water. TEOS is the ethyl ester of orthosilicic acid, Si(OH)4. It is the most prevalent alkoxide of silicon.

<span class="mw-page-title-main">Silicon monoxide</span> Chemical compound

Silicon monoxide is the chemical compound with the formula SiO where silicon is present in the oxidation state +2. In the vapour phase, it is a diatomic molecule. It has been detected in stellar objects and has been described as the most common oxide of silicon in the universe.

<span class="mw-page-title-main">Carbonate–silicate cycle</span> Geochemical transformation of silicate rocks

The carbonate–silicate geochemical cycle, also known as the inorganic carbon cycle, describes the long-term transformation of silicate rocks to carbonate rocks by weathering and sedimentation, and the transformation of carbonate rocks back into silicate rocks by metamorphism and volcanism. Carbon dioxide is removed from the atmosphere during burial of weathered minerals and returned to the atmosphere through volcanism. On million-year time scales, the carbonate-silicate cycle is a key factor in controlling Earth's climate because it regulates carbon dioxide levels and therefore global temperature.

<span class="mw-page-title-main">Bismuth silicon oxide</span> Chemical compound

Bismuth silicon oxide is a solid inorganic compound of bismuth, silicon and oxygen. Its most common chemical formula is Bi12SiO20, though other compositions are also known. It occurs naturally as the mineral sillénite and can be produced synthetically, by heating a mixture of bismuth and silicon oxides. Centimeter-sized single crystals of Bi12SiO20 can be grown by the Czochralski process from the molten phase. They exhibit piezoelectric, electro-optic, elasto-optic, photorefractive and photoconductive properties, and therefore have potential applications in spatial light modulators, acoustic delay lines and hologram recording equipment. Bi12SiO20 can be obtained as a whitish powder with band gap of approximately 3.2 eV starting from bismuth subcarbonate and silica in presence of ethyleneglycol. 29Si solid-state NMR is used to proof that the Si(IV) cations are sharing oxygen atoms with the Bi(III) cations. The 29Si chemical shift (δ) in Bi12SiO20 is −78.1 ppm. Unlike the bismuth oxide, the presence of the acidic Si(IV) cations avoid the reactivity with CO2.

Mechanically stimulated gas emission (MSGE) is a complex phenomenon embracing various physical and chemical processes occurring on the surface and in the bulk of a solid under applied mechanical stress and resulting in emission of gases. MSGE is a part of a more general phenomenon of mechanically stimulated neutral emission. MSGE experiments are often performed in ultra-high vacuum.

<span class="mw-page-title-main">Jimthompsonite</span>

Jimthompsonite is a magnesium iron silicate mineral with chemical formula (Mg,Fe2+)5Si6O16(OH)2. It is a triple chain silicate (or inosilicate) along with clinojimthompsonite and chesterite. They were described in 1977 by Burham and Veblen. They attracted great mineralogical attention because they were the first examples of new chain silicate structures among a large group known as biopyriboles whose name is derived from the words biotite, pyroxene, and amphiboles.

<span class="mw-page-title-main">Energetically modified cement</span> Class of cements, mechanically processed to transform reactivity

Energetically modified cements (EMCs) are a class of cements made from pozzolans, silica sand, blast furnace slag, or Portland cement. The term "energetically modified" arises by virtue of the mechanochemistry process applied to the raw material, more accurately classified as "high energy ball milling" (HEBM). At its simplest this means a milling method that invokes high kinetics by subjecting "powders to the repeated action of hitting balls" as compared to (say) the low kinetics of rotating ball mills. This causes, amongst others, a thermodynamic transformation in the material to increase its chemical reactivity. For EMCs, the HEBM process used is a unique form of specialised vibratory milling discovered in Sweden and applied only to cementitious materials, here called "EMC Activation".

<span class="mw-page-title-main">Heterogeneous gold catalysis</span>

Heterogeneous gold catalysis refers to the use of elemental gold as a heterogeneous catalyst. As in most heterogeneous catalysis, the metal is typically supported on metal oxide. Furthermore, as seen in other heterogeneous catalysts, activity increases with a decreasing diameter of supported gold clusters. Several industrially relevant processes are also observed such as H2 activation, Water-gas shift reaction, and hydrogenation. One or two gold-catalyzed reactions may have been commercialized.

<span class="mw-page-title-main">Silica cycle</span> Biogeochemical cycle

The silica cycle is the biogeochemical cycle in which biogenic silica is transported between the Earth's systems. Silicon is one of the most abundant elements on Earth, and is considered necessary for life. The silica cycle has significant overlap with the carbon cycle and plays an important role in the sequestration of carbon through continental weathering, biogenic export and burial as oozes on geologic timescales.

