[ { "id": "authors:axkhm-ky829", "collection": "authors", "collection_id": "axkhm-ky829", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190815-085731838", "type": "article", "title": "Spreading of rinsing liquids across a horizontal rotating substrate", "author": [ { "family_name": "Walls", "given_name": "Daniel J.", "orcid": "0000-0002-2744-0722", "clpid": "Walls-D-J" }, { "family_name": "Ylitalo", "given_name": "Andrew S.", "orcid": "0000-0003-4086-3508", "clpid": "Ylitalo-A-S" }, { "family_name": "Mui", "given_name": "David S. L.", "clpid": "Mui-D-S-L" }, { "family_name": "Frostad", "given_name": "John M.", "orcid": "0000-0001-9259-5854", "clpid": "Frostad-J-M" }, { "family_name": "Fuller", "given_name": "Gerald G.", "orcid": "0000-0002-2924-053X", "clpid": "Fuller-G-G" } ], "abstract": "''Rinsing\" liquids and their dynamics are interesting both fundamentally in the interaction of several classic modes of spreading, and industrially in a variety of cleaning applications, such as in the manufacturing of silicon wafers. In this paper, we investigate the time-dependent spreading behavior of a rinsing liquid across a horizontal, rotating substrate; the rinsing liquid is applied to the center of the rotating substrate as an orthogonal impinging jet of constant volumetric flow. We present experimental findings on the azimuthally averaged outer radius of the spreading liquid, in which we observed four distinct growth behaviors in time. We use lubrication theory to explain these phenomena and to define boundaries within the explored parameter space where each was observed. In the absence of rotation, capillarity dominates and the spreading radius grows as t^(4/10). When centrifugal forces dominate the spreading process, several time dependencies of the spreading radius are possible, with lubrication theory predicting exponential growth as well as power laws of t^(3/4) and t^(3/2).", "doi": "10.1103/physrevfluids.4.084102", "issn": "2469-990X", "publisher": "American Physical Society", "publication": "Physical Review Fluids", "publication_date": "2019-08", "series_number": "8", "volume": "4", "issue": "8", "pages": "Art. No. 084102" }, { "id": "authors:my1vv-92w39", "collection": "authors", "collection_id": "my1vv-92w39", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190807-092151671", "type": "article", "title": "Evolution of rivulets during spreading of an impinging water jet on a rotating, precoated substrate", "author": [ { "family_name": "Ylitalo", "given_name": "Andrew S.", "orcid": "0000-0003-4086-3508", "clpid": "Ylitalo-A-S" }, { "family_name": "Walls", "given_name": "Daniel J.", "orcid": "0000-0002-2744-0722", "clpid": "Walls-D-J" }, { "family_name": "Mui", "given_name": "David S. L.", "clpid": "Mui-D-S-L" }, { "family_name": "Frostad", "given_name": "John M.", "orcid": "0000-0001-9259-5854", "clpid": "Frostad-J-M" }, { "family_name": "Fuller", "given_name": "Gerald G.", "orcid": "0000-0002-2924-053X", "clpid": "Fuller-G-G" } ], "abstract": "The spreading of a liquid film across a rotating surface is inherently unstable due to the centrifugal force, which causes the formation of rivulets along the spreading front. This instability produces a rich diversity of spreading patterns and is important to control for the optimization of spin-coating and spin-rinsing of silicon wafers during the fabrication of microelectronics. The present work is an experimental investigation of the evolution of rivulets arising from this instability during the spreading of an impinging water jet across a rotating substrate that is precoated with a thin, aqueous film. To characterize these rivulets, we developed a high-speed imaging apparatus and image-processing software that traces the spreading front over time. We show how the morphology of the spreading front is qualitatively affected by varying the Reynolds number of the impinging jet, the ratio of centrifugal to Coriolis forces, and the type of liquid used to precoat the substrate. For quantitative analysis of rivulets, we measured the \"compactness ratio\" of the spreading front, which quantifies deviation from a circular spreading front. We used the