Oleksandr MykhaylykDr Oleksandr O. Mykhaylyk

Senior Research Fellow in Crystalization

Room: E83

Tel: +44-(0)114-22-29418

Fax: +44-(0)114-22-29346

email:

 


Biographical Sketch

Dr. Sasha Mykhaylyk obtained his MSc in Physics (optics and spectroscopy) from Taras Shevchenko Kiev State University in 1991 (Diploma with distinction was awarded on graduation). After obtaining a PhD in solid state physics and crystallography from the Institute for Problems of Materials Science (the Ukrainian Academy of Sciences) in 1996, he became a Research Scientist at the same institute where he was later promoted to a Senior Scientist. After holding Royal Society/NATO Fellowship at the University of Cambridge in 2000-2001 he joined the University of Leeds in 2002 as a Research Associate. He moved to the University of Sheffield in 2004 where he was promoted to a Research Fellow in 2011 and Senior Research Fellow in 2017.

Awards

I.N. Frantsevich Prize from the Ukrainian Academy of Sciences (2000)

Research keywords:

X-ray, light and neutron scattering, soft matter, polymer physics, rheology, fats and lipids.

Selected Publications:

Research interests

Scattering methods

Much of my research focuses on the structural analysis of soft matter materials and in particular polymers. We live in a Golden age of Materials Science and Biology, based on a solid underpinning from Chemistry and Physics. One of the keys to this success is recent progress in structural characterization techniques where scattering methods, giving access to structural organization of matter from atomic scales to microns, occupy a dominating role. Experimental data obtained by scattering methods (SAXS, WAXS, XRD, SANS and SLS) provide structural information associated with Fourier space. My research investigates how this information can be transformed into real space, convenient for our understanding. This involves structural modelling, Monte-Carlo simulations and Fourier transformation techniques. An advantage of scattering methods is that they can be used for kinetic studies of materials in-situ in different environments. Therefore, an other aspect of my work is design of dedicated experimental set-ups for studying materials under external impact such as shear flow or extensional flow, temperature or pH changes. I have a continuous interest in fat crystallization, colloids and nanoparticles structure, in particular core-shell systems (examples of my research are nanodiamonds to carbon onions transition, a phase separation of polyurethane confined by a nanosized spherical shell). My current research is on thermo-responsive block-copolymer micelles and vesicles.

Mechano-optical rheologyResearch Oleksandr Mykhaylyk

Rheology is widely recognized as a basic method in processing of polymers, food and cosmetics. In addition, visualization can be used as an effective tool for studying phenomena taking place in fluids. Since soft matter materials subjected to flow often demonstrate a related anisotropy in their refractive index and stress, this causes birefringence visualizing the flow. I have recently developed a new combinatorial technique, shear-induced polarized light imaging (SIPLI), for rheo-optical measurements of polymeric liquids. The SIPLI technique has already been successfully used for studying shear-induced nucleation and crystallization of polyolefins (see the figure), fibrillation in natural silks and flow alignment of block-copolymer self-assembled structures. My present research focuses on further development of SIPLI for in-situ studies of shear-induced phenomena such as stress, orientation and structural transitions taking place in gels, polymers, copolymers, liquid crystals and colloids.

Polymer crystallization

Microstructure of solidified polymers depends on thermo-mechanical process history. In general, processed thermoplastics are composed of two structural morphologies: spherulitic (isotropic) and shish-kebab (anisotropic). Ratio of these morphologies in the end-product controls its mechanical properties and material performance. While spherulitic structure is reasonably understood there is still no a reliable theory for structural formation of shear-induced shish-kebabs. My work is on physical understanding of how the formation of shear-induced morphologies is related to polymer polydispersity, thermodynamics and flow conditions. Based on our research we have proposed a four-stage model for shish-kebab formation including stretching of molecules, nucleation, aggregation and fibrillation.

Teaching Section

Physical Chemistry

Postgraduate Courses Taught

  • Polymer characterisation and Analysis B

Journal articles

Conference proceedings papers

  • Warren NJ, Mykhaylyk OO, Ryan AJ, Doussineau T, Dugourd P, Antoine R, Portale G & Armes SP (2014) Testing vesicles to destruction: SAXS and mass spectrometry studies on block copolymer vesicles prepared via polymerization-induced self-assembly. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 248
  • Warren NJ, Mykhaylyk OO, Mahmood D, Ryan AJ & Armes SP (2014) Bespoke poly(ethylene glycol)-based diblock copolymer nano-objects via polymerization-induced self-assembly. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 248
  • Fielding LA, Mykhaylyk OO, Schmid A, Fowler PW & Armes SP (2014) Visible Mie scattering from hollow silica particles with particulate shells. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 248
  • Cunningham VJ, Ratcliffe LPD, Blanazs A, Warren NJ, Mykhaylyk OO & Armes SP (2014) Thermo-responsive diblock copolymer worm gels with tunable critical gelation temperature. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 248
  • Mykhaylyk OO, Chambon P, Graham RS, Fairclough JPA, Olmsted PD & Ryan AJ (2008) The specific work of flow as a universal parameter to control the formation of shish-kebab morphology in polymers. XVTH INTERNATIONAL CONGRESS ON RHEOLOGY - THE SOCIETY OF RHEOLOGY 80TH ANNUAL MEETING, PTS 1 AND 2, Vol. 1027 (pp 496-+)
  • Mykhaylyk OO, Smith KW, Martin CM & Ryan AJ (2007) Structural models of metastable phases occurring during the crystallization process of saturated/unsaturated triacylglycerols. Journal of Applied Crystallography, Vol. 40(SUPPL. 1)
  • Mykhaylyk OO, Ryan AJ, Tzokova N & Williams N (2007) The application of distance distribution functions to structural analysis of core-shell particles. Journal of Applied Crystallography, Vol. 40(SUPPL. 1)
  • Hamley IW, Castelletto V, Mykhaylyk OO, Klok HA & Rosler A (2004) Biomimetic hierarchical order in PEG-peptide block copolymers. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 227 (pp U518-U518)
  • Rösler A, Klok HA, Nuhn H, Hamley IW, Castelletto V & Mykhaylyk OO (2003) Nanoscale structure of Poly(Ethylene Glycol) hybrid block copolymers containing amphiphilic β-strand peptide sequences. European Cells and Materials, Vol. 6(SUPPL. 1) (pp 101)