Biographical Memoirs Volume 82 (2003) / Chapter Skim
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Paul John Flory
Paul John Flory
Pages 114-141
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From page 115... ...
unexpectecITy of a heart attack on September 8, 1985, at his vacation home on a hilltop in Big Sur, California. The citation of the Nobel award reacts: "For his funciamental achievements, both theoretical en c!
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As he matured Paul worked diligently on developing his physique through activities such as clitch cligging, vigorous swimming, and mountain hiking. He became a strong
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Manchester College in Indiana, graduating in three years and supporting himself by various jobs. It was at Manchester that his interest in science, particularly chemistry, was inspirer!
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STOCKMAYER) (Jommencing in 1934 Flory clealt with most of the major problems in the physical chemistry of polymeric substances, among them the kinetics en cl mechanism of polymerization, molar mass distribution, solution thermodynamics en c!
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From page 119... ...
on the then prevalent collision theory of bimolecular chemical kinetics. Flory, in constructing a straightforward statistical treatment of the distribution problem, took the contrary view that reactivity under given conditions of solvent, temperature, pressure, and concentration is essentially a function only of local structure en c!
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From page 120... ...
During his DuPont years Flory macle another funciamental contribution to the unclerstancling of polymerization reactions. In a paper reviewing the kinetics of olefin polymerization he pointed out the neecl for inclucling the step known as chain transfer, whereby an actively growing chain molecule abstracts an atom from another molecule, transferring the seat of activity en cl encling its growth.
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From page 121... ...
Carothers hacl correctly concluclecl that this state inclicatecl infinite molecular weight, with the chains forming a giant network, but he calculatecl from simple stoichiometry the number average molecular weight as the appropriate signal. In fact, the gel point is fount!
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From page 122... ...
He stucliecl the tensile strength of elastomers in relation to network structural defects, en c! measured viscosities en cl glass temperatures of polymer melts.
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interactions floes not vanish. In a goocl solvent, chain molecuTes experience a net perturbation that increases without limit as the chain is lengthenecI, en cl the numerical relation between molecular weight en cl effective raclius (the rootmean-square radius of gyration measurable by light scatter~ng~ ctev~ates from tne square-root law that must hoIcl for flexible chains if all the interactions couIcl be ignored.
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From page 124... ...
Soon after the viscosity breakthrough Flory with coworkers Manclelkern en cl Scheraga proclucecl a similar treatment of sedimentation velocity in the ultracentrifuge en cl showocl that from both measurements taken together one conic! extract the molecular weight of the polymer.
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From page 125... ...
These are embocliecl in his second book ( 1969) , Statistical Mechanics of Chain Molecules, and appliec!
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In his own worcis: "Although a chain molecule in the bulk state interferes with itself, it has nothing to gain by expanding, for the decrease in interaction with itself wouIcl be compensatecl by increased interference with its neighbors." Many years after he macle this statement, neutron-scattering stucIies at Grenoble en cl {ulich confirmed it. By taking acivantage of the big difference in neutron-scattering cross-sections between cleuterium en c!
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I have great admiration for the course you are pursuing. The opportunities for contributing to the physical chemistry program as you have outlined them are indeed challenging, and I beg permission to weigh them carefully and deliberately in relation to other proposals which I am seriously considering at the present time.
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These early appointments were responsible for the spectacular rise of Stanford's chemistry department from fifteenth position (in 1957) to fifth (in 1964)
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From page 129... ...
The Stanford honeymoon was over en cl Paul was lapsing into his normal state of moderate discontentment about the slow progress that was being macle in the resolution of certain problems, in particular the lack of adequate building facilities for chemistry. In view of Flory's record of changing jobs frequently, Terman took the matter seriously and promised high priority for a new chemistry building.
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Flory's strong commitment to and reputation as a relentless fighter for the human rights of oppresses! scientists abroacl is well known.
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Eastern Europe. He served on various committees concerned with human rights, such as the Committee of Concerned Scientists, en c!
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On another occasion in the early days we hiked with the Florys at Big Sur when they were beginning to fall in love with the area. Eventually Paul bought property there en c!
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Although we never worked in close proximity, he and I kept in fairly close touch by letters or telephone for the rest of his life. I recall particularly several years before his cleath when he took a whole clay out of his busy life to drive me in his Jeep on the Tong trip from Portola Valley to his vacation house on top of a hill in Big Sur.
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on his paper "Thermoclynamics of High Polymer Solutions," en cl in the course of his presentation the power en cl incisiveness of his intellect, qualities that in part account for his preeminence as a scientist, were macle manifest. He hacl an extraordinary capacity to penetrate to the heart of a scientific problem en cl to isolate the essential features of even complex systems, making them amenable to rigorous mathematical analysis.
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From page 135... ...
After being awarclec! the Nobel Prize the tempo of his activities in the cause of human rights increased, en cl he usecl the aciclecl prestige to try to ameliorate the conclition of Soviet scientists who for reasons of conscience hacl run afoul of the authorities.
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while I was chairman bears on this. Having still retained a vivid recollection of the early seminar of his I hacl heard, it came as something of a surprise to learn that Paul did not particularly enjoy teaching in a classroom setting.
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PAUL JOHN FLORYS 137 the core curriculum in chemistry, failer! to responc!
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59:24153. 1941 Molecular size distribution in three dimensional polymers.
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Statistical mechanics of dilute polymer solutions.
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From page 140... ...
98:5733-48. 1984 Molecular theory of liquid crystals.
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