Browsing by Author "Houbenov, Nikolay"
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- Cellulose-glycopolymer based systems as a promising platform for supramolecular gel design
Perustieteiden korkeakoulu | Bachelor's thesis(2015-07-07) Douhaniaris, Mihail - Control of structural hierarchies and packing frustrations in block copolypeptide complexes
Perustieteiden korkeakoulu | Bachelor's thesis(2011) Haataja, Johannes - Halogeenisidoksen stabiloima hyvin erilaisten aineiden itsejärjestäytyminen
Perustieteiden korkeakoulu | Bachelor's thesis(2012) Poutanen, Mikko - Halogen-bonded mesogens direct polymer self-assemblies up to millimetre length scale
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2014) Houbenov, Nikolay; Milani, Roberto; Poutanen, Mikko; Haataja, Johannes; Dichiarante, Valentina; Sainio, Jani; Ruokolainen, Janne; Resnati, Giuseppe; Metrangolo, Pierangelo; Ikkala, OlliAligning polymeric nanostructures up to macroscale in facile ways remains a challenge in materials science and technology. Here we show polymeric self-assemblies where nanoscale organization guides the macroscopic alignment up to millimetre scale. The concept is shown by halogen bonding mesogenic 1-iodoperfluoroalkanes to a star-shaped ethyleneglycol-based polymer, having chloride end-groups. The mesogens segregate and stack parallel into aligned domains. This leads to layers at ~10 nm periodicity. Combination of directionality of halogen bonding, mesogen parallel stacking and minimization of interfacial curvature translates into an overall alignment in bulk and films up to millimetre scale. Upon heating, novel supramolecular halogen-bonded polymeric liquid crystallinity is also shown. As many polymers present sites capable of receiving halogen bonding, we suggest generic potential of this strategy for aligning polymer self-assemblies. - Hexagonal Microparticles from Hierarchical Self-Organization of Chiral Trigonal Pd3L6 Macrotetracycles
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2021-01-20) Jurček, Ondřej; Nonappa; Kalenius, Elina; Jurček, Pia; Linnanto, Juha M.; Puttreddy, Rakesh; Valkenier, Hennie; Houbenov, Nikolay; Babiak, Michal; Peterek, Miroslav; Davis, Anthony P.; Marek, Radek; Rissanen, KariConstruction of structurally complex architectures using inherently chiral, asymmetric, or multi-heterotopic ligands is a major challenge in metallosupramolecular chemistry. Moreover, the hierarchical self-organization of such complexes is unique. Here, we introduce a water-soluble, facially amphiphilic, amphoteric, chiral, asymmetric, and hetero-tritopic ligand derived from natural bile acid, ursodeoxycholic acid. We show that via the supramolecular transmetalation reaction, using nitrates of Cu(II) or Fe(III), and subsequently Pd(II), a superchiral Pd3L6 complex can be obtained. Even though several possible constitutional isomers of Pd3L6 could be formed, because of the ligand asymmetry and relative flexibility of carbamate-pyridyl moieties attached to the steroid scaffold, only a single product with C-3 rotational symmetry was obtained. Finally, we demonstrate that these amphiphilic complexes can self organize into hexagonal microparticles in aqueous media. This finding may lead to the development of novel self-assembled metal-organic functional materials made of natural, abundant, and relatively inexpensive steroidal compounds. - Hierarchical Self-Assembly of Halogen-Bonded Block Copolymer Complexes into Upright Cylindrical Domains
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2017-03-09) Milani, Roberto; Houbenov, Nikolay; Fernandez-Palacio, Francisco; Cavallo, Gabriella; Luzio, Alessandro; Haataja, Johannes; Giancane, Gabriele; Saccone, Marco; Priimagi, Arri; Metrangolo, Pierangelo; Ikkala, OlliSelf-assembly of block copolymers into well-defined, ordered arrangements of chemically distinct domains is a reliable strategy for preparing tailored nanostructures. Microphase separation results from the system, minimizing repulsive interactions between dissimilar blocks and maximizing attractive interactions between similar blocks. Supramolecular methods have also achieved this separation by introducing small-molecule additives binding specifically to one block by noncovalent interactions. Here, we use halogen bonding as a supramolecular tool that directs the hierarchical self-assembly of low-molecular-weight perfluorinated molecules and diblock copolymers. Microphase separation results in a lamellar-within-cylindrical arrangement and promotes upright cylindrical alignment in films upon rapid casting and without further annealing. Such cylindrical domains with internal lamellar self-assemblies can be cleaved by solvent treatment of bulk films, resulting in separated and segmented cylindrical micelles stabilized by halogen-bond-based supramolecular crosslinks. These features, alongside the reversible nature of halogen bonding, provide a robust modular approach for nanofabrication. - Maskless, High-Precision, Persistent, and Extreme Wetting-Contrast Patterning in an Environmental Scanning Electron Microscope
School of Electrical Engineering | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2016) Liimatainen, Ville; Shah, Ali; Johansson, Leena-Sisko; Houbenov, Nikolay; Zhou, Quan - Pentablock Copolymer Multicompartment Micelles and Their Complexes
Perustieteiden korkeakoulu | Master's thesis(2014) Haataja, Johannes - Polymer Brushes on Cellulose Nanofibers: Modification, SI-ATRP, and Unexpected Degradation Processes