References

  1. ↑ Beyer, Martin K.; Clausen-Schaumann, Hauke (2005). "Mechanochemistry: The Mechanical Activation of Covalent Bonds". Chemical Reviews. 105 (8): 2921–2948. doi:10.1021/cr030697h. PMID   16092823.
  2. ↑ Drexler, K. Eric (1992). Nanosystems: Molecular Machinery, Manufacturing, and Computation. New York: John Wiley & Sons. ISBN   978-0-471-57547-4.
  3. ↑ Batelle Memorial Institute and Foresight Nanotech Institute. "Technology Roadmap for Productive Nanosystems" (PDF). Retrieved 23 February 2013.
  4. 1 2 3 4 Kita, Itsuro; Matsuo, Sadao; Wakita, Hiroshi (1982-12-10). "H 2 generation by reaction between H 2 O and crushed rock: An experimental study on H 2 degassing from the active fault zone". Journal of Geophysical Research: Solid Earth. 87 (B13): 10789–10795. Bibcode:1982JGR....8710789K. doi:10.1029/JB087iB13p10789.
  5. 1 2 3 4 5 Telling, J.; Boyd, E. S.; Bone, N.; Jones, E. L.; Tranter, M.; MacFarlane, J. W.; Martin, P. G.; Wadham, J. L.; Lamarche-Gagnon, G.; Skidmore, M. L.; Hamilton, T. L.; Hill, E.; Jackson, M.; Hodgson, D. A. (November 2015). "Rock comminution as a source of hydrogen for subglacial ecosystems". Nature Geoscience. 8 (11): 851–855. Bibcode:2015NatGe...8..851T. doi:10.1038/ngeo2533. hdl: 1983/826fdf87-589b-4a98-9325-54cc25bdb23d . ISSN   1752-0908.
  6. 1 2 3 4 5 6 7 Stone, Jordan; Edgar, John O.; Gould, Jamie A.; Telling, Jon (2022-08-08). "Tectonically-driven oxidant production in the hot biosphere". Nature Communications. 13 (1): 4529. Bibcode:2022NatCo..13.4529S. doi:10.1038/s41467-022-32129-y. ISSN   2041-1723. PMC   9360021 . PMID   35941147.
  7. ↑ Marchini, Marianna; Gandolfi, Massimo; Maini, Lucia; Raggetti, Lucia; Martelli, Matteo (2022). "Exploring the ancient chemistry of mercury". Proceedings of the National Academy of Sciences. 119 (24): e2123171119. Bibcode:2022PNAS..11923171M. doi: 10.1073/pnas.2123171119 . PMC   9214491 . PMID   35671430. S2CID   249464844.
  8. ↑ "Front cover". Chemical Society Reviews. 42 (18): 7487. 2013. doi:10.1039/c3cs90071a. ISSN   0306-0012.
  9. ↑ McMahon, Sean; Parnell, John; Blamey, Nigel J.F. (September 2016). "Evidence for Seismogenic Hydrogen Gas, a Potential Microbial Energy Source on Earth and Mars". Astrobiology. 16 (9): 690–702. Bibcode:2016AsBio..16..690M. doi:10.1089/ast.2015.1405. hdl: 2164/9255 . ISSN   1531-1074. PMID   27623198.
  10. ↑ "Mineral defects: a driving force for (bio)geochemical reactions? | Frontiers Research Topic". www.frontiersin.org. Retrieved 2022-12-09.
  11. ↑ He, Hongping; Wu, Xiao; Xian, Haiyang; Zhu, Jianxi; Yang, Yiping; Lv, Ying; Li, Yiliang; Konhauser, Kurt O. (2021-11-16). "An abiotic source of Archean hydrogen peroxide and oxygen that pre-dates oxygenic photosynthesis". Nature Communications. 12 (1): 6611. Bibcode:2021NatCo..12.6611H. doi:10.1038/s41467-021-26916-2. ISSN   2041-1723. PMC   8595356 . PMID   34785682. S2CID   240601612.
  12. ↑ Hickenboth, Charles R.; Moore, Jeffrey S.; White, Scott R.; Sottos, Nancy R.; Baudry1, Jerome; Wilson, Scott R. (2007). "Biasing Reaction Pathways with Mechanical Force". Nature . 446 (7134): 423–427. Bibcode:2007Natur.446..423H. doi:10.1038/nature05681. PMID   17377579. S2CID   4427747.{{cite journal}}: CS1 maint: numeric names: authors list (link)(subscription required)
