Prof. Srinivasa R. Raghavan
Patrick & Marguerite Sung Professor
Dept. of Chemical & Biomolecular Engineering
University of Maryland, College Park
Office: 1227C Chem-Nuc Building
Phone: (301) 405-8164
Email: sraghava@umd.edu
Bio | CV | Google Scholar
Featured Group Member
Niti has made a key discovery that some surfactants can self-assemble into long chains (called ‘wormlike micelles’) in polar solvents like glycerol. This paper was recently published in Langmuir. Niti has also designed food-grade dispersants for the cleanup of oil spills.
Featured Group Alumna
Kerry defended her Ph.D. in Chemistry in Aug 2018, after which she joined Gelest Inc. in Philadelphia. In her Ph.D. work, she created polymer capsules with ‘emergent‘ properties as a result of internal chemical reactions. Her paper on inflating and exploding capsules was recently published in Langmuir.
What We Do
We create and invent new materials with unusual or exceptional properties. Read an interview with Prof. Raghavan…
The materials we create are usually soft solids or viscous fluids. We try to tailor their mechanical and flow properties. More…
Our specialty is “smart” materials, whose properties can be switched (by light, heat, electricity, etc.). More…
Our inventions often draw inspiration from nature at various length scales (macro, micro, nano). More…
We emphasize simplicity in our work. That is, we try to find simple routes to new materials using cheap ingredients. More…
Our scientific focus is on discovering the rules for molecular self-assembly into various nanoscale structures. More…
Techniques in which we have expertise include rheology, light scattering, and neutron scattering (SANS). More…
Research Areas Connected to the Group
Featured Research Topic: Artificial Cells
The architecture of life is based on cells (microscale containers), which have organelles, i.e., smaller containers inside them. We are trying to mimic this by creating microscale capsules that have smaller capsules inside them. These multicompartment capsules (MCCs) can contain nanoparticles, enzymes, or bacteria in specific inner compartments (see paper in Chemical Science, 2017). We are collaborating with Prof. Bill Bentley (BioE) in this research.
Featured Application: Stopping Bleeding
Stopping blood loss from wounds is crucial during surgeries and on the battlefield. We got into this area when we discovered a ‘hemostatic’ polymer that is able to convert liquid blood into a gel (see above) by a self-assembly mechanism. The same polymer rapidly arrests bleeding from severe injuries in animal models. This technology won the Invention of the Year award at UMD in 2009, and since then has been patented and FDA-approved. Gel-e, Inc., a company run by a former student, is bringing this to the market.
Did you know?
Our lab is credited with the first biomedical device invented at UMCP to receive FDA approval.
Did you know?
We developed the first food-grade dispersant that can be used to disperse oil spills into seawater.
Publications
Recent
1. J. P. Goertz, K. C. DeMella,…I. White, S. R. Raghavan
Responsive capsules enable hermetic encapsulation of contents and their thermally triggered release.
Materials Horizons, 6, 1238 (2019)
2. K. C. DeMella, S. R. Raghavan
Catalyst-loaded capsules that spontaneously inflate and violently eject their core.
Langmuir, 35, 13718 (2019)
3. A. Gargava, S. Ahn, W. E. Bentley, S. R. Raghavan
Rapid electroformation of biopolymer gels in various shapes: A simpler alternative to 3-D printing.
ACS Applied Materials & Interfaces, 11, 37103 (2019)
4. N. R. Agrawal, X. Yue, Y. Feng, S. R. Raghavan
Wormlike micelles in polar organic solvents: Extending self-assembly to sub-zero temperatures.
Langmuir, 35, 12782 (2019)
5. J. Fernandes, N. Agrawal, F. Aljirafi,…S. R. Raghavan
Does the solvent in a dispersant impact the efficiency of crude-oil dispersion?
Langmuir, 35, 16630 (2019)
6. S. Gharazi, B. C. Zarket, K. C. DeMella, S. R. Raghavan
Nature-inspired hydrogels with soft and stiff zones that exhibit a 100-fold difference in elastic modulus.
ACS Appl. Mater. Interfaces, 10, 34664 (2018)
Featured Recent Publication (1)
This paper shows how to endow a capsule with a ‘hermetic’ seal, i.e., one that is perfectly leak-proof. This is done by making the capsule shell out of a wax with a defined melting temperature. Above this temperature, the shell melts and the contents are released in a burst. The ability to hold on to contents for long times and then release them on-demand makes these capsules useful in a variety of applications.
Featured Classic Publication (1)
Gels that absorb a lot of water are used in many products, such as diapers. This paper described a new superabsorbent gel that beat the world record for water-absorption – it could absorb 3000 times its weight in water. The gel could be easily made in the lab and it was also mechanically strong. Since this paper was published, our recipe has been used by numerous researchers around the world.
Featured Recent Publication (2)
Making gels by 3D printing requires an expensive ‘printer’ and special UV-sensitive ‘inks’. This paper shows an alternative way to create 3D gels of the biopolymer alginate. The key is to induce gelation by an electric field, i.e., by a process called ‘electroformation’. It can be easily done in any lab at low cost, and it yields robust gels in precise shapes and patterns. Living cells can be readily embedded in these gels.
Featured Classic Publication (2)
This paper reported the first example of a nanoparticle-based fluid whose viscosity could be significantly transformed by shining light. The fluid was initially a flowing suspension (sol) of clay nanoparticles. When subjected to UV light, molecules in the sol became photolyzed to form acid. The acid induced the nanoparticles to form a 3-D network, and thereby the sol turned into a gel.
Did you know?
More than 20 patents have been filed by UMD’s Office of Technology Commercialization based on inventions from our lab.
Did you know?
Inventions from our lab have been nominated thrice (in 2009, 2014, 2018) for UMD Invention of the Year. We won this award in 2009 for our blood-gelling polymer.