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Polymer Physics
Polymer physics is the field of physics that studies polymers, their fluctuations, mechanical properties, as well as the kinetics of reactions involving degradation and polymerisation of polymers and monomers respectively.P. Flory, ''Principles of Polymer Chemistry'', Cornell University Press, 1953. .Pierre Gilles De Gennes, ''Scaling Concepts in Polymer Physics'' CORNELL UNIVERSITY PRESS Ithaca and London, 1979M. Doi and S. F. Edwards, ''The Theory of Polymer Dynamics'' Oxford University Inc NY, 1986 While it focuses on the perspective of condensed matter physics, polymer physics is originally a branch of statistical physics. Polymer physics and polymer chemistry are also related with the field of polymer science, where this is considered the applicative part of polymers. Polymers are large molecules and thus are very complicated for solving using a deterministic method. Yet, statistical approaches can yield results and are often pertinent, since large polymers (i.e., polymers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of phys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Size Exclusion Chromatography
Size-exclusion chromatography (SEC), also known as molecular sieve chromatography, is a chromatographic method in which molecules in solution are separated by their size, and in some cases molecular weight. It is usually applied to large molecules or macromolecular complexes such as proteins and industrial polymers. Typically, when an aqueous solution is used to transport the sample through the column, the technique is known as gel-filtration chromatography, versus the name gel permeation chromatography, which is used when an organic solvent is used as a mobile phase. The chromatography column is packed with fine, porous beads which are commonly composed of dextran, agarose, or polyacrylamide polymers. The pore sizes of these beads are used to estimate the dimensions of macromolecules. SEC is a widely used polymer characterization method because of its ability to provide good molar mass distribution (Mw) results for polymers. Applications The main application of gel-filtration chr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excluded Volume
The concept of excluded volume was introduced by Werner Kuhn in 1934 and applied to polymer molecules shortly thereafter by Paul Flory. Excluded volume gives rise to depletion forces. In liquid state theory In liquid state theory, the 'excluded volume' of a molecule is the volume that is inaccessible to other molecules in the system as a result of the presence of the first molecule. The excluded volume of a hard sphere is eight times its volume—however, for a two-molecule system, this volume is distributed among the two particles, giving the conventional result of four times the volume; this is an important quantity in the Van der Waals equation of state. The calculation of the excluded volume for particles with non-spherical shapes is usually difficult, since it depends on the relative orientation of the particles. The distance of closest approach of hard ellipses and their excluded area has been recently considered. In polymer science In polymer science, excluded volume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistence Length
The persistence length is a basic mechanical property quantifying the bending stiffness of a polymer. The molecule behaves like a flexible elastic rod/beam (beam theory). Informally, for pieces of the polymer that are shorter than the persistence length, the molecule behaves like a rigid rod, while for pieces of the polymer that are much longer than the persistence length, the properties can only be described statistically, like a three-dimensional random walk. Formally, the persistence length, ''P'', is defined as the length over which correlations in the direction of the tangent are lost. In a more chemical based manner it can also be defined as the average sum of the projections of all bonds j ≥ i on bond i in an infinitely long chain. Let us define the angle ''θ'' between a vector that is tangent to the polymer at position 0 (zero) and a tangent vector at a distance ''L'' away from position 0, along the contour of the chain. It can be shown that the expectation value o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Worm-like Chain
The worm-like chain (WLC) model in polymer physics is used to describe the behavior of polymers that are semi-flexible: fairly stiff with successive segments pointing in roughly the same direction, and with persistence length within a few orders of magnitude of the polymer length. The WLC model is the continuous version of the Kratky– Porod model. Model elements The WLC model envisions a continuously flexible isotropic rod. This is in contrast to the freely-jointed chain model, which is only flexible between discrete freely hinged segments. The model is particularly suited for describing stiffer polymers, with successive segments displaying a sort of cooperativity: nearby segments are roughly aligned. At room temperature, the polymer adopts a smoothly curved conformation; at T = 0 K, the polymer adopts a rigid rod conformation. For a polymer of maximum length L_0, parametrize the path of the polymer as s \in(0,L_0). Allow \hat t(s) to be the unit tangent vector to the chain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boltzmann Factor
Factor, a Latin word meaning "who/which acts", may refer to: Commerce * Factor (agent), a person who acts for, notably a mercantile and colonial agent * Factor (Scotland), a person or firm managing a Scottish estate * Factors of production, such a factor is a resource used in the production of goods and services Science and technology Biology * Coagulation factors, substances essential for blood coagulation * Environmental factor, any abiotic or biotic factor that affects life * Enzyme, proteins that catalyze chemical reactions * Factor B, and factor D, peptides involved in the alternate pathway of immune system complement activation * Transcription factor, a protein that binds to specific DNA sequences Computer science and information technology * Factor (programming language), a concatenative stack-oriented programming language * Factor (Unix), a utility for factoring an integer into its prime factors * Factor, a substring, a subsequence of consecutive symbols in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vladimir Pokrovskii
