iiinova — where your digital self keeps evolving

Ryan Poling-Skutvik @rpslab.bsky.social · 07/10/2026

📑Our most recent paper out today in @pubs.acs.org shows that carbon nanotubes can diffuse >300x faster than expected in viscoelastic fluids. This enhanced diffusion arises from the anisotropy of the rods, enabling fast motion along their axis. pubs.acs.org/aanmf6/artic...

Table of contents figure showing the anisotropic motion of carbon nanotubes compared to the isotropic transport of spherical particles.

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Ryan Poling-Skutvik @rpslab.bsky.social · 29/09/2026

But some samples show bad agreement, which we show is caused by sufficiently low grafting density so that the polymer is no longer a cylinder but a semidilute coil. We map this through a state diagram showing the transition to poor agreement based on polymer structure.

State diagram identifying when our analytical approach fails to get accurate measurements shown in purple. This failure is caused by the polymer adopting a coil conformation rather than following the cylindrical assumption and is set by the density of polymer at the surface through polymer scaling theories.

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Ryan Poling-Skutvik @rpslab.bsky.social · 29/09/2026

We use this model to iteratively fit the grafting density until peak shifts in different solvents agree with the shifts observed for a bare particle. We achieve convergence to a unique value of grafting density, which agrees quantitatively with TGA irrespective of polymer Mw or nanoparticle size.

Consistent shift in peak position as a function of effective local index once the correct grafting density has been determined.

Correlation between grafting density measured through UV-vis and TGA measurements for different molecular weights and particle sizes (small in light, big in dark)

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Ryan Poling-Skutvik @rpslab.bsky.social · 29/09/2026

Our UV-vis approach recognizes that the polymer shifts the peak of the particle based on local index of refraction. We therefore create a model of polymer conformations at a particle surface to analytically estimate the effective local index.

Schematic of our analytical model. Polymers are approximated as cylinders with radius b piercing through differential shells around a nanoparticle. The transition in polymer conformation to a coil structure is set by the critical radius Rc.

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Ryan Poling-Skutvik @rpslab.bsky.social · 29/09/2026

🧵Need to measure the grafting density of polymer on a nanoparticle? Recent work in ACS Nano @pubs.acs.org from our group identifies a new method based on simple UV-vis experiments. Our approach uses ~1000x less material, is nondestructive, and does not need to know Mw. pubs.acs.org/ancac3/artic...

Overview of the work showing correlation between our new UV-vis approach to quantify grafting density against the current state-of-the-art thermal gravimetric analysis. The correlation holds across polymer size, particle size, and grafting densities.

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Ryan Poling-Skutvik @rpslab.bsky.social · 17/05/2026

Summer has finally hit New England

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Ryan Poling-Skutvik @rpslab.bsky.social · 09/03/2026

Working on a proposal today like...

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Ryan Poling-Skutvik @rpslab.bsky.social · 10/11/2025

I have the great privilege to return to my alma mater @cooperunion.bsky.social to give a seminar today. It’s been over a decade since I was last on campus and it still brings back so many memories. I’m going to be discussing our work on biomaterials and soft matter physics.

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Ryan Poling-Skutvik @rpslab.bsky.social · 14/09/2025

RPS Lab celebrating the start of the year watching the Rhode Island Football Club

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Ryan Poling-Skutvik @rpslab.bsky.social · 01/08/2025

Celebrating our lab's newest graduate, Kylie Hartley, who passed her Masters defense last Friday! 🥳🎓🍺 She has been an incredibly productive student in her time in our group working on developing polymer-based anodes for microbial fuel cells, and we are so proud of her current and future success!

RPS Lab members celebrating masters defense

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Ryan Poling-Skutvik @rpslab.bsky.social · 20/07/2025

A study in contrasts from Arizona to New Hampshire

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Ryan Poling-Skutvik @rpslab.bsky.social · 24/05/2025

In the spirit of @sorheology.bsky.social and “Everything Flows”, look at these beautiful “streamlines” of shale around a rock. Taken at Watkins Glen State Park

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Ryan Poling-Skutvik @rpslab.bsky.social · 23/05/2025

Surprisingly, this collapse is independent of material composition and structure. Furthermore, the position of this peak can be predicted by a combination of linear metrics of viscoelasticity and flow viscosity.

