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Raheem K, Cassidy J, Betts A, Ryan B. Use of confocal Raman microscopy to characterise ethyl cyanoacrylate adhesive depth curing. Phys Chem Chem Phys 2020; 22:23899-23907. [PMID: 33073814 DOI: 10.1039/d0cp04053c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In situ spatial temporal measurement of monomer conversion during adhesive bondline curing remains a challenging area. The aim of this work was to demonstrate the effectiveness of using confocal Raman microscopy in a specially configured experimental set-up, as a versatile tool for measuring monomer concentration changes as a function of both time and adhesive bond depth during ethyl cyanoacrylate polymerisation. This also allowed monitoring of the extent of polymerisation at the adhesive substrate interface independently of the bulk bondline polymerisation region. Key kinetic parameters such as inhibition time tlag, rate of reaction Rmax and extent of reaction [αt]max were obtained by fitting the experimental data to sigmoidal growth curves using simple piecewise regression models. A systematic characterisation of a polymerisation reaction was conducted using different sample substrate types (copper alloy (red brass), aluminium, aluminium alloy, stainless steel and borosilicate glass) and at various reaction temperatures. Reaction rates were found to decrease further away from the substrate interface in the bulk volume region. The fastest kinetics occurred in the vicinity of nucleophilic hydroxyl rich surfaces such as at the copper alloy (red brass). In addition to substrate surface chemistry, surface roughness was also a factor, with the highest reaction rates occurring with a grit blasted (roughened) aluminium alloy (2024 T3) surface. An approximately linear dependence of the ln Rmaxvs. 1/T (Arrhenius) plot was recorded within the temperature range of 291-328 K. A better fit was obtained however through the use of two separate linear slopes, possibly indicative of a change of polymerisation reaction mechanism taking place at elevated temperatures with two distinct activation energies. Further work conducted using a larger number of temperatures would be useful to verify this finding. This work confirmed that differences in the rates of interfacial and bulk polymerisation processes could be readily measured in situ using confocal Raman microscopy which is a powerful technique for investigating such surface-confined and bulk polymerisation reactions.
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Affiliation(s)
- Kevin Raheem
- Applied Electrochemistry Group, FOCAS Institute, Technological University Dublin, Camden Row, Dublin, Ireland and Chemical and Pharmaceutical Sciences, Technological University Dublin, City Campus, Kevin Street, Dublin, D08NF72, Ireland
| | - John Cassidy
- Applied Electrochemistry Group, FOCAS Institute, Technological University Dublin, Camden Row, Dublin, Ireland and Chemical and Pharmaceutical Sciences, Technological University Dublin, City Campus, Kevin Street, Dublin, D08NF72, Ireland
| | - Anthony Betts
- Applied Electrochemistry Group, FOCAS Institute, Technological University Dublin, Camden Row, Dublin, Ireland and Chemical and Pharmaceutical Sciences, Technological University Dublin, City Campus, Kevin Street, Dublin, D08NF72, Ireland
| | - Bernard Ryan
- Ireland, Henkel, Tallaght Business Park, Whitestown Industrial Estate, Dublin 24, Ireland
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Surface immobilization of thermo-responsive poly(N-isopropylacrylamide) by simple entrapment in a 3-aminopropyltriethoxysilane network. POLYMER 2016; 101:139-150. [DOI: 10.1016/j.polymer.2016.08.059] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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3
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Baesch S, Siebel D, Schmidt-Hansberg B, Eichholz C, Gerst M, Scharfer P, Schabel W. Comparison of Surfactant Distributions in Pressure-Sensitive Adhesive Films Dried from Dispersion under Lab-Scale and Industrial Drying Conditions. ACS APPLIED MATERIALS & INTERFACES 2016; 8:8118-8128. [PMID: 26953641 DOI: 10.1021/acsami.6b00830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Film-forming latex dispersions are an important class of material systems for a variety of applications, for example, pressure-sensitive adhesives, which are used for the manufacturing of adhesive tapes and labels. The mechanisms occurring during drying have been under intense investigations in a number of literature works. Of special interest is the distribution of surfactants during the film formation. However, most of the studies are performed at experimental conditions very different from those usually encountered in industrial processes. This leaves the impact of the drying conditions and the resulting influence on the film properties unclear. In this work, two different 2-ethylhexyl-acrylate (EHA)-based adhesives with varying characteristics regarding glass transition temperature, surfactants, and particle size distribution were investigated on two different substrates. The drying conditions, defined by film temperature and mass transfer in the gas phase, were varied to emulate typical conditions encountered in the laboratory and industrial processes. Extreme conditions equivalent to air temperatures up to 250 °C in a belt dryer and drying rates of 12 g/(m(2)·s) were realized. The surfactant distributions were measured by means of 3D confocal Raman spectroscopy in the dry film. The surfactant distributions were found to differ significantly with drying conditions at moderate film temperatures. At elevated film temperatures the surfactant distributions are independent of the investigated gas side transport coefficients: the heat and mass transfer coefficient. Coating on substrates with significantly different surface energies has a large impact on surfactant concentration gradients, as the equilibrium between surface and bulk concentration changes. Dispersions with higher colloidal stability showed more homogeneous lateral surfactant distributions. These results indicate that the choice of the drying conditions, colloidal stability, and substrates is crucial to control the surfactant distribution. Results obtained under lab-scale drying conditions cannot be transferred directly to the industrial application. The results were similar for both tested adhesive material systems, despite their different properties. This indicates that other properties, such as the particle size distribution and glass transition temperature, have surprisingly little effect on the development of the surfactant distribution.
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Affiliation(s)
- S Baesch
- Institute of Thermal Process Engineering, Karlsruhe Institute of Technology , Kaiserstr. 12, 76131 Karlsruhe, Germany
| | - D Siebel
- Institute of Thermal Process Engineering, Karlsruhe Institute of Technology , Kaiserstr. 12, 76131 Karlsruhe, Germany
| | | | | | | | - P Scharfer
- Institute of Thermal Process Engineering, Karlsruhe Institute of Technology , Kaiserstr. 12, 76131 Karlsruhe, Germany
| | - W Schabel
- Institute of Thermal Process Engineering, Karlsruhe Institute of Technology , Kaiserstr. 12, 76131 Karlsruhe, Germany
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Zhang J, Severtson SJ, Houtman CJ. Characterizing the distribution of sodium alkyl sulfate surfactant homologues in water-based, acrylic pressure-sensitive adhesive films. J Phys Chem B 2011; 115:8138-44. [PMID: 21604743 DOI: 10.1021/jp202731h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The distributions of three sodium alkyl sulfate surfactants in dry adhesive films cast from water-based latexes were characterized using confocal Raman microscopy (CRM) and contact angle (CA) and tack measurements. Sodium dodecyl sulfate (SDS), sodium tetradecyl sulfate (STS), and sodium octadecyl sulfate (SODS) were added to dialyzed commercial adhesive latex at various concentrations. Uneven distributions were found for all three surfactants along with a tendency to enrich film-air interfaces and, to a much lesser extent, film-glass interfaces. SDS demonstrated the greatest tendency to concentrate near film surfaces followed by STS and SODS. For all three surfactants, water CA values for dried films decreased sharply with increasing concentrations in the latex, but significant differences were observed, with SDS again having the greatest impact followed by STS and SODS. Tack of dried polymer films was also found to decrease with increasing latex surfactant levels, with SDS producing the sharpest drop as well as the lowest plateau values. Results indicate that interfacial enrichment by surfactants is detectable via both CRM and CA measurements, and this enrichment can significantly affect the performance of films. Finally, surface enrichment levels are qualitatively related to measures of the surfactants' affinity for aqueous solutions, as characterized by the logarithm of their 1-octanol-water distribution coefficients (K(ow)).
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Affiliation(s)
- Jilin Zhang
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, Minnesota 55108, United States
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5
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Kaewsaneha C, Opaprakasit P, Polpanich D, Smanmoo S, Tangboriboonrat P. Composite Particles of Disinfectant Nanocapsules-Skim Rubber Latex. INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION 2010. [DOI: 10.1080/1023666x.2010.521294] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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6
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Hu L, Zhang C, Chen Y, Hu Y. Synthesis and silicon gradient distribution of emulsifier-free TRIS-containing acrylate copolymer. Colloids Surf A Physicochem Eng Asp 2010. [DOI: 10.1016/j.colsurfa.2010.08.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Arnold C, Thalmann F, Marques C, Marie P, Holl Y. Surfactant Distribution in Waterborne Acrylic Films. 1. Bulk Investigation. J Phys Chem B 2010; 114:9135-47. [DOI: 10.1021/jp103347n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Céline Arnold
- Institut Charles Sadron, CNRS UPR 22, Université de Strasbourg, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
| | - Fabrice Thalmann
- Institut Charles Sadron, CNRS UPR 22, Université de Strasbourg, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
| | - Carlos Marques
- Institut Charles Sadron, CNRS UPR 22, Université de Strasbourg, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
| | - Pascal Marie
- Institut Charles Sadron, CNRS UPR 22, Université de Strasbourg, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
| | - Yves Holl
- Institut Charles Sadron, CNRS UPR 22, Université de Strasbourg, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
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Maiz J, Sacristan J, Mijangos C. Probing the presence and distribution of single-wall carbon nanotubes in polyvinylidene difluoride 1D nanocomposites by confocal Raman spectroscopy. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2009.11.063] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Xu GH, Dong J, Severtson SJ, Houtman CJ, Gwin LE. Modifications of surfactant distributions and surface morphologies in latex films due to moisture exposure. J Phys Chem B 2009; 113:10189-95. [PMID: 19572658 DOI: 10.1021/jp902716b] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Migration of surfactants in water-based, pressure-sensitive adhesive (PSA) films exposed to static and cyclic relative humidity conditions was investigated using confocal Raman microscopy (CRM) and atomic force microscopy (AFM). Studied PSA films contain monomers n-butyl acrylate, vinyl acetate, and methacrylic acid and an equal mass mixture of anionic and nonionic nonylphenol ethoxylate emulsifiers. A leveling of surfactant concentration distributions is observed via CRM after films stored at 50% relative humidity (RH) are exposed to a 100% RH for an extended time period, while relatively small increases in surface enrichment occur when films are stored at 0% RH. Use of CRM for binary mixtures containing anionic or nonionic surfactant and latex that has undergone dialysis to remove nonpolymeric components indicates that surfactant-polymer compatibility governs to a great extent surface enrichment, but not changes observed with humidity variations. AFM images show that upon drying latex coatings, surfactant and other additives collect in large aggregation regions, which protrude from film surfaces. These structures are absent at high humidity, which appears to result from lateral spreading across the polymer surface. When humidity is reduced, aggregation regions reform but appear to be smaller and more evenly dispersed, and by cycling humidity between 0 and 100% RH, interfacial enrichment can be seen to diminish. Presented results provide greater insights into the distribution behavior of surfactants in latex films and potential mechanisms for observed issues arising for these systems.
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Affiliation(s)
- Guizhen H Xu
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, 2004 Folwell Avenue, St. Paul, Minnesota 55108, USA
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10
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Tong Q, Mecking S. Submicron films prepared from aqueous dispersions of nanoscale polymer crystals. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pola.23682] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Qiong Tong
- University of Konstanz, Chair of Chemical Materials Science, Department of Chemistry, Universitätsstr. 10, D‐78457 Konstanz, Germany
| | - Stefan Mecking
- University of Konstanz, Chair of Chemical Materials Science, Department of Chemistry, Universitätsstr. 10, D‐78457 Konstanz, Germany
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Zhang J, Dubay MR, Houtman CJ, Severtson SJ. Sulfonated Amphiphilic Block Copolymers: Synthesis, Self-Assembly in Water, and Application as Stabilizer in Emulsion Polymerization. Macromolecules 2009. [DOI: 10.1021/ma900795f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jiguang Zhang
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, 2004 Folwell Avenue, St. Paul, Minnesota 55108
| | - Matthew R. Dubay
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, 2004 Folwell Avenue, St. Paul, Minnesota 55108
| | - Carl J. Houtman
- USDA, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, Wisconsin 53726
| | - Steven J. Severtson
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, 2004 Folwell Avenue, St. Paul, Minnesota 55108
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12
