176
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Prucker O, Naumann CA, Rühe J, Knoll W, Frank CW. Photochemical Attachment of Polymer Films to Solid Surfaces via Monolayers of Benzophenone Derivatives. J Am Chem Soc 1999. [DOI: 10.1021/ja990962+] [Citation(s) in RCA: 345] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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177
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Heise A, Hedrick JL, Frank CW, Miller RD. Starlike Block Copolymers with Amphiphilic Arms as Models for Unimolecular Micelles. J Am Chem Soc 1999. [DOI: 10.1021/ja984456g] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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178
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Mazzola LT, Frank CW, Fodor SP, Mosher C, Lartius R, Henderson E. Discrimination of DNA hybridization using chemical force microscopy. Biophys J 1999; 76:2922-33. [PMID: 10354420 PMCID: PMC1300264 DOI: 10.1016/s0006-3495(99)77447-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Atomic force microscopy (AFM) can be used to probe the mechanics of molecular recognition between surfaces. In the application known as "chemical force" microscopy (CFM), a chemically modified AFM tip probes a surface through chemical recognition. When modified with a biological ligand or receptor, the AFM tip can discriminate between its biological binding partner and other molecules on a heterogeneous substrate. The strength of the interaction between the modified tip and the substrate is governed by the molecular affinity. We have used CFM to probe the interactions between short segments of single-strand DNA (oligonucleotides). First, a latex microparticle was modified with the sequence 3'-CAGTTCTACGATGGCAAGTC and epoxied to a standard AFM cantilever. This DNA-modified probe was then used to scan substrates containing the complementary sequence 5'-GTCAAGATGCTACCGTTCAG. These substrates consisted of micron-scale, patterned arrays of one or more distinct oligonucleotides. A strong friction interaction was measured between the modified tip and both elements of surface-bound DNA. Complementary oligonucleotides exhibited a stronger friction than the noncomplementary sequences within the patterned array. The friction force correlated with the measured strength of adhesion (rupture force) for the tip- and array-bound oligonucleotides. This result is consistent with the formation of a greater number of hydrogen bonds for the complementary sequence, suggesting that the friction arises from a sequence-specific interaction (hybridization) of the tip and surface DNA.
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179
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Kampf JP, Frank CW, Malmström EE, Hawker CJ. Adaptation of bulk constitutive equations to insoluble monolayer collapse at the air-water interface. Science 1999; 283:1730-3. [PMID: 10073937 DOI: 10.1126/science.283.5408.1730] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A constitutive equation based on stress-strain models of bulk solids was adapted to relate the surface pressure, compression rate, and temperature of an insoluble monolayer of monodendrons during collapse at the air-water interface. A power law relation between compression rate and surface pressure and an Arrhenius temperature dependence of the steady-state creep rate were observed in data from compression rate and creep experiments in the collapse region. These relations were combined into a single constitutive equation to calculate the temperature dependence of the collapse pressure with a maximum error of 5 percent for temperatures ranging from 10 degrees to 25 degrees C.
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180
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Heise A, Hedrick JL, Trollsås M, Miller RD, Frank CW. Novel Starlike Poly(methyl methacrylate)s by Controlled Dendritic Free Radical Initiation. Macromolecules 1998. [DOI: 10.1021/ma980924v] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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181
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Prucker O, Christian S, Bock H, Rühe J, Frank CW, Knoll W. On the glass transition in ultrathin polymer films of different molecular architecture. MACROMOL CHEM PHYS 1998. [DOI: 10.1002/(sici)1521-3935(19980701)199:7<1435::aid-macp1435>3.0.co;2-#] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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182
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Hawker CJ, Malmström EE, Frank CW, Kampf JP. Exact Linear Analogs of Dendritic Polyether Macromolecules: Design, Synthesis, and Unique Properties. J Am Chem Soc 1997. [DOI: 10.1021/ja972027x] [Citation(s) in RCA: 186] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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183
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Frank CW, Rao V, Despotopoulou MM, Pease RFW, Hinsberg WD, Miller RD, Rabolt JF. Structure in Thin and Ultrathin Spin-Cast Polymer Films. Science 1996; 273:912-5. [PMID: 8688068 DOI: 10.1126/science.273.5277.912] [Citation(s) in RCA: 424] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The molecular organization in ultrathin polymer films (thicknesses less than 1000 angstroms) and thin polymer films (thicknesses between 1000 and 10,000 angstroms) may differ substantially from that of bulk polymers, which can lead to important differences in resulting thermophysical properties. Such constrained geometry films have been fabricated from amorphous poly(3-methyl-4-hydroxy styrene) (PMHS) and semicrystalline poly(di-n-hexyl silane) (PD6S) by means of spin-casting. The residual solvent content is substantially greater in ultrathin PMHS films, which suggests a higher glass transition temperature that results from a stronger hydrogen-bonded network as compared with that in thicker films. Crystallization of PD6S is substantially hindered in ultrathin films, in which a critical thickness of 150 angstroms is needed for crystalline morphology to exist and in which the rate of crystallization is initially slow but increases rapidly as the film approaches 500 angstroms in thickness.
