ECIS2022 - 36th Conference

European Colloid & Interface Society

36th Conference of the European Colloid and Interface Society (ECIS 2022) that will take place from 4th to 9th September 2022 in Chania, on the island of Crete, Greece.

ECIS 2022 will be organized by the Hellenic Polymer Society, under the auspices of the ECIS, and aspires to bring together participants working in the interdisciplinary field of Colloid and Interface Science, with a broad background ranging from chemistry and physics to biology and engineering.

More info: https://ecis2022.org/oral-poster-awards/

Filter displayed posters (80 keywords)

droplet size distribution (2) electrodes (2) nanocomposite (2) nanofibers (2) nanotubes (2) polymers (2) self-assembly (2) solid contact (2) show more... AFM (1) Aβ40 (1) Bijel (1) DSC (1) Electroneutrality (1) Fibrillation (1) LDH; IL; nanosheets (1) LNP (1) MD simulations (1) OCNPs (1) Population Balance (1) QA/QC (1) SAXS (1) SAXS; SWAXS; XRD; pores; carbonization process (1) Shear (1) Small-angle X-ray scattering (SAXS) (1) UV/Vis spectroscopy (1) W/W emulsion (1) XRD (1) activated carbon (1) adsorption (1) amphiphile (1) anticancer (1) antimicrobial peptides (1) bending elasticity (1) calixarene (1) capsules (1) catanionic mixtures (1) chlorides (1) composite (1) confined kinetics (1) cytotoxicity in vitro (1) droplet interactions (1) droplets breakage (1) drug delivery (1) dye adsorption (1) electrical capacitance (1) emulsification (1) emulsions (1) environmental pollution (1) flotation (1) foamer (1) foaming ability (1) heterogeneous biocatalysis (1) inorganic-organic materials (1) interfacial shear viscosity (1) kaolin (1) keratin (1) lipid bilayers (1) lipid phase transitions (1) material emissions (1) micelles (1) microgravity (1) microspheres (1) molecular polymer brushes (1) nanomedicine (1) nitrates (1) octenidine (1) oscillating piston (1) polyelectrolytes (1) polymer (1) polypeptide(o)ides (1) porphyrin (1) protein immobilization (1) reference materials. (1) self-assembly pathways (1) surfactants (1) time-resolved SAXS (1) viscoelasticity (1) volatile organic compound (1) water treatment (1) wool (1)

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▼ Day 1 Back to top

Elucidation of self-assembly pathways in dilute catanionic surfactant solutions using TR-SAXS

Lauren Matthews, and Theyencheri Narayanan

Abstract

Self-assembly of surfactants can lead to a wide variety of structures, from simple spherical micelles to cylindrical aggregates, and at higher surfactant concentrations, ordered lyotropic phases. Upon mixing cationic and anionic surfactants unilamellar vesicles (ULVs) can form spontaneously[1-3]. At intermediate states along the pathway, different structural moieties may coexist[4]. The self-assembly pathways in catanionic mixtures have been studied in systems at relatively higher concentrations, where at least one of the surfactants was above the critical micelle concentration (CMC) [5, 6]. However, the pre-existing motifs, or the initial surfactant micelles, could bias the spontaneous formation to elongated aggregates. As a result, there is an interest to study these self-assembly pathways without an initial motif, in dilute concentrations well below their respective critical micelle concentrations (CMCs). Recent advances in synchrotron sources and X-ray detectors enable the investigation of such dilute solutions with millisecond time resolution. This work studies the self-assembly of structures formed in catanionic mixtures of cationic tetradecyltrimethylammonium bromide (TTAB) and anionic lithium perfluorooctanoate (LPFO) using time-resolved small-angle X-ray scattering (TR-SAXS) and rapid stopped-flow mixing. Both initial solutions were prepared at concentrations (csurf = 1.1 mM) well below that of the CMC (3.6 mM and 31 mM for TTAB and LPFO respectively). The behaviour is qualitatively similar to that in previously studies at higher concentrations, where the initial nonequilibrium structures observed are long wormlike structures (l > 104 nm), with a shell thickness consistent for a single bilayer of the mixed surfactants (tb ~ 4 nm). Further, these long aggregates reorganise with time to form ULVs, where the final morphology observed is a mixture of the wormlike shells and spherical ULVs. Whilst the spontaneous formation of disk-like or cylindrical aggregates in catanionic mixtures is expected, the formation of long wormlike structures occurs even without an initial motif. The evolution of these structures enables discussion of self-assembly and nonequilibrium structures in dilute solutions, furthering our understanding of the kinetic pathways in self-assembly processes.

