Using Optical Tweezers for the Characterization of Polyelectrolyte Solutions with Very Low Viscoelasticity

Pommella, Angelo; Preziosi, Valentina; Caserta, Sergio; Cooper, Jonathan M.; Guido, Stefano; Tassieri, Manlio

doi:10.1021/la4015948

Cited by 33 publications

(24 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A common task of microrheology studies is to correlate the time-dependent 35 trajectories of the tracer particles to the frequency-dependent linear viscoelastic (LVE) properties of the suspending fluid. In the specific case of OT, methods for performing linear microrheology measurements of complex fluids have been presented [43,44,52] and validated [52,53,27,54] against conventional bulk rheology methods. However, in literature there exist some 'peaks & troughs' 40 (not to mention inconsistencies) on the modus operandi of microrheology measurements performed with OT that I wish to address and possibly 'iron out' avoiding future potentially misleading outcomes.…”

Section: Introductionmentioning

confidence: 99%

Microrheology with optical tweezers: peaks & troughs

Tassieri

2019

Current Opinion in Colloid & Interface Science

Self Cite

View full text Add to dashboard Cite

Since their first appearance in the '70s, Optical Tweezers have been successfully exploited for a variety of applications throughout the natural sciences, revolutionising the field of micro-sensing. However, when adopted for microrheology studies, there exist some peaks & troughs on their modus operandi and data analysis that I wish to address and possibly iron out, providing a guide to future rheological studies from a microscopic perspective.

show abstract

Section: Introductionmentioning

confidence: 99%

Microrheology with optical tweezers: peaks & troughs

Tassieri

2019

Current Opinion in Colloid & Interface Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…A signal is said to be oversampled by a factor of β ≡ f s /(2B). 12 Driven by the same aim, Nishi et al resembling the mean-square-displacement of a weakly trapped probe particle suspended into a non-Newtonian fluid (similar to those often seen in optical tweezers experiments 5,[13][14][15][16][17] ):…”

Section: File Moreover As a Mean Of Comparison I Employ The Analytmentioning

confidence: 95%

Comment on “A symmetrical method to obtain shear moduli from microrheology” by K. Nishi, M. L. Kilfoil, C. F. Schmidt, and F. C. MacKintosh, Soft Matter, 2018, 14, 3716

Tassieri

2018

Soft Matter

Self Cite

View full text Add to dashboard Cite

show abstract

“…Note that the optical tweezer has been widely applied in the microrheological measurements of soft matters including polymer solutions, colloidal dispersions, gels, and biological materials . However, it has some inherent problems.…”

Section: Active Microrheologymentioning

confidence: 99%

“…For a fluid with a small Reynolds number, the first term in Equation (10) is dropped. The amplitude A of the displacement and the phase shift δ between the sinusoidal stress and displacement of the particle could be given by Note that the optical tweezer has been widely applied in the microrheological measurements of soft matters including polymer solutions, [67,68] colloidal dispersions, [69,70] gels, [71,72] and biological materials. [73][74][75] However, it has some inherent problems.…”

Section: Optical Tweezersmentioning

confidence: 99%

Rheological Study of Soft Matters: A Review of Microrheology and Microrheometers

Liu

2017

Macro Chemistry & Physics

View full text Add to dashboard Cite

To overcome these shortcomings of macrorheology, a number of novel microrheological methods have emerged during the last few decades, [2] often involving a small tracking or probing particle (micrometer size) dispersed in a softmatter medium. By tracking the fluctuation due to thermal energy or applying an external force, usually in the form of magnetic force or optical trap, one can measure local mechanical responses. The local disturbance in a micrometer scale avoids reconstruction of local viscoelastic response, an inevitable problem in bulk rheology, especially when the probe particle size is smaller than the characteristic length of a soft matter. Depending on whether the probe is manipulated by an external force instead of a random walk due to thermal fluctuation, microrheometers can be generally characterized as active or passive ones. For an equilibrium system, the fluctuationdissipation theorem (FDT) guarantees that these two methods are equivalent. [3] In this review, we will detail these two classes of microrheometers, including their basic principles and typical setups as well as some recently developed hybrid microrheometers, [4][5][6] often used in characterizing polymer solutions and biological materials. Passive MicrorheologyIn a passive microrheometry method, the fluctuation of probes dispersed in a soft-matter medium is detected and analyzed by calculating the mean-square displacement (MSD) often from their video-based trajectories or scattered light intensities. Since the fluctuation of probes in space is driven by an extremely small thermal energy (k B T), the results from a passive method are always fallen inside the linear range of viscoelasticity. Generally, the elastic modulus is estimated within an upper limit of hundreds of Pa, which means that passive microrheometers are more suitable for measuring "soft" materials with a low viscosity and elasticity. Otherwise, the probes would be trapped without a measurable movement. Even newly developed super-resolution microscopes can provide a sub-nanometer resolution, [7] they are still not widely available methods and have a limited frequency range (up to 100 Hz). Mechanical properties of a soft matter can be obtained from MSD by using the generalized Stokes-Einstein relation (GSER). [8,9] In two extreme cases, (1) the probe is dispersed in a Newtonian viscous fluid and undergoes a Brownian motion with an MSD of 〈Δr 2 (t)〉. The viscosity η is related to the translational diffusion coefficient D as Microrheological TechniquesRheological properties of soft matter like polymer solutions/gels, colloidal dispersions, and biological materials have been extensively studied by macroscopic methods. Recently, a set of microrheometers has emerged as powerful tools to investigate the dynamics and structures of homogeneous or heterogeneous soft matter at the micro-or nanoscale. In this review, these microrheometers, including some novel hybrid microrheometers are summarized and compared.

show abstract

Using Optical Tweezers for the Characterization of Polyelectrolyte Solutions with Very Low Viscoelasticity

Cited by 33 publications

References 48 publications

Microrheology with optical tweezers: peaks & troughs

Microrheology with optical tweezers: peaks & troughs

Comment on “A symmetrical method to obtain shear moduli from microrheology” by K. Nishi, M. L. Kilfoil, C. F. Schmidt, and F. C. MacKintosh, Soft Matter, 2018, 14, 3716

Rheological Study of Soft Matters: A Review of Microrheology and Microrheometers

Contact Info

Product

Resources

About