Interfacial viscoelasticity, yielding and creep ringing of globular protein–surfactant mixtures
Protein–surfactant mixtures arise in many industrial and biological systems, and indeed, blood itself is a mixture of serum albumins along with various other surface-active components. Bovine serum albumin (BSA) solutions, and globular proteins in general, exhibit an apparent yield stress in bulk rh...
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| Format: | Article |
| Language: | en_US |
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Royal Society of Chemistry, The
2013
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| Online Access: | http://hdl.handle.net/1721.1/79125 https://orcid.org/0000-0003-1152-1285 https://orcid.org/0000-0001-8323-2779 |
| _version_ | 1826203569551835136 |
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| author | Jaishankar, Aditya Sharma, Vivek McKinley, Gareth H |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Jaishankar, Aditya Sharma, Vivek McKinley, Gareth H |
| author_sort | Jaishankar, Aditya |
| collection | MIT |
| description | Protein–surfactant mixtures arise in many industrial and biological systems, and indeed, blood itself is a mixture of serum albumins along with various other surface-active components. Bovine serum albumin (BSA) solutions, and globular proteins in general, exhibit an apparent yield stress in bulk rheological measurements at surprisingly low concentrations. By contrasting interfacial rheological measurements with corresponding interface-free data obtained using a microfluidic rheometer, we show that the apparent yield stress exhibited by these solutions arises from the presence of a viscoelastic layer formed due to the adsorption of protein molecules at the air–water interface. The coupling between instrument inertia and surface elasticity in a controlled stress device also results in a distinctive damped oscillatory strain response during creep experiments known as“creep ringing”. We show that this response can be exploited to extract the interfacial storage and loss moduli of the protein interface. The interfacial creep response at small strains can be described by a simple second order system, such as the linear Jeffreys model, however the interfacial response rapidly becomes nonlinear beyond strains of order 1%. We use the two complementary techniques of interfacial rheometry and microfluidic rheometry to examine the systematic changes in the surface and bulk material functions for mixtures of a common non-ionic surfactant, polysorbate 80, and BSA. It is observed that the nonlinear viscoelastic properties of the interface are significantly suppressed by the presence of even a relatively small amount of surfactant (c[subscript surf] > 10[superscript −3] wt.%). Preferential interfacial adsorption of the mobile surfactant at these surfactant concentrations results in complete elimination of the bulk apparent yield stress exhibited by surfactant-free BSA solutions. |
| first_indexed | 2024-09-23T12:39:40Z |
| format | Article |
| id | mit-1721.1/79125 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T12:39:40Z |
| publishDate | 2013 |
| publisher | Royal Society of Chemistry, The |
| record_format | dspace |
| spelling | mit-1721.1/791252022-10-05T04:32:30Z Interfacial viscoelasticity, yielding and creep ringing of globular protein–surfactant mixtures Jaishankar, Aditya Sharma, Vivek McKinley, Gareth H Massachusetts Institute of Technology. Department of Mechanical Engineering Massachusetts Institute of Technology. Hatsopoulos Microfluids Laboratory McKinley, Gareth H. Jaishankar, Aditya Sharma, Vivek Protein–surfactant mixtures arise in many industrial and biological systems, and indeed, blood itself is a mixture of serum albumins along with various other surface-active components. Bovine serum albumin (BSA) solutions, and globular proteins in general, exhibit an apparent yield stress in bulk rheological measurements at surprisingly low concentrations. By contrasting interfacial rheological measurements with corresponding interface-free data obtained using a microfluidic rheometer, we show that the apparent yield stress exhibited by these solutions arises from the presence of a viscoelastic layer formed due to the adsorption of protein molecules at the air–water interface. The coupling between instrument inertia and surface elasticity in a controlled stress device also results in a distinctive damped oscillatory strain response during creep experiments known as“creep ringing”. We show that this response can be exploited to extract the interfacial storage and loss moduli of the protein interface. The interfacial creep response at small strains can be described by a simple second order system, such as the linear Jeffreys model, however the interfacial response rapidly becomes nonlinear beyond strains of order 1%. We use the two complementary techniques of interfacial rheometry and microfluidic rheometry to examine the systematic changes in the surface and bulk material functions for mixtures of a common non-ionic surfactant, polysorbate 80, and BSA. It is observed that the nonlinear viscoelastic properties of the interface are significantly suppressed by the presence of even a relatively small amount of surfactant (c[subscript surf] > 10[superscript −3] wt.%). Preferential interfacial adsorption of the mobile surfactant at these surfactant concentrations results in complete elimination of the bulk apparent yield stress exhibited by surfactant-free BSA solutions. Akzo Nobel (Firm) 2013-06-17T15:20:34Z 2013-06-17T15:20:34Z 2011-08 2011-04 Article http://purl.org/eprint/type/JournalArticle 1744-683X 1744-6848 http://hdl.handle.net/1721.1/79125 Jaishankar, Aditya, Vivek Sharma, and Gareth H. McKinley. Interfacial Viscoelasticity, Yielding and Creep Ringing of Globular Protein–surfactant Mixtures. Soft Matter 7(17): 7623. 2011. https://orcid.org/0000-0003-1152-1285 https://orcid.org/0000-0001-8323-2779 en_US http://dx.doi.org/10.1039/c1sm05399j Soft Matter Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf Royal Society of Chemistry, The MIT web domain |
| spellingShingle | Jaishankar, Aditya Sharma, Vivek McKinley, Gareth H Interfacial viscoelasticity, yielding and creep ringing of globular protein–surfactant mixtures |
| title | Interfacial viscoelasticity, yielding and creep ringing of globular protein–surfactant mixtures |
| title_full | Interfacial viscoelasticity, yielding and creep ringing of globular protein–surfactant mixtures |
| title_fullStr | Interfacial viscoelasticity, yielding and creep ringing of globular protein–surfactant mixtures |
| title_full_unstemmed | Interfacial viscoelasticity, yielding and creep ringing of globular protein–surfactant mixtures |
| title_short | Interfacial viscoelasticity, yielding and creep ringing of globular protein–surfactant mixtures |
| title_sort | interfacial viscoelasticity yielding and creep ringing of globular protein surfactant mixtures |
| url | http://hdl.handle.net/1721.1/79125 https://orcid.org/0000-0003-1152-1285 https://orcid.org/0000-0001-8323-2779 |
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