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184
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Leezenberg PB, Marcus AH, Frank CW, Fayer MD. Rotational Dynamics of Naphthalene-Labeled Cross-link Junctions in Poly(dimethylsiloxane) Elastomers. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp953632u] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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185
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Friedenberg MC, Fuller GG, Frank CW, Robertson CR. In Situ Optical Studies of Flow-Induced Orientation in a Two-Dimensional Polymer Solution. Macromolecules 1996. [DOI: 10.1021/ma9507812] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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186
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Hoffmann DA, Anderson JE, Frank CW. Solvent partitioning in fluorescent polydimethylsiloxane networks. ACTA ACUST UNITED AC 1995. [DOI: 10.1039/jm9950500013] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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187
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Izumi T, Hirata M, Kokufuta E, Cha HJ, Frank CW. Spectroscopic Studies on the Complexation of Papain with Potassium Poly(Vinyl Alcohol Sulfate). JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 1994. [DOI: 10.1080/10601329409349715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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188
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Frank CW. Support for Russian Science. Science 1993; 262:975. [PMID: 17782034 DOI: 10.1126/science.262.5136.975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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189
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Reichmanis E, Frank CW, O'Donnell JH, Hill DJT. Radiation Effects on Polymeric Materials. ACS SYMPOSIUM SERIES 1993. [DOI: 10.1021/bk-1993-0527.ch001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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190
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Uchino SI, Frank CW. Mechanistic study on chemically amplified resist systems using pinacol rearrangement in phenolic resin. POLYM ENG SCI 1992. [DOI: 10.1002/pen.760322015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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191
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Kosbar LL, Frank CW. The influence of solvent on labelled and free pyrene aggregation in novolac solutions and films. POLYMER 1992. [DOI: 10.1016/0032-3861(92)90574-g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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192
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Yeung AS, Frank CW. Block copolymer micelle solutions: 1. Concentration dependence of polystyrene-poly(ethylene propylene) in heptane. POLYMER 1990. [DOI: 10.1016/0032-3861(90)90081-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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193
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Yeung AS, Frank CW, Singler RE. Excimer fluorescence in polyphosphazenes: 1. Cyclic trimer and polymer solutions. POLYMER 1990. [DOI: 10.1016/0032-3861(90)90257-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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194
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Wachsman ED, Frank CW. Effect of cure history on the morphology of polyimide: Fluorescence spectroscopy as a method for determining the degree of cure. POLYMER 1988. [DOI: 10.1016/0032-3861(88)90043-2] [Citation(s) in RCA: 96] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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195
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Oyama HT, Frank CW. Structure of the polyion complex between poly(sodium P-styrene sulfonate) and poly(diallyl dimethyl ammonium chloride). ACTA ACUST UNITED AC 1986. [DOI: 10.1002/polb.1986.090240816] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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196
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Kolbow D, Hikichi H, Tuthill C, Frank CW, Wiersma GB, Crockett AB, Schonbrod RD. Kinetic Analysis: Benzo(a) pyrene in Southeastern Ohio. ENVIRONMENTAL MONITORING AND ASSESSMENT 1986; 6:231-257. [PMID: 24254734 DOI: 10.1007/bf00396792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/1984] [Indexed: 06/02/2023]
Abstract
Kinetic Analysis has been successful for metallic elements in relatively isolated areas. In this study it is applied to a complex organic compound in a geographical area with a large urban component. Ten media compartments are included, with man as the ultimate receptor. Field data were collected for only 6 of the media and were not used in the analysis but were compared to the calculated steady state concentrations. The greatest differences between calculated and observed values were 4.8-fold for soil and 5.4-fold for sediment. The field sampling regime for soils was biased towards areas of industrialization and probably explains the higher observed value. The lower observed value for sediment is likely due to unknown variables necessary for the estimation of the compartment size and/or the associated transfer rate constants. This study indicated that the Kinetic Analysis technique can be applied successfully to the pre-sampling estimation of the distribution of organic pollutants in environmental systems.