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Confocal Raman Microspectroscopy: A Non-Invasive Approach for in-Depth Analyses of Polymer Substrates. MACROMOL CHEM PHYS 2009. [DOI: 10.1002/macp.200800582] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Xu GH, Dong J, Zhang J, Severtson SJ, Houtman CJ, Gwin LE. Characterizing the distribution of nonylphenol ethoxylate surfactants in water-based pressure-sensitive adhesive films using atomic-force and confocal Raman microscopy. J Phys Chem B 2008; 112:11907-14. [PMID: 18767777 DOI: 10.1021/jp804876x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Surfactant distributions in model pressure-sensitive adhesive (PSA) films were investigated using atomic force microscopy (AFM) and confocal Raman microscopy (CRM). The PSAs are water-based acrylics synthesized with n-butyl acrylate, vinyl acetate, and methacrylic acid and two commercially available surfactants, disodium (nonylphenoxypolyethoxy)ethyl sulfosuccinate (anionic) and nonylphenoxypoly(ethyleneoxy) ethanol (nonionic). The ratio of these surfactants was varied, while the total surfactant content was held constant. AFM images demonstrate the tendency of anionic surfactant to accumulate at the film surfaces and retard latex particle coalescence. CRM, which was introduced here as a means of providing quantitative depth profiling of surfactant concentration in latex adhesive films, confirms that the anionic surfactant tends to migrate to the film interfaces. This is consistent with its greater water solubility, which causes it to be transported by convective flow during the film coalescence process. The behavior of the nonionic surfactant is consistent with its greater compatibility with the polymer, showing little enrichment at film interfaces and little lateral variability in concentration measurements made via CRM. Surfactant distributions near film interfaces determined via CRM are well fit by an exponential decay model, in which concentrations drop from their highs at interfaces to plateau values in the film bulk. It was observed that decay constants are larger at the film-air interface compared with those obtained at the film-substrate side indicating differences in the mechanism involved. In general, it is shown here that CRM acts as a powerful compliment to AFM in characterizing the distribution of surfactant species in PSA film formation.
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Affiliation(s)
- Guizhen H Xu
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, 2004 Folwell Ave., St. Paul, Minnesota 55108, USA
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14
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Mota M, Yelshin A, Fidaleo M, Flickinger MC. Modelling diffusivity in porous polymeric membranes with an intermediate layer containing microbial cells. Biochem Eng J 2007. [DOI: 10.1016/j.bej.2007.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Ludwig I, Schabel W, Kind M, Castaing JC, Ferlin P. Drying and film formation of industrial waterborne latices. AIChE J 2007. [DOI: 10.1002/aic.11098] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Sanmiguel M, Soto N, Reyes Y, Vázquez F. Pressure-Sensitive Adhesives Based on Nanostructured Latex Particles. INT J POLYM MATER PO 2006. [DOI: 10.1080/00914030500237211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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17
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A depth-resolved look at the network development in alkyd coatings by confocal Raman microspectroscopy. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.10.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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18
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Soto N, Sanmiguel M, Vázquez F. Synthesis and Characterization of Water-Borne Adhesives Based on 2-Ethylhexylacrylate-butylacrylate Copolymers Functionalized with Acrylic Acid. INT J POLYM MATER PO 2005. [DOI: 10.1080/009140390504852] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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19
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Råsmark PJ, Andersson M, Lindgren J, Elvingson C. Differences in binding of a cationic surfactant to cross-linked sodium poly(acrylate) and sodium poly(styrene sulfonate) studied by Raman spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:2761-2765. [PMID: 15779946 DOI: 10.1021/la0468693] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Raman spectroscopy has been used to investigate the structure of gel-surfactant complexes. Cross-linked sodium poly(acrylate) and sodium poly(styrene sulfonate) were immersed in solutions of the cationic surfactant dodecyl trimethylammonium bromide. During the deswelling process, two distinct regions could be observed for both types of gels. Looking at the Raman spectra, however, for the poly(styrene sulfonate), the surfactant could be found throughout the gel particle, whereas for poly(acrylate), essentially all the surfactant was bound in a surface layer.
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Affiliation(s)
- Per Johan Råsmark
- Department of Physical Chemistry, Uppsala University, Box 579, S-751 23 Uppsala, Sweden
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20
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Santos JP, Corpart P, Wong K, Galembeck F. Heterogeneity in styrene-butadiene latex films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:10576-10582. [PMID: 15544387 DOI: 10.1021/la048319a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Low-Tg styrene-butadiene (SB) latex films were investigated by noncontact atomic force microscopy and scanning electric potential microscopy, revealing a number of different morphologies and electric potential patterns across films cast from the same SB latex dispersions under the same conditions. Surface leveling and charge dispersion throughout the films are, thus, restrained even at temperatures above Tg and the minimum film-formation temperature. An unprecedented electric pattern is observed, in which the particle cores are more positive than the contacting particle outer layers. Different packing patterns, including cubic and hexagonal arrays, coexist in neighboring areas. Zonal centrifugation of the SB latex in sucrose density gradient shows that particles cover a broad range of densities. Thus, film surface heterogeneity is at least partly due to particle heterogeneity. Fractal dimensions of topographic profiles are lower than those of the electric potential profiles, showing that charge mobility is much more restrained than polymer chain motion at the film surface and that it imposes a limit to the charged chain-ends motion.
