Institute for Highly Pure Biopreparations

Saint Petersburg, Russia

Institute for Highly Pure Biopreparations

Saint Petersburg, Russia
SEARCH FILTERS
Time filter
Source Type

Trathnigg B.,Central Polymer Laboratory Molecular Characteristics CePOL MC | Gorbunov A.A.,Institute for Highly Pure Biopreparations
Journal of Chromatography A | Year: 2014

Di- and triblocks can be separated from each other under adsorption conditions for the outer block and critical or exclusion conditions for the inner block. If the center block is uniform, even a separation according to symmetry can be achieved. This behavior is studied in much detail by theory and simulations as well as in the chromatographic experiments with block copolymers of ethylene oxide and e{open}-caprolactone. © 2014 Elsevier B.V.


Gorbunov A.A.,Institute for Highly Pure Biopreparations | Vakhrushev A.V.,Institute for Highly Pure Biopreparations
Polymer | Year: 2010

A theory is developed for describing liquid chromatography of ring diblock and multiblock copolymers. The chromatographic behavior of ring block copolymers at different adsorption interactions is analyzed theoretically and compared with that of linear block copolymers; typical chromatograms are simulated by using the theory. In particular, it is shown that under the critical interaction condition for one block the chromatographic retention of a ring diblock copolymer is dependent of the length of the 'critical' block; this behavior differs qualitatively from that of a linear diblock copolymer. Ring copolymers are always more retained than linear ones, therefore such copolymers can be separated. Especially good separation of heterogeneous ring and linear block copolymers is predicted at near-critical interaction conditions. According to the theory, ring diblocks and multiblocks can be separated as well, if one component of a copolymer is adsorbing, while the other one is not adsorbing. © 2010 Elsevier Ltd.


Gorbunov A.A.,Institute for Highly Pure Biopreparations | Vakhrushev A.V.,Institute for Highly Pure Biopreparations
Procedia Chemistry | Year: 2010

Chromatography which is sensitive to the sizes of macromolecules and to their adsorption serves as an appropriate method to separate complex polymers. Unfortunately, the molar mass also influences the chromatographic retention, thus making quite difficult the problem of separation of polydisperse polymers by their topology. By using a theory of chromatographic behavior of macromolecules, we simulate chromatograms of polydisperse polymers that differ solely in their topology, and discuss possibilities to separate complex polymers (such as eight-, tadpole-, theta-, manacle-shaped polymers, etc.) from their linear, branched, or macrocyclic precursors or topo-isomeric products. As follows from the simulations, two approaches towards the separation of polydisperse polymers by topology are especially promising. The first one is the chromatography at optimized (critical or near-critical) interaction conditions, where molar-mass effects are minimized; The second one consists in combing different chromatographic modes, which allows obtaining a separation by both molar mass and topology in a 2D chromatogram. Some of the simulated chromatographic separations are qualitatively very similar to the real ones, the others are the theoretical prediction. © 2010.


Gorbunov A.A.,Institute for Highly Pure Biopreparations | Vakhrushev A.V.,Institute for Highly Pure Biopreparations
Journal of Chromatography A | Year: 2016

An analogy is established between functionalized polymers and partially cyclic macromolecules (PCMs) in the liquid chromatography at critical conditions (LCCC). Application of the functionalized chain analogy (FCA) for prediction of the behavior of complex multi-cyclic PCMs in the LCCC mode is demonstrated. By using FCA, we discuss possibilities of LCCC to separate multi-cyclic PCMs by the number of cycles, and with respect to molecular topology. FCA is also extended to describe PCMs with specifically adsorbing groups; this results in a simplified theory of LCCC of functionalized PCMs. By simulating chromatograms of heterogeneous functionalized PCMs at the conditions of LCCC, we show possible dramatic effects of functional groups on the topological separation of PCMs: even the retention order of components may change to opposite. © 2016 Elsevier B.V.


Vakhrushev A.V.,Institute for Highly Pure Biopreparations | Gorbunov A.A.,Institute for Highly Pure Biopreparations
Journal of Chromatography A | Year: 2016

A theory of chromatography is developed for partially cyclic polymers of tadpole- and manacle-shaped topological structures. We present exact equations for the distribution coefficient K at different adsorption interactions; simpler approximate formulae are also derived, relevant to the conditions of size-exclusion, adsorption, and critical chromatography. Theoretical chromatograms of heterogeneous partially cyclic polymers are simulated, and conditions for good separation by topology are predicted. According to the theory, an effective SEC-radius of tadpoles and manacles is mostly determined by the molar mass M, and by the linear-cyclic composition. In the interactive chromatography, the effect of molecular topology on the retention becomes significant. At the critical interaction point, partial dependences K(Mlin) and K(Mring) are qualitatively different: while being almost independent of Mlin, K increases with Mring. This behavior could be realized in critical chromatography-for separation of partially cyclic polymers by the number and molar mass of cyclic elements. © 2015 Elsevier B.V.


Gorbunov A.A.,Institute for Highly Pure Biopreparations | Vakhrushev A.V.,Institute for Highly Pure Biopreparations
Journal of Chromatography A | Year: 2010

Diblock copolymers, which are heterogeneous in both molar mass and composition, can be fully characterized by using two-dimensional chromatography. Since the size-exclusion, the adsorption, and the critical interaction based modes of chromatography are possible for each of the polymers A and B, this leads to a variety of options for 2D-chromatography of copolymers AB. Using the theory of chromatography of block copolymers, 2D-chromatograms are simulated that correspond to the most interesting of these options. Orthogonal 2D-chromatograms are expected, if in the 1st dimension the critical condition is created for A, while in the 2nd dimension - for B. The situations, where A and B are both adsorbable, as well as those where the conditions of adsorption for A and SEC for B are created, are also considered. In particular, it is shown that the 2nd dimension combination of the critical condition for A and SEC - for B is preferable than that with SEC condition for both A and B. The simulated 2D-chromatograms of low- and high molar mass diblock copolymers, as well as of copolymers with one short block are compared with the reported real ones; it is concluded that the corresponding virtual and real 2D-chromatograms are qualitatively very similar. © 2010 Elsevier B.V.


PubMed | Institute for Highly Pure Biopreparations
Type: | Journal: Journal of chromatography. A | Year: 2016

An analogy is established between functionalized polymers and partially cyclic macromolecules (PCMs) in the liquid chromatography at critical conditions (LCCC). Application of the functionalized chain analogy (FCA) for prediction of the behavior of complex multi-cyclic PCMs in the LCCC mode is demonstrated. By using FCA, we discuss possibilities of LCCC to separate multi-cyclic PCMs by the number of cycles, and with respect to molecular topology. FCA is also extended to describe PCMs with specifically adsorbing groups; this results in a simplified theory of LCCC of functionalized PCMs. By simulating chromatograms of heterogeneous functionalized PCMs at the conditions of LCCC, we show possible dramatic effects of functional groups on the topological separation of PCMs: even the retention order of components may change to opposite.


PubMed | Institute for Highly Pure Biopreparations
Type: | Journal: Journal of chromatography. A | Year: 2016

A theory of chromatography is developed for partially cyclic polymers of tadpole- and manacle-shaped topological structures. We present exact equations for the distribution coefficient K at different adsorption interactions; simpler approximate formulae are also derived, relevant to the conditions of size-exclusion, adsorption, and critical chromatography. Theoretical chromatograms of heterogeneous partially cyclic polymers are simulated, and conditions for good separation by topology are predicted. According to the theory, an effective SEC-radius of tadpoles and manacles is mostly determined by the molar mass M, and by the linear-cyclic composition. In the interactive chromatography, the effect of molecular topology on the retention becomes significant. At the critical interaction point, partial dependences K(Mlin) and K(Mring) are qualitatively different: while being almost independent of Mlin, K increases with Mring. This behavior could be realized in critical chromatography-for separation of partially cyclic polymers by the number and molar mass of cyclic elements.

Loading Institute for Highly Pure Biopreparations collaborators
Loading Institute for Highly Pure Biopreparations collaborators