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197
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Semerak SN, Frank CW. Energy migration in the aromatic vinyl polymers. 5. Poly(2-vinyl naphthalene) and polystyrene. CAN J CHEM 1985. [DOI: 10.1139/v85-225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Electronic energy migration in pure poly(2-vinyl naphthalene) (P2VN) is analyzed in terms of a theory for three-dimensional transport and trapping in a homogeneous system of randomly distributed chromophores. A simpler theory for 3-D transport on a spatially periodic lattice, which was applied previously to polystyrene (PS) gave self-contradictory results for P2VN because of higher transport rates in P2VN. The fraction of rings in excimer-forming sites (EFS) in pure P2VN, analyzed by the former theory, is found to be 0.072 – moderately larger than the single-chain fraction of 0.026. In contrast, the EFS ring fraction in pure PS was 0.33, much larger than the single-chain fraction of 0.051. This reflects the reduced probability, relative to a phenyl ring pair, of packing a naphthyl ring pair into the necessary sandwich arrangement in the pure polymers. Energy migration in very dilute, miscible blends containing P2VN is analyzed by a one-dimensional transport model, which was applied previously to similar blends containing PS. The nearest-neighbor migration rates obtained from the data for both P2VN and PS are about one hundred times higher than the expected dipole–dipole rates. This suggests that (1) migration is not limited to nearest-neighbor rings, (2) the morphology of the dilute blends does not consist of isolated chains of the aromatic vinyl polymers, or (3) short-range electronic interactions other than dipole–dipole are involved in energy migration.
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198
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Fredrickson GH, Andersen HC, Frank CW. Macromolecular pair correlation functions from fluorescence depolarization experiments. ACTA ACUST UNITED AC 1985. [DOI: 10.1002/pol.1985.180230314] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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199
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Wiersma GB, Frank CW, Case MJ, Crockett AB. The use of simple kinetic models to help design environmental monitoring systems. ENVIRONMENTAL MONITORING AND ASSESSMENT 1984; 4:233-255. [PMID: 24257780 DOI: 10.1007/bf00394143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This paper describes the application of simple linear models to help design environmental monitoring systems. This process involves five steps: (1) The derivation of a schematic of the identified pollutant's transport and fate. (2) The derivation of the equation in the schematic. (3) Estimation of input data and numerical solution. (4) Comparison with initial field data. (5) Design of a monitoring system.Two examples of how this system was applied under field conditions are given. Advantages of this approach are: (1) It forces a consideration of the system as a whole rather than a series of distinct environmental components. (2) It forces a consideration of the physical-chemical and biological factors effecting pollutant transport in the system. (3) It sets up an analytical procedure for data analysis at the time the monitoring system is designed. (4) It helps show the functional relationship between pollutant levels in different environmental media. (5) It identifies points where sampling design could be changed to provide for a more efficient monitoring system. (6) It identifies gaps in our knowledge base.
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200
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Abstract
Mercury levels in blood and in mouth air before and after chewing were measured in 47 persons with and 14 persons without dental amalgam restorations. Questionnaires relating to exogenous sources of mercury exposure were administered to both groups. Differences in the mouth air mercury levels before and after chewing were statistically significant in the group with amalgams, but not in the group without amalgams. Analysis of the data from the questionnaires indicated that little or no exogenous exposure to mercury occurred among the two groups. Blood mercury concentrations were positively correlated with the number and surface area of amalgam restorations and were significantly lower in the group without dental amalgams.
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