In chemistry, solvatochromism is the phenomenon observed when the colour of a solution is different when the solute is dissolved in different solvents.
Nanochemistry is an emerging sub-discipline of the chemical and material sciences that deals with the development of new methods for creating nanoscale materials. The term "nanochemistry" was first used by Ozin in 1992 as 'the uses of chemical synthesis to reproducibly afford nanomaterials from the atom "up", contrary to the nanoengineering and nanophysics approach that operates from the bulk "down"'. Nanochemistry focuses on solid-state chemistry that emphasizes synthesis of building blocks that are dependent on size, surface, shape, and defect properties, rather than the actual production of matter. Atomic and molecular properties mainly deal with the degrees of freedom of atoms in the periodic table. However, nanochemistry introduced other degrees of freedom that controls material's behaviors by transformation into solutions. Nanoscale objects exhibit novel material properties, largely as a consequence of their finite small size. Several chemical modifications on nanometer-scaled structures approve size dependent effects.
Silver selenide (Ag2Se) is the reaction product formed when selenium toning analog silver gelatine photo papers in photographic print toning. The selenium toner contains sodium selenite (Na2SeO3) as one of its active ingredients, which is the source of the selenide (Se2−) anion combining with the silver in the toning process.
Louis Edward Brus is an American chemist, and currently the Samuel Latham Mitchell Professor of Chemistry at Columbia University. He is the co-discoverer of the colloidal semi-conductor nanocrystals known as quantum dots. In 2023, he was awarded the Nobel Prize in Chemistry.
Oleylamine is an organic compound with a molecular formula C18H35NH2. It is an unsaturated fatty amine related to the fatty acid oleic acid. The pure compound is a clear and colorless liquid. Commercially available oleylamine reagents vary in color from clear and colorless to varying degrees of yellow due to impurities. The major impurities include trans isomer (elaidylamine) and other long chain amines with varying chain lengths. Minor impurities include oxygen-containing substances such as amides and nitroalkanes.
Younan Xia is a Chinese-American chemist, materials scientist, and bioengineer. He is the Brock Family Chair and Georgia Research Alliance (GRA) Eminent Scholar in Nanomedicine in the Wallace H. Coulter Department of Biomedical Engineering, with joint appointments in the School of Chemistry & Biochemistry, the School of Chemical & Biomolecular Engineering, and Parker H. Petit Institute for Bioengineering & Bioscience at the Georgia Institute of Technology.
Core–shell semiconducting nanocrystals (CSSNCs) are a class of materials which have properties intermediate between those of small, individual molecules and those of bulk, crystalline semiconductors. They are unique because of their easily modular properties, which are a result of their size. These nanocrystals are composed of a quantum dot semiconducting core material and a shell of a distinct semiconducting material. The core and the shell are typically composed of type II–VI, IV–VI, and III–V semiconductors, with configurations such as CdS/ZnS, CdSe/ZnS, CdSe/CdS, and InAs/CdSe Organically passivated quantum dots have low fluorescence quantum yield due to surface related trap states. CSSNCs address this problem because the shell increases quantum yield by passivating the surface trap states. In addition, the shell provides protection against environmental changes, photo-oxidative degradation, and provides another route for modularity. Precise control of the size, shape, and composition of both the core and the shell enable the emission wavelength to be tuned over a wider range of wavelengths than with either individual semiconductor. These materials have found applications in biological systems and optics.
Blinking colloidal nanocrystals is a phenomenon observed during studies of single colloidal nanocrystals that show that they randomly turn their photoluminescence on and off even under continuous light illumination. This has also been described as luminescence intermittency. Similar behavior has been observed in crystals made of other materials. For example, porous silicon also exhibits this affect.
A localized surface plasmon (LSP) is the result of the confinement of a surface plasmon in a nanoparticle of size comparable to or smaller than the wavelength of light used to excite the plasmon. When a small spherical metallic nanoparticle is irradiated by light, the oscillating electric field causes the conduction electrons to oscillate coherently. When the electron cloud is displaced relative to its original position, a restoring force arises from Coulombic attraction between electrons and nuclei. This force causes the electron cloud to oscillate. The oscillation frequency is determined by the density of electrons, the effective electron mass, and the size and shape of the charge distribution. The LSP has two important effects: electric fields near the particle's surface are greatly enhanced and the particle's optical absorption has a maximum at the plasmon resonant frequency. Surface plasmon resonance can also be tuned based on the shape of the nanoparticle. The plasmon frequency can be related to the metal dielectric constant. The enhancement falls off quickly with distance from the surface and, for noble metal nanoparticles, the resonance occurs at visible wavelengths. Localized surface plasmon resonance creates brilliant colors in metal colloidal solutions.
Cheon Jinwoo is the H.G. Underwood Professor at Yonsei University and the Director of the Center for Nanomedicine, Institute for Basic Science (IBS). As a leading chemist in inorganic materials chemistry and nanomedicine Cheon and his group research chemical principles for the preparation of complex inorganic materials. He has been a Clarivate Analytics Highly Cited Researcher both in the field of chemistry in 2014, 2015, 2016 and cross-field in 2018. He is a fellow of the American Chemical Society, Royal Society of Chemistry, and Korean Academy of Science and Technology, a senior editor of Accounts of Chemical Research and an editorial advisory board member of Journal of Materials Chemistry, Nano Letters and Materials Horizons.
A nanosheet is a two-dimensional nanostructure with thickness in a scale ranging from 1 to 100 nm.
Delia J. Milliron is the T. Brockett Hudson Professor in Chemical Engineering at the University of Texas at Austin. Milliron leads a research team that focuses on developing and studying the properties of new electronic nanomaterials. Her team pursues studies on nanocrystals, nanoscale interfaces, and controlled assemblies of nanocrystals. Her team takes a systematic approach towards elucidating effects that arise at the nanoscale with a special focus on structure-property relationships.
Sara E. Skrabalak is a James H. Rudy Professor at Indiana University. Skrabalak leads a research group in the department of chemistry which focuses on the development of new nanomaterials. She has an adjunct appointment in the department of intelligent systems engineering.
Susan M. Kauzlarich is an American chemist and is presently a distinguished professor of chemistry at the University of California, Davis. At UC Davis, Kauzlarich leads a research group focused on the synthesis and characterization of Zintl phases and nanoclusters with applications in the fields of thermoelectric materials, magnetic resonance imaging, energy storage, opto-electronics, and drug delivery. Kauzlarich has published over 250 peer-reviewed publications and has been awarded several patents. In 2009, Kauzlarich received the annual Presidential Award for Excellence in Science, Mathematics and Engineering Mentoring, which is administered by the National Science Foundation to acknowledge faculty members who raise the membership of minorities, women and disabled students in the science and engineering fields. In January 2022 she became Deputy Editor for the scientific journal, Science Advances. She gave the Edward Herbert Boomer Memorial Lecture of the University of Alberta in 2023.
Maksym V. Kovalenko is a full professor of inorganic chemistry and the head of the Functional Inorganic Materials group at ETH Zurich. A part of the research activities of the group are conducted at Empa (Dübendorf). He is working in the fields of solid-state chemistry, quantum dots and other nanomaterials, surface chemistry, self-assembly, optical spectroscopy, optoelectronics and energy storage.
Perovskite nanocrystals are a class of semiconductor nanocrystals, which exhibit unique characteristics that separate them from traditional quantum dots. Perovskite nanocrystals have an ABX3 composition where A = cesium, methylammonium (MA), or formamidinium (FA); B = lead or tin; and X = chloride, bromide, or iodide.
Uri Banin is an Israeli nanotechnologist and physical chemist and a professor at the Hebrew University of Jerusalem, currently holding the Alfred & Erica Larisch Memorial Chair at the Institute of Chemistry. He is recognized as one of the pioneers of nanoscience in Israel.
Silicon quantum dots are metal-free biologically compatible quantum dots with photoluminescence emission maxima that are tunable through the visible to near-infrared spectral regions. These quantum dots have unique properties arising from their indirect band gap, including long-lived luminescent excited-states and large Stokes shifts. A variety of disproportionation, pyrolysis, and solution protocols have been used to prepare silicon quantum dots, however it is important to note that some solution-based protocols for preparing luminescent silicon quantum dots actually yield carbon quantum dots instead of the reported silicon. The unique properties of silicon quantum dots lend themselves to an array of potential applications: biological imaging, luminescent solar concentrators, light emitting diodes, sensors, and lithium-ion battery anodes.
Efrat Lifshitz is an Israeli chemist at the Schulich Faculty of Chemistry and the Solid-State Institute, Technion – Israel Institute of Technology (Technion-IIT). Lifshitz's research is known for pioneering advances in developing and studying low-dimensional semiconductors by exploring the relationship between their optical properties and magnetism.
Maria Ibáñez Sabaté is a Spanish materials scientist and Professor at the Institute of Science and Technology Austria. Her research considers functional nanomaterials for next generation technologies. She was awarded the ETH Zurich Ružička Prize in 2017.