  13. ↑ Carlier, Leslie; Baron, Michel; Chamayou, Alain; Couarraze, Guy (May 2013). "Greener pharmacy using solvent-free synthesis: Investigation of the mechanism in the case of dibenzophenazine". Powder Technology. 240: 41–47. doi:10.1016/j.powtec.2012.07.009. ISSN   0032-5910. S2CID   97605147.
  14. ↑ Carlier, Leslie; Baron, Michel; Chamayou, Alain; Couarraze, Guy (2011-10-27). "ChemInform Abstract: Use of Co-Grinding as a Solvent-Free Solid State Method to Synthesize Dibenzophenazines". ChemInform. 42 (47): no. doi:10.1002/chin.201147164. ISSN   0931-7597.
  15. ↑ Salmatonidis, A.; Hesselbach, J.; Lilienkamp, G.; Graumann, T.; Daum, W.; Kwade, A.; Garnweitner, G. (2018-05-29). "Chemical Cross-Linking of Anatase Nanoparticle Thin Films for Enhanced Mechanical Properties". Langmuir. 34 (21): 6109–6116. doi:10.1021/acs.langmuir.8b00479. ISSN   0743-7463. PMID   29722536.
  16. ↑ Gonnet, Lori; Lennox, Cameron B.; Do, Jean-Louis; Malvestiti, Ivani; Koenig, Stefan G.; Nagapudi, Karthik; Friščić, Tomislav (2022-03-21). "Metal-Catalyzed Organic Reactions by Resonant Acoustic Mixing**". Angewandte Chemie International Edition. 61 (13): e202115030. doi:10.1002/anie.202115030. PMID   35138018.
  17. ↑ Chaudhary, V., et al., ChemPhysChem (2018) 19 (18), 2370, https://onlinelibrary.wiley.com/doi/abs/10.1002/cphc.201800318
  18. ↑ Lim, Xiaozhi (July 18, 2016). "Grinding Chemicals Together in an Effort to be Greener". The New York Times. ISSN   0362-4331 . Retrieved August 6, 2016.
  19. ↑ Oliveira, P. F. M.; Baron, M.; Chamayou, A.; André-Barrès, C.; Guidetti, B.; Baltas, M. (2014-10-17). "Solvent-free mechanochemical route for green synthesis of pharmaceutically attractive phenol-hydrazones". RSC Adv. 4 (100): 56736–56742. Bibcode:2014RSCAd...456736O. doi:10.1039/c4ra10489g. ISSN   2046-2069. S2CID   98039624.
  20. ↑ Bak, Ebbe N.; Zafirov, Kaloyan; Merrison, Jonathan P.; Jensen, Svend J. Knak; Nørnberg, Per; Gunnlaugsson, Haraldur P.; Finster, Kai (2017-09-01). "Production of reactive oxygen species from abraded silicates. Implications for the reactivity of the Martian soil". Earth and Planetary Science Letters. 473: 113–121. Bibcode:2017E&PSL.473..113B. doi:10.1016/j.epsl.2017.06.008. ISSN   0012-821X.
  21. ↑ Baláž, Peter; Achimovičová, Marcela; Baláž, Matej; Billik, Peter; Cherkezova-Zheleva, Zara; Criado, José Manuel; Delogu, Francesco; Dutková, Erika; Gaffet, Eric; Gotor, Francisco José; Kumar, Rakesh (2013-08-19). "Hallmarks of mechanochemistry: from nanoparticles to technology". Chemical Society Reviews. 42 (18): 7571–7637. doi:10.1039/C3CS35468G. hdl: 10261/96958 . ISSN   1460-4744. PMID   23558752.
  22. ↑ Chaudhary, Varun; Zhong, Yaoying; Parmar, Harshida; Sharma, Vinay; Tan, Xiao; Ramanujan, Raju V. (August 2018). "Mechanochemical Synthesis of Iron and Cobalt Magnetic Metal Nanoparticles and Iron/Calcium Oxide and Cobalt/Calcium Oxide Nanocomposites". ChemistryOpen. 7 (8): 590–598. doi:10.1002/open.201800091. PMC   6080568 . PMID   30094125.
  23. ↑ S. Makarov, Anton; Rueping, Magnus (2025). "Scalable depolymerizing transesterification and amidation of (poly)lactic acid (PLA) enabled by resonant acoustic mixing (RAM)". Green Chemistry. 27 (3): 716–721. doi: 10.1039/D4GC04623D .
  24. ↑ "Mechanochemical breakthrough unlocks cheap, safe, powdered hydrogen". New Atlas. 2022-07-19. Retrieved 2022-07-19.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.