3D Printing & Coating Materials

Research Descriptions

Coatings Summary

As a graduate student Dr. Velev was a key experimental investigator in the team that discovered the method of “convective assembly” of microparticles in the meniscus of drying water films. The Velev group at NCSU has engineered a convenient and controllable convective assembly apparatus, and used it in the deposition of antireflective, conductive, and functional nanocoatings.

3D Printing Summary

The Velev group has discovered a new class of materials where ultraflexible filaments are assembled from magnetic nanoparticles wetted by liquid and bound by capillarity. The superparamagnetic nanoparticles used as structural units are covered by condensed lipid films, which form nanocapillary liquid bridges between them. These new soft and magnetically responsive structures can be dynamically reconfigured and used in magnetically self-repairing gels and new types of inks for 3D printing.

Current Projects

Layer-by-layer deposition of polyelectrolytes to improve oxygen barrier properties Austin Williams

Soft dendritic colloids as superhydrophobic and anti-icing surface coatings Austin Williams

Fabrication of strong, tough, and transparent polymer composite films with cellulose nanocrystals Seonju Yeo

Coatings based on epoxy/phenolic resins Yosra Kotb

3D printing of magnetically responsive gels Natasha Castellanos and Lilian Okello

Developing homocomposite thixotropic capillary inks for 3D printing Lilian Okello

Previous Projects

Conformation and structuring of polymer molecules in thin films Sabina Islam

3D printing of homocomposite materials Sangchul Roh

3D printing of composite materials incorporating stimuli-responsive microcapsules Seonju Yeo

Representative Publications

Roh, S.; Okello, L. B.; Golbasi, N.; Hankwitz, J. P.; Liu, J. A.-C.; Tracy, J. B.; Velev, O. D. 3D-Printed Silicone Soft Architectures with Programmed Magneto-Capillary Reconfiguration. Advanced Materials Technologies 2019, 1800528.

Roh, S.; Parekh, D.P.; Bharti, B.; Stoyanov, S.D.; Velev, O.D. 3D Printing by multiphase silicone/water capillary inks. Advanced Materials 2017. DOI: 10.1002/adma.201701554.

Bharti, B.; Rutkowski, D.; Han, K.; Kumar, A.U.; Hall, C.K.; Velev, O.D. Capillary Bridging as a Tool for Assembling Discrete Clusters of Patchy Particles. Journal of the American Chemical Society 2016, 138 (45), 14948-14953.

Bharti, B.; Fameau, A.-L.; Rubinstein, M.; Velev, O.D. Nanocapillarity-mediated Magnetic Assembly of Nanoparticles into Ultraflexible Filaments and Reconfigurable Networks. Nat. Mater. 2015. DOI: 10.1038/nmat4364.

Bharti, B.; Fameau, A.-L.; Velev, O. D. Magnetophoretic assembly of flexible nanoparticles/lipid microfilaments. Faraday Discuss. 2015, 181, 437.

Jerrim, L. B.; Velev, O. D. Deposition of coatings from live yeast cells and large particles by “convective-sedimentation” assembly. Langmuir 2009, 25, 5692–5702.

Prevo, B. G.; Hon, E. W.; Velev, O. D. Assembly and characterization of colloid-based antireflective coatings on multicrystalline silicon solar cells. Journal of Materials Chemistry 2007, 17, 791–799.

Kuncicky, D. M.; Naik, R. R.; Velev, O. D. Rapid deposition and long-range alignment of nanocoatings and arrays of electrically conductive wires from tobacco mosaic virus. Small 2006, 2, 1462–1466.

Prevo, B. G.; Fuller, J. C.; Velev, O. D. Rapid deposition of gold nanoparticle films with controlled thickness and structure by convective assembly. Chemistry of Materials 2005, 17, 28–35.

Prevo, B. G.; Velev, O. D. Controlled, rapid deposition of structured coatings from micro- and nanoparticle suspensions. Langmuir 2004, 20, 2099–2107.