micro- and nanostructured polymers, sustainable materials for 3D printing, methods for quantitative atomic force microscopy (Hubert Gojzewski)
The development of new experimental approaches to study heterogeneous polymer systems (HPS), i.e. materials for which two (or more) different phases can be distinguished and one is a polymer, is at the heart of Dr. Eng. Gojzewski work. His goal is to study and better understand the nanoscale structure–property relationships of HPS by sophisticated Atomic Force Microscopy (AFM) methods and its modifications.
Novel characterization at the nanoscale is not the sole goal of Dr. Eng. research programme [1, 2]. Most of the works published were either associated with the synthesis or fabrication of new materials [3-5] or deliberately related to well-known and commonly used materials [6, 7] to obtain relevant practical knowledge about them that was a previous gap in the literature. Other research topics cover, for instance, manufacturing of polymeric materials with controlled or dedicated properties [8, 9].
Currently, Dr. Eng. Gojzewski is challenging the aspects (problems) of polymer additive manufacturing (3D printing). For instance, in a new article, he and co-workers described and addressed the mechanism of the interfacial weakness (in the layer-to-layer area) by quantitative AFM characterization of vat 3D printed photopolymer model samples . The AFM measurements indicated that the thickness of the interfacial area (R1 + R3) can reach as high as 22% of the total (programmed) layer thickness, with Young's modulus dropping by up to 30% (Figure 1). These are substantial values. Therefore, the new knowledge provided in this article will contribute to the further development of 3D printing technology.
Figure 1. Optical and quantitative AFM imaging of the fractured photopolymer obtained by 3D printing. The imaging was performed within the area of, and between, two consecutive printed layers, each 50 µm thick.
The follow-up of the 3D printing project will focus on photopolymers containing fillers from natural sources (cellulose, lignin, and their derivatives). Explaining the impact of structural diversity on the local and bulk properties of 3D printed composites is essential to support the designed objects of a dedicated applicability.
 H. Gojzewski, J. Obszarska, A. Harlay, M.A. Hempenius, G.J. Vancso, Designer poly(urea-siloxane) microspheres with controlled modulus and size: Synthesis, morphology, and nanoscale stiffness by AFM, Polymer 150 (2018) 289-300.
 L. Grebíková, H. Gojzewski, B.D. Kieviet, M. Klein Gunnewiek, G.J. Vancso, Pulling angle-dependent force microscopy, Rev. Sci. Instrum. 88(3) (2017) 033705.
 H. Gojzewski, B. Imre, C. Check, R. Chartoff, G.J. Vancso, Mechanical mapping and morphology across the length scales unveil structure–property relationships in polycaprolactone based polyurethanes, J. Polym. Sci. B 54(22) (2016) 2298-2310.
 E. Maaskant, H. Gojzewski, M.A. Hempenius, G.J. Vancso, N.E. Benes, Thin cyclomatrix polyphosphazene films: Interfacial polymerization of hexachlorocyclotriphosphazene with aromatic biphenols, Polym. Chem. 9(22) (2018) 3169-3180.
 B. Imre, H. Gojzewski, C. Check, R. Chartoff, G.J. Vancso, Properties and Phase Structure of Polycaprolactone-Based Segmented Polyurethanes with Varying Hard and Soft Segments: Effects of Processing Conditions, Macromol. Chem. Phys. 219 (2018) 1700214.
 H. Gojzewski, M. Kappl, A. Ptak, Effect of the Chain Length and Temperature on the Adhesive Properties of Alkanethiol Self-Assembled Monolayers, Langmuir 33 (2017) 11862–11868.
 V. Drebezghova, H. Gojzewski, A. Allal, M.A. Hempenius, C. Nardin, G.J. Vancso, Network mesh nanostructures in cross-linked poly(dimethylsiloxane) visualized by AFM, Macromol. Chem. Phys. 221 (2020) 2000170.
 M. Sadej, H. Gojzewski, P. Gajewski, G.J. Vancso, E. Andrzejewska, Photocurable acrylate-based composites with enhanced thermal conductivity containing boron and silicon nitrides, Express Polym. Lett. 12(9) (2018) 790-807.
 H. Gojzewski, M. Sadej, E. Andrzejewska, M. Kokowska, Nanoscale Young’s modulus and surface morphology in photocurable polyacrylate/nanosilica composites, Eur. Polym. J. 88 (2017) 205-220.
 H. Gojzewski, Z. Guo, W. Grzelachowska, M.G. Ridwan, M.A. Hempenius, D.W. Grijpma, G.J. Vancso, Layer-by-Layer Printing of Photopolymers in 3D: How Weak is the Interface?, ACS Appl. Mater. Interfaces 12(7) (2020) 8908-8914.