Bruno H. Zimm

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Bruno Hasbrouck Zimm (born October 31, 1920 in Kingston (New York) , † November 26, 2005 in La Jolla ) was an American chemist who dealt with the physical chemistry of polymers and proteins and DNA .

Life

Zimmer studied at Columbia University with a bachelor's degree in 1941, a master's degree in 1943 and his doctorate in 1944 with Joseph E. Mayer . He was then an instructor at the Polytechnic Institute of Brooklyn with Hermann F. Mark and from 1946 at the University of California, Berkeley , where he dealt with light scattering and introduced the Zimm plot. In Berkeley he was an assistant professor and an associate professor from 1950 to 1952. From 1951 to 1960 he was at the Research Laboratories of General Electric in Schenectady. From 1960 he was a full professor at the University of California, San Diego . In 1991 he retired.

1950/51 he was visiting professor at Harvard University and 1960 at Yale University . Most recently he was a scientific advisor to Wyatt Technology Corporation.

plant

Zimmer worked both experimentally and theoretically. From his training at Mayer, he had a focus on statistical mechanics. During his time with Herman Mark at the Polytechnic Institute in Brooklyn, he developed the Zimm plot, which enables the simultaneous determination of the molar mass and shape (using the second virial coefficient and the radius of gyration) of polymers using light scattering . In his publication in 1948 he also stated the construction principles (including electronic circuit diagrams) of a new photometer. His interest in light scattering arose during World War II while working on a military-related project on light scattering on smoke using the Einstein - Smoluchowski theory. After hearing that Peter Debye determined the molecular weights of polymers with light scattering in an as yet unpublished work, Zimm and his colleague Paul Doty (also a PhD student from Mayer) applied this to polymers.

The Zimm model (see Rouse model ) for the dynamics of polymers was introduced by him in 1956. The Zimm-Bragg model was published by Zimm and JK Bragg in 1959 and describes the transition of a protein into a helix structure in statistical mechanics. It corresponds to a one-dimensional Ising model . In 1960 he developed a theory of the melting of DNA helices.

From around 1960 he dealt with the physical chemistry of DNA. In order to measure the length of DNA molecules, he developed a viscometer with rotating cylinders in the 1960s. This enabled him to determine the correct length values ​​first for the DNA of phages, then for E. Coli and finally for the chromosomes of Drosophila. He also studied the diffusion of DNA during gel electrophoresis and the interaction of the DNA with the ion background in solution.

Honors and memberships

He was a member of the National Academy of Sciences and the American Academy of Arts and Sciences . In 1953 he became a Fellow of the American Physical Society .

literature

Individual evidence

  1. ↑ Life data according to American Men and Women of Science , Thomson Gale 2004.
  2. ↑ Zimm himself referred to it as a reciprocal-intensity light-scattering plot , obituary in Biographical Memoirs NAS.
  3. ↑ Zimm The scattering of light and the radial distribution function of high polymer solutions , J. Chem. Phys. 16, 1948, 1093-1099.
  4. ↑ Zimm Apparatus and methods for measurement and interpretation of the angular variation of light scattering; preliminary results on polystyrene solutions , J. Chem. Phys. 16, 1948, 1099-1116.
  5. ↑ Zimm, WH Stockmayer The dimensions of chain molecules containing branches and rings , J. Chem. Phys., 17, 1949, 1301-1314.
  6. ↑ Published in J. Chem. Phys. 1944.
  7. ↑ Mark, Zimm Some light scattering experiments with high-polymer solutions , J. Chem. Phys. 12, 1944, 144-145
  8. ↑ PM Doty, H. Mark, Zimm An investigation of the determination of molecular weights of high polymers by light scattering , J. Chem. Phys. 13, 1945, 159-166.
  9. ↑ Zimm Dynamics of polymer molecules in dilute solutions: viscoelasticity, flow birefringence and dielectric loss , J. Chem. Phys. 24, 1956, 269-278.
  10. ↑ Zimm, JK Bragg Theory of the Phase Transition between Helix and Random Coil in Polypeptide Chains , Journal of Chemical Physics 31, 1959, pp. 526-531.
  11. ↑ Zimm Theory of melting of the helical form in double strains of the DNA type , J. Chem. Phys., 33, 1960, 1349-1356.
  12. ^ DM Crothers, Zimm Simplified rotating cylinder viscosimeter for deoxyribonucleic acid , Proc. Nat. Acad. Sci. 48, 1962, 905-911.
  13. ↑ R. Kavenoff, Zimm Chromosome-sized DNA molecules from Drosophila , Chromosoma, 41, 1973, 1-27.
  14. ^ American Academy of Arts and Sciences. Book of Members ( PDF ). Retrieved April 21, 2016.
personal data
SURNAME Zimmer, Bruno H.
ALTERNATIVE NAMES Zimmer, Bruno Hasbrouck
BRIEF DESCRIPTION American chemist
DATE OF BIRTH October 31, 1920
PLACE OF BIRTH Kingston (New York)
DATE OF DEATH November 26, 2005
Place of death La Jolla