compactness ratio to demonstrate that rivulets are suppressed most strongly at low rotation rates, at high flow rates, and on substrates precoated with water, although with notable exceptions.", "doi": "10.1063/1.5109806", "issn": "1070-6631", "publisher": "American Institute of Physics", "publication": "Physics of Fluids", "publication_date": "2019-08", "series_number": "8", "volume": "31", "issue": "8", "pages": "Art. No. 082104" }, { "id": "authors:tkxj8-8vh74", "collection": "authors", "collection_id": "tkxj8-8vh74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180720-132716832", "type": "article", "title": "Third normal stress difference and component relaxation spectra for bidisperse melts under oscillatory shear", "author": [ { "family_name": "Kornfield", "given_name": "Julia A.", "orcid": "0000-0001-6746-8634", "clpid": "Kornfield-J-A" }, { "family_name": "Fuller", "given_name": "Gerald G.", "orcid": "0000-0002-2924-053X", "clpid": "Fuller-G-G" }, { "family_name": "Pearson", "given_name": "Dale S.", "clpid": "Pearson-D-S" } ], "abstract": "A recently developed rheooptical technique that simultaneously measures infrared dichroism and birefringence is used to study bidisperse, linear polymer melts in an oscillatory shear. The method was used to individually measure the contribution of the high and low molecular weight components to the third normal stress difference. This was accomplished by measuring the infrared dichroism due to deuterium-labeled polymers. Binary blends are prepared from nearly monodisperse pairs of hydrogenated and deuteriated polyisoprenes of molecular weights 53 000 and 370 000 with volume fractions of long polymer, \u03a6_L, of 0.10, 0.20, 0.30, 0.50, and 0.75. The long-chain relaxation in the blends shows the appearance of a peak for compositions with \u03a6_L \u2264 0.50 at approximately the same frequency as a similar peak in the pure short polymer. The response of the short-chain relaxation in the blends shows the appearance of a low-frequency shoulder that becomes surprisingly large as the volume fraction of long chains increases. The results are used to test a modified reptation model that includes constraint release and a short-range orientational coupling between chain segments.", "doi": "10.1021/ma00019a034", "issn": "0024-9297", "publisher": "American Chemical Society", "publication": "Macromolecules", "publication_date": "1991-09-16", "series_number": "19", "volume": "24", "issue": "19", "pages": "5429-5441" }, { "id": "authors:41mp0-8za15", "collection": "authors", "collection_id": "41mp0-8za15", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180720-134054459", "type": "article", "title": "Molecular weight dependence of component dynamics in bidisperse melt rheology", "author": [ { "family_name": "Ylitalo", "given_name": "Caroline M.", "clpid": "Ylitalo-C-M" }, { "family_name": "Kornfield", "given_name": "Julia A.", "orcid": "0000-0001-6746-8634", "clpid": "Kornfield-J-A" }, { "family_name": "Fuller", "given_name": "Gerald G.", "orcid": "0000-0002-2924-053X", "clpid": "Fuller-G-G" }, { "family_name": "Pearson", "given_name": "Dale S.", "clpid": "Pearson-D-S" } ], "abstract": "Simultaneous measurement of infrared dichroism and birefringence is used to study component relaxation in bimodal molecular weight distribution melts. Nearly monodisperse poly(ethylenepropylene) samples of molecular weights 53K, 125K, and 370K, all above the critical molecular weight for entanglement, were used. Results for the step-strain relaxation of each component and of the total sample are presented and discussed for binary blends of 10, 20, 30, 50, and 75% by volume of the higher molecular weight species for three seta of blends: 53K/125K, 53K/370K, and 125K/370K. For each sample, the relaxation dynamics of the blend and of each component depend upon the two polymer relaxation times and the blend composition. Effects of intermolecular orientational coupling interactions were observed, and a coupling strength of 0.45 was measured. The results of these experiments are compared to a reptation-based constraint release model, and a qualitative agreement is found.", "doi": "10.1021/ma00003a019", "issn": "0024-9297", "publisher": "American Chemical Society", "publication": "Macromolecules", "publication_date": "1991-02-04", "series_number": "3", "volume": "24", "issue": "3", "pages": "749-758" }, { "id": "authors:8gf7q-b4m86", "collection": "authors", "collection_id": "8gf7q-b4m86", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200518-072632377", "type": "article", "title": "Stress optical measurement of the third normal stress difference in polymer melts under oscillatory shear", "author": [ { "family_name": "Kornfield", "given_name": "J. A.", "orcid": "0000-0001-6746-8634", "clpid": "Kornfield-J-A" }, { "family_name": "Fuller", "given_name": "G. G.", "orcid": "0000-0002-2924-053X", "clpid": "Fuller-G-G" }, { "family_name": "Pearson", "given_name": "D. S.", "clpid": "Pearson-D-S" } ], "abstract": "Results are reported for the dynamic moduli, G\u2032 and G\u2033, measured mechanically, and the dynamic third normal stress difference, measured optically, of a series bidisperse linear polymer melts under oscillatory shear. Nearly monodisperse hydrogenated polyisoprenes of molecular weights 53000 and 370000 were used to prepare blends with a volume fraction of long polymer, \u03a6_L, of 0.10, 0.20, 0.30, 0.50, and 0.75. The results demonstrate the applicability of birefringence measurements to solve the longstanding problem of measuring the third normal stress difference in oscillatory flow. The relationship between the third normal stress difference and the shear stress observed for these entangled polymer melts is in agreement with a widely predicted constitutive relationship: the relationship between the first normal stress difference and the shear stress is that of a simple fluid, and the second normal stress difference is proportional to the first. These results demonstrate the potential use of 1,3-birefringence to measure the third normal stress difference in oscillatory flow. Further, the general constitutive equation supported by the present results may be used to determine the dynamic moduli from the measured third normal stress difference in small amplitude oscillatory shear. Directions for future research, including the use of birefringence measurements to determine N\u2082/N\u2081 in oscillatory shear, are described.", "doi": "10.1007/bf01332377", "issn": "0035-4511", "publisher": "Springer", "publication": "Rheologica Acta", "publication_date": "1990-03", "series_number": "2", "volume": "29", "issue": "2", "pages": "105-116" }, { "id": "authors:qng4f-g9618", "collection": "authors", "collection_id": "qng4f-g9618", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120719-090211057", "type": "article", "title": "The measurement of velocity gradients in laminar flow by\n homodyne light-scattering spectroscopy", "author": [ { "family_name": "Fuller", "given_name": "G. G.", "orcid": "0000-0002-2924-053X", "clpid": "Fuller-G-G" }, { "family_name": "Rallison", "given_name": "J. M.", "clpid": "Rallison-J-M" }, { "family_name": "Schmidt", "given_name": "R. L.", "clpid": "Schmidt-R-L" }, { "family_name": "Leal", "given_name": "L. G.", "clpid": "Leal-L-G" } ], "abstract": "A technique for measuring velocity gradients in laminar flows by homodyne light\nscattering is presented. A theory which describes the light-scattering spectrum is\nderived that includes the effects of different types of linear flow fields, particle diffusion\nand the intensity profile in the scattering volume. The conditions which must be\nsatisfied in order that the theory describe the experimental situation are outlined and\ncomplementary experiments are performed which both verify the theory and apply\nthe technique. Verification is provided using the flow in a Couette device, and the flow\ndue to single rotating cylinder in a large bath of fluid. The technique is then applied\nto measure the spatial variation of the shear rate in a four-roll mill.", "doi": "10.1017/S0022112080001280", "issn": "0022-1120", "publisher": "Cambridge University Press", "publication": "Journal of Fluid Mechanics", "publication_date": "1980-10", "series_number": "3", "volume": "100", "issue": "3", "pages": "555-575" } ]