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2017-09-05) Morits, Maria; McKee, Jason R.; Majoinen, Johanna; Malho, Jani Markus; Houbenov, Nikolay; Seitsonen, Jani; Laine, Janne; Gröschel, André H.; Ikkala, OlliControlled surface-initiated atom transfer radical polymerization (SI-ATRP) has previously been described as a versatile method that allows grafting polymer brushes on purely cellulosic forms of nanocelluloses, i.e., cellulose nanocrystal (CNC) nanorods and bacterial cellulose (BC) networks. However, corresponding SI-ATRP on long and entangled cellulose nanofibers (CNFs), having typically more complex composition and partly disordered structure, has been only little reported due to practical and synthetic challenges, in spite of technical need. In this work, the feasibility of SI-ATRP on CNFs is exemplified on the polymerization of poly(n-butyl acrylate) and poly(2-(dimethyl amino)ethyl methacrylate) brushes, both of which showed first order polymerization kinetics up to a chain length of ca. 800 repeat units. By constructing high and low initiator densities on CNF surfaces, we also show that, surprisingly, a higher grafting density of polymer brushes around CNF causes noticeable degradation of the CNF nanofibrillar backbone, whereas lower grafting densities retained the structural integrity of the CNF. We tentatively suggest that the side-chain brushes strain the disordered domains of CNF, causing degradation, which can be suppressed using a lower degree of substitution. Therefore, SI-ATRP of CNFs becomes subtler than that of, for example, CNCs, and careful balance has to be achieved between high density of brushes and excessive CNF degradation. - Reversible Supracolloidal Self-Assembly of Cobalt Nanoparticles to Hollow Capsids and Their Superstructures
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2017) Nonappa, Nonappa; Haataja, Johannes S.; Timonen, Jaakko V.I.; Malola, Sami; Engelhardt, Peter; Houbenov, Nikolay; Lahtinen, Manu; Häkkinen, Hannu; Ikkala, OlliThe synthesis and spontaneous, reversible supracolloidal hydrogen bond-driven self-assembly of cobalt nanoparticles (CoNPs) into hollow shell-like capsids and their directed assembly to higher order superstructures is presented. CoNPs and capsids form in one step upon mixing dicobalt octacarbonyl (Co2CO8) and p-aminobenzoic acid (pABA) in 1,2-dichlorobenzene using heating-up synthesis without additional catalysts or stabilizers. This leads to pABA capped CoNPs (core ca. 5nm) with a narrow size distribution. They spontaneously assemble into tunable spherical capsids (d≈50-200nm) with a few-layered shells, as driven by inter-nanoparticle hydrogen bonds thus warranting supracolloidal self-assembly. The capsids can be reversibly disassembled and reassembled by controlling the hydrogen bonds upon heating or solvent exchanges. The superparamagnetic nature of CoNPs allows magnetic-field-directed self-assembly of capsids to capsid chains due to an interplay of induced dipoles and inter-capsid hydrogen bonds. Finally, self-assembly on air-water interface furnishes lightweight colloidal framework films. - Supramolecular amplification of amyloid self-assembly by iodination
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2015) Bertolani, Arianna; Pirrie, Lisa; Stefan, Loic; Houbenov, Nikolay; Haataja, Johannes S.; Catalano, Luca; Terraneo, Giancarlo; Giancane, Gabriele; Valli, Ludovico; Milani, Roberto; Ikkala, Olli; Resnati, Giuseppe; Metrangolo, PierangeloAmyloid supramolecular assemblies have found widespread exploitation as ordered nanomaterials in a range of applications from materials science to biotechnology. New strategies are, however, required for understanding and promoting mature fibril formation from simple monomer motifs through easy and scalable processes. Noncovalent interactions are key to forming and holding the amyloid structure together. On the other hand, the halogen bond has never been used purposefully to achieve control over amyloid self-assembly. Here we show that single atom replacement of hydrogen with iodine, a halogen-bond donor, in the human calcitonin-derived amyloidogenic fragment DFNKF results in a super-gelator peptide, which forms a strong and shape-persistent hydrogel at 30-fold lower concentration than the wild-type pentapeptide. This is remarkable for such a modest perturbation in structure. Iodination of aromatic amino acids may thus develop as a general strategy for the design of new hydrogels from unprotected peptides and without using organic solvents. - Supramolecular Self-Assembly of Nanoconfined Ionic Liquids for Fast Anisotropic Ion Transport
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2019) Cherian, Tomy; Nunes, Danilo Rosa; Dane, Thomas G.; Jacquemin, Johan; Vainio, Ulla; Myllymaki, Teemu T. T.; Timonen, Jaakko V.; Houbenov, Nikolay; Marechal, Manuel; Rannou, Patrice; Ikkala, OlliMaterials involving nanoconfinement of ionic liquids (ILs) have been pursued for functionalities and ionic devices. However, their complex synthesis, challenges to achieve long-range order, and laborious tunability limit their practical implementation. Herein, these challenges are addressed by complexing surfactants to ILs, yielding a facile, modular, and scalable approach. Based on structural screening, ionic complexation of di-n-nonylamine to the terminal sulfonic acid of 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate IL is selected as a proof of concept. Spontaneous homeotropic smectic order over micrometers is observed, with alternating ionic and alkyl layers. The 1 nm thick ionic layers involve 2D crystalline internal order up to 150 degrees C, strongly promoting anisotropic ion transport (sigma(||)/sigma(perpendicular to) > 6500), and curiously, still allowing fluidity. High ionic conductivity of 35 mS cm(-1) and mesoscopic diffusion coefficient of approximate to 10(-5) cm(2) s(-1) at 150 degrees C along the ionic layers are observed. Fast anisotropic ion transport by simply complexing two components open doors to functional materials and applications. - Surface functionalization of nanofibrillated cellulose using click-chemistry approach in aqueous media
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2011) Pahimanolis, Nikolaos; Hippi, Ulla; Johansson, Leena-Sisko; Saarinen, Tapio; Houbenov, Nikolay; Ruokolainen, Janne; Seppälä, Jukka