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Ryan Poling-Skutvik @rpslab.bsky.social · 23/05/2025

Specifically, yielding is typically associated with a peak in the loss modulus G”, the height of which is solely a function of tan(delta) in the linear regime. Our finding indicates that the same physics controlling linear viscoelasticity also controls the magnitude of yielding.

Collapse of the peak height in the loss modulus of soft materials during yielding as a function of the loss tangent.

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Ryan Poling-Skutvik @rpslab.bsky.social · 03/05/2025

As a @cooperunion.bsky.social alum, I am shocked (and proud) to only just learn that Cooper was integral to the founding of the Society of Women Engineers

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Ryan Poling-Skutvik @rpslab.bsky.social · 29/04/2025

Been a long time but we’re back for some upgraded x-rays!

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Ryan Poling-Skutvik @rpslab.bsky.social · 26/03/2025

Welp. It happened. Our NIH training grant was terminated on Friday. Just highlighting this incredibly derisive language used in our termination notice. To focus on the positives, see some of the great things our undergraduates have done over the last couple of years: web.uri.edu/esteemed/

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Ryan Poling-Skutvik @rpslab.bsky.social · 17/03/2025

Not a bad morning walk to @apsphysics.bsky.social ! Stop by the @apsdsoft.bsky.social table near Hilton Huntington B/C to say hi!

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Ryan Poling-Skutvik @rpslab.bsky.social · 13/03/2025

Visiting @ucdavisengineering.bsky.social for the day! Looking forward to some good science discussions. Thanks to Tonya Kuhl and the rest of the CHE department for the seminar invitation.

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Ryan Poling-Skutvik @rpslab.bsky.social · 07/03/2025

Fantastic day at New England Complex Fluids. Great talks all around including the first presentations by a couple RPS Lab Members: Undergrad Liam Kennings discussed conductive liquid crystal elastomers and first year PhD candidate Sepehr Yari presented on faster-than-expected SWCNT dynamics

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Ryan Poling-Skutvik @rpslab.bsky.social · 18/01/2025

My preparation for the semester starting next week

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Ryan Poling-Skutvik @rpslab.bsky.social · 14/01/2025

Another summer research opportunity! We have multiple summer programs designed at giving undergraduate students hands-on research experience on Navy-related projects. Summer housing and $6,000 stipend provided. Dates: May 27 - August 1, 2025 Application: bit.ly/4gp1MWl Deadline: Feb. 14, 2025

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Ryan Poling-Skutvik @rpslab.bsky.social · 10/12/2024

Last week, I got the special opportunity to connect four generations of my academic family tree together! Weitz + Lewis --> Conrad @jcconrad.bsky.social --> RPS --> Daniel Keane and RPS lab members IMO, it's one of the best parts of the job to see our impact on new generations of students

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Ryan Poling-Skutvik @rpslab.bsky.social · 06/12/2024

Beautiful Providence morning on my way to the 100(+1)th New England Complex Fluids Symposium

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Ryan Poling-Skutvik @rpslab.bsky.social · 06/12/2024

Congratulations to DOCTOR Daniel Keane for his successful PhD defense!! 🎉👨‍🎓 Today was a big milestone for the RPS Lab today: our first PhD graduate! Danny was our first student and really set an incredible standard for everyone in our group. I am beyond proud of him.

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Ryan Poling-Skutvik @rpslab.bsky.social · 24/11/2024

Our fall/winter lab outing - bowling night!

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Ryan Poling-Skutvik @rpslab.bsky.social · 18/11/2024

Know an undergraduate interested in tackling plastic waste and its impact on the environment? Our URI Plastics REU is open for applications! Earn up to $7,000 for a 10-week research course with housing provided (and maybe enjoy some RI seafood and beaches!) Learn more at web.uri.edu/plastics-reu/

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