Vladimir Nikolajevich Pokrovskii (russian: Влад’имир Никол’аевич Покр’овский; born 11 May 1934) is a Russian scientist known for his original contributions to polymer physics and economic theory. He was the founder of the Altai (Russia, Barnaul) school of dynamics of nonlinear fluids (Yurii Altukhov, Grigorii Pyshnograi and others). Biography Pokrovskii was born May 11, 1934 into a Russian family in the rural locality Altayskoye, Altaysky District, Altai Krai (Russian: Алтайское, Алтайского края), Russia. He graduated from Tomsk State University in Siberia as a physicist (Department of Theoretical Physics) in 1958 and in the same year was employed as a teacher of physics at Tomsk Polytechnic University. In 1964 he moved to the Branch of Institute of Chemical Physics of the Academy of Sciences of the USSR (Chernogolovka, Moscow region) where in positions of Senior Research Fellow was engaged in studying of suspensio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ilya Lifshitz
Ilya Mikhailovich Lifshitz (russian: Илья́ Миха́йлович Ли́фшиц; January 13, 1917 – October 23, 1982) was a leading Soviet theoretical physicist, brother of Evgeny Lifshitz. He is known for his works in solid state physics, electron theory of metals, disordered systems, and the theory of polymers. Work Ilya Lifshitz was born into a Ukrainian Jewish family in Kharkov, Kharkov Governorate, Russian Empire (now Kharkiv, Ukraine). Together with Arnold Kosevich, in 1954 Lifshitz established the connection between the oscillation of magnetic characteristics of metals and the form of an electronic surface of Fermi ( Lifshitz–Kosevich formula) from de Haas–van Alphen experiments. Lifshitz was one of the founders of the theory of disordered systems. He introduced some of the basic notions, such as self-averaging, and discovered what is now called Lifshitz tails and Lifshitz singularity. In perturbation theory, Lifshitz introduced the notion of spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sam Edwards (physicist)
Sir Samuel Frederick Edwards (1 February 1928 – 7 May 2015) was a Welsh physicist. The Sam Edwards Medal and Prize is named in his honour. Early life and studies Edwards was born on 1 February 1928 in Swansea, Wales, the son of Richard and Mary Jane Edwards. He was educated at the Bishop Gore School, Swansea, and Gonville and Caius College, Cambridge, the University of Manchester, and at Harvard University, in the United States. He wrote his thesis under Julian Schwinger on the structure of the electron, and subsequently developed the functional integral form of field theory. Academic research Edwards's work in condensed matter physics started in 1958 with a paper which showed that statistical properties of disordered systems (glasses, gels etc.) could be described by the Feynman diagram and path integral methods invented in quantum field theory. During the following 35 years Edwards worked in the theoretical study of complex materials, such as polymers, gels, colloids an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Masao Doi
(born 29 March 1948) is a Professor Emeritus at Nagoya University and The University of Tokyo. He is a Fellow of the Toyota Physical and Chemical Research Institute. In 1978 and 1979 he wrote a series of papers with Sir Sam Edwards expanding on the concept of reptation introduced by Pierre-Gilles de Gennes in 1971. In 1996 he authored the textbook ''Introduction to Polymer Physics''. In 2001 the American Physical Society awarded Doi the Polymer Physics Prize for "pioneering contributions to the theory of dynamics and rheology of entangled polymers and complex fluids." He was also awarded the Bingham Medal in 2001 by the Society of Rheology. In 2016, he was elected a member of the National Academy of Engineering The National Academy of Engineering (NAE) is an American nonprofit, non-governmental organization. The National Academy of Engineering is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of ... for contributi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre-Gilles De Gennes
Pierre-Gilles de Gennes (; 24 October 1932 – 18 May 2007) was a French physicist and the Nobel Prize laureate in physics in 1991. Education and early life He was born in Paris, France, and was home-schooled to the age of 12. By the age of 13, he had adopted adult reading habits and was visiting museums. Later, de Gennes studied at the École Normale Supérieure. After leaving the ''École'' in 1955, he became a research engineer at the Saclay center of the Commissariat à l'Énergie Atomique, working mainly on neutron scattering and magnetism, with advice from Anatole Abragam and Jacques Friedel. He defended his Ph.D. in 1957 at the University of Paris. Career and research In 1959, he was a postdoctoral research visitor with Charles Kittel at the University of California, Berkeley, and then spent 27 months in the French Navy. In 1961, he was assistant professor in Orsay and soon started the Orsay group on superconductors. In 1968, he switched to studying liquid cry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Flory
Paul John Flory (June 19, 1910 – September 9, 1985) was an American chemist and Nobel laureate who was known for his work in the field of polymers, or macromolecules. He was a leading pioneer in understanding the behavior of polymers in solution, and won the Nobel Prize in Chemistry in 1974 "for his fundamental achievements, both theoretical and experimental, in the physical chemistry of macromolecules". Biography Personal life Flory was born in Sterling, Illinois, on June 19, 1910. He was raised by Ezra Flory and Nee Martha Brumbaugh. His father worked as a clergyman-educator, and his mother was a school teacher. He first gained his interest in science from Carl W Holl, who was a professor in chemistry. Holl was employed in Indiana at Manchester College as a chemistry professor. In 1936, he married Emily Catherine Tabor. He and Emily had three children together; Susan Springer, Melinda Groom and Paul John Flory jr. They also had five grandchildren. All of his children pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