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Affiliation(s)
- Juliane P Santos
- Institute of Chemistry, Universidade Estadual de Campinas, P.O. Box 6154, 13083-970 Campinas SP, Brazil
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Belaroui F, Hirn MP, Grohens Y, Marie P, Holl Y. Distribution of water-soluble and surface-active low-molecular-weight species in acrylic latex films. J Colloid Interface Sci 2003; 261:336-48. [PMID: 16256540 DOI: 10.1016/s0021-9797(03)00098-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2002] [Accepted: 01/16/2003] [Indexed: 10/27/2022]
Abstract
Monodisperse core-shell latices were synthesized, differing in the acrylic acid (AA) content in the particle shell (1 or 4 wt%) and the Tg of the acrylic core (around -40 or 10 degrees C). In a first step, the drying mechanisms of the dialyzed latices were studied by confocal Raman spectroscopy. It was shown that, besides some unexpected features (briefly described in the article), drying occurred in a rather classical way, i.e., simultaneously from top to bottom and from edge to center. Then, the distributions of sulfate ion (SO4) (from sodium sulfate) and sodium dodecyl sulfate (SDS) in the dry latex films were established by confocal Raman spectroscopy and attenuated total reflectance (ATR). The two techniques were complementary. SO4 and SDS distributions were quite different, although presenting some common characteristics. In both cases, repartition of the low-molecular-weight species in the film was even less homogeneous when the AA content was lower and the particle core softer. However, SO4 showed enrichment at the film-substrate interface and depletion at the air side, whereas SDS showed concentration maxima at both interfaces. Interpretations stress the importance of desorption from the particle-water interface, transport by water, size effects, and diffusion.
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Affiliation(s)
- F Belaroui
- Institut de Chimie des Surfaces et Interfaces, CNRS, B.P. 2488, 68057 Mulhouse, France
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Larsson M, Lindgren J, Ljunglöf A, Knuuttila KG. Ligand distributions in agarose particles as determined by confocal Raman spectroscopy and confocal scanning laser microscopy. APPLIED SPECTROSCOPY 2003; 57:251-255. [PMID: 14658615 DOI: 10.1366/000370203321558146] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Confocal Raman spectroscopy and confocal scanning laser microscopy have been used to analyze ligand distributions within individual chromatographic adsorbent particles. Three different types of particles have been investigated. The first type was synthesized to have a uniform distribution of allyl groups, whereas the two others were designed to have a surface layer of sulphopropyl groups and cores containing allyl groups and dextran, respectively. With confocal Raman spectroscopy it was possible to follow the distribution of both the surface layer and the interior. The distribution of sulphopropyl groups was evaluated with both confocal scanning laser microscopy and confocal Raman spectroscopy, whereas the distributions of allyl groups and dextran were evaluated only with the latter method. The results from the confocal measurements showed the expected result with a uniform distribution of allyl groups in the first type of particle and surface layers of sulphopropyl groups and cores with dextran or allyl groups for the two others.
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Affiliation(s)
- Mina Larsson
- Materials Chemistry, The Angstrom Laboratory, Uppsala University, Box 538, Se-751 21 Uppsala, Sweden
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Larsson M, Lindgre J, Ljunglöf A, Knuuttila KG. Confocal Raman and fluorescence spectroscopy applied to polymeric chromatographic adsorbent particles. J Chromatogr A 2002; 954:151-8. [PMID: 12058899 DOI: 10.1016/s0021-9673(02)00181-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Distributions of functional groups in individual chromatographic adsorbent particles have been investigated using confocal Raman and fluorescence spectroscopy. Measurements have been performed with different microscope objectives and it was found that an immersion objective should be used when wet adsorbent particles are analysed. Nd3+ ions have been used as fluorescence probes to evaluate the distribution of chelating and negatively charged functional groups. The fluorescence spectrum from Nd3+ has also been used to obtain information about the coordination of Nd3+ within the adsorbent particles.
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Affiliation(s)
- Mina Larsson
- Uppsala University, The Angström Laboratory, Materials Chemistry, Sweden
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