Presented by

MATTHEWS LAUREN

Institution

The European Synchrotron Radiation Facility

Keywords

Small-angle X-ray scattering (SAXS), time-resolved SAXS, catanionic mixtures, self-assembly pathways

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Supramolecular Self-Assembly of Metallosurfactant and Porphyrin as a Drug Nanocontainer Design

Ruslan Kashapov, Yuliya Razuvayeva, Syumbelya Amerhanova, Anna Lyubina, Vadim Salnikov, Alexandra Voloshina, Lucia Zakharova

Abstract

The combined method of treating malignant neoplasms using photodynamic therapy and chemotherapy is undoubtedly a promising and highly effective treatment method. The development and establishment of photodynamic cancer therapy is closely related to the creation of sensitizers based on porphyrins. The present study is devoted to the investigation of the spectroscopic, aggregation and solubilization properties of the supramolecular system based on 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TSPP) and lanthanum-containing surfactant (LaSurf) in an aqueous medium. The latter is a complex of lanthanum nitrate and two cationic amphiphilic molecules of 4-aza-1-hexadecylazoniabicyclo[2.2.2]octane bromide. The mixed TSPP–LaSurf complexes can spontaneously assemble into various nanostructures capable of binding the anticancer drug cisplatin. Morphological behavior, stability and ability to drug binding of nanostructures can be tailored by varying the molar ratio and the concentration of components. The guest binding is shown to be additional factor controlling structural rearrangements and properties of the supramolecular TSPP–LaSurf complexes. Considering the targeted effect of porphyrin to cancer cells and the synergistic anticancer effect of cisplatin and lanthanum, the revealed physicochemical and biological properties of the ternary systems based on porphyrin, lanthanum-containing surfactant and platinum drug can be useful in creating an effective anticancer therapy.

Presented by

KASHAPOV RUSLAN <rusl701@yahoo.com>

Institution

Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center of RAS

Keywords

porphyrin, amphiphile, self-assembly, drug delivery

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Structure and electrostatic properties of polyelectrolyte dendrimer brushes

Pedro A. Sánchez, Joan J. Cerdà

Abstract

Presented by

SANCHEZ PEDRO A.

Institution

University of the Balearic Islands

Keywords

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Competing dynamics at play: self-assembly of colloidal particles with mobile DNA linkers

Pedro A. Sánchez, Alessio Caciagli, Jiaming Yu, Ren Liu, Xiaoying Tang, Sofia Kantorovich and Erika Eiser

Abstract

Presented by

SANCHEZ PEDRO A.

Institution

University of Vienna

Keywords

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Dr.

Danijela Bakarić

Abstract

The most distinctive quantities that describe structural features of lipid membranes are their phase transition temperatures which are usually determined by differential scanning calorimetry (DSC). Since the turbidity of lipid suspensions changes with temperature, it has recently been shown that UV/Vis spectroscopy can be used not only in the detection of phase transitions but also that low- and high-cooperative phase transitions can be recorded with almost equal sensitivity. In this regard, we have examined suspensions of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) in aqueous solution of NaCl (I = 100 mM) by temperature-dependent UV/Vis spectroscopy, DSC and molecular dynamics simulations. Aside the main phase transition temperatures (Tm) of DPPC ( 41 °C) and DPPE ( 63 °C) lipids and pretransition temperature (Tp) of DPPC ( 34 °C), multivariate analysis of acquired UV/Vis spectra of DPPE revealed certain changes in structural features on DPPE multilamellar aggregates about 10 degrees below Tm. Although this phenomenon does not appear in DSC curve of DPPE, the results of MD simulations imply that around this temperature the undulations of DPPE surface reach their maximum, but without formation of a ripple phase (like in DPPC). The results of this research unequivocally show that full potential of UV/Vis spectroscopy, coupled with appropriate multivariate approach, has yet to show itself in its full light in exploration of lipid bilayers structural features.

Presented by

BAKARIĆ DANIJELA

Institution

Ruđer Bošković Institute , Zagreb, Croatia

Keywords

lipid phase transitions, UV/Vis spectroscopy, DSC, MD simulations

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Design of an experimental device qualified for parabolic flights for the dynamic behaviour and stability study of emulsions

Angeliki P. Chondrou, Sotiris P. Evgenidis, Margaritis Kostoglou and Thodoris D. Karapantsios

Abstract

Emulsions are systems consisting of two immiscible liquids and are commonly found in oil, food and cosmetics industry. On earth, gravity triggers the rapid separation of aqueous phase from creamy phase after the end of emulsification process and, thus, motion of droplets as well as droplets’ interactions due to interface driven processes are evolving too fast to enable their investigation and in-depth understanding of underlying phenomena. Microgravity provides a simplified environment where gravity driven processes are eliminated, the motion of droplets and droplet-droplet interactions which strongly affect emulsion destabilization get slower and, as a result, can be studied thoroughly employing conventional diagnostics (e.g. optical and electrical methods). This study aims to exploit the low gravity conditions evolving during parabolic flights to study the dynamic behavior and stability of the produced emulsions. An experimental setup is under development, the core of which is the emulsification unit incorporating an innovated miniature pulsating emulsification device designed and constructed by Chondrou et al. [1]. Different advanced diagnostics will be used for monitoring emulsions’ dynamic behaviour and stability in low gravity conditions: A high speed camera for monitoring droplets breakup and motion, a high resolution camera for capturing images to determine oil droplet size distribution and a novel ultra-sensitive electrical impedance spectroscopy technique for recording the evolution of oil volume fraction and validate droplet size distribution. Four different parameters are about to be examined: a) Surfactant concentration, b) Piston stroke frequency, c) Oil to water ratio and d) Duration of emulsification.

Presented by

CHONDROU ANGELIKI

Institution

Aristotle University of Thessaloniki

Keywords

emulsions, droplet interactions, microgravity, droplet size distribution

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Effect of oscillating piston characteristics on small volume emulsion generation

Angeliki P. Chondrou, Thodoris D. Karapantsios and Margaritis Kostoglou

Abstract

A miniature pulsating device has been designed and constructed for emulsification experiments. The core of the device is an experimental cell while the necessary shearing for the proper mixing of the two liquids is generated by the linear periodic movement of a piston up and down inside the cell. For the present study, five different pistons are constructed which differ in the length or in the height of their plate sides. These features dictate different width and height of the gap between the plate and the cell walls. Their performance is assessed by performing emulsification experiments over a wide variety of piston stroke frequency and emulsification duration for a specific non-coalescing system (fixed oil fraction and surfactant concentration). The resulting droplet size distributions are estimated by monitoring the evolution of phase separation versus time and determining the initial oil droplet size distribution by means of optical measurements. The combined information from these techniques is necessary in order to register the broad size range of droplets. A semiquantitative analysis of the flow field in the gap reveals that droplet breakage process starts at the laminar boundary layers developed between the piston and the cell walls and allows characterization of this field. A discussion on the mechanism of droplet breakup is presented. The analysis of experimental results demonstrates that four of the five tested piston plates are appropriate for emulsification regarding the generated droplet size distribution and the choice among them requires additional criteria, e.g. energy requirements.

Presented by

CHONDROU ANGELIKI <apchondr@chem.auth.gr>

Institution

Aristotle University of Thessaloniki

Keywords

emulsification, oscillating piston, droplet size distribution, droplets breakage

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Interfacial shear viscosity and surface tension measurements of anionic–nonionic surfactant binary mixtures, used as minerals flotation reagents

Ourania Oikonomidou, Christos Koukiotis, Margaritis Kostoglou and Thodoris Karapantsios

Abstract

Binary mixtures of ionic - nonionic surfactants feature enhanced interfacial properties compared to the individual ionic and nonionic surfactant components. In terms of minerals flotation technology, these binary mixtures can be used as collector reagents and they are expected to improve bubble-particle attachment efficiency and thus facilitate the recovery of mineral particles. Up to date, the synergistic action of ionic and nonionic surfactant molecules, has been studied by performing static surface tension measurements. For the first time, the present work tests interaction between sodium oleate (NaOl, anionic surfactant) and five different ethoxylated/ alkoxylated alcohols (nonionic surfactants) by measuring the interfacial steady shear viscosity of their aqueous solutions at a wide range of shear rates. Measurements are conducted using a Physica MCR 301 Anton Paar rheometer equipped with an Interfacial Rheology System (IRS) employing a bicone bob geometry. Different anionic-nonionic mass ratios are tested, keeping the concentration of NaOl at 1 CMC (300ppm). Results show that nonionic molecules tend to displace NaOl molecules from the air/liquid interface. Above some critical nonionic surfactant concentration, interfacial shear viscosity of the binary mixture is governed by the nonionic molecules, indicating that these molecules occupy the interface. However, supporting surface tension measurements show that at this critical concentration there are still NaOl molecules attached on the interface. Critical concentration level depends on the chemical structure of nonionic molecules, i.e. length of the hydrophilic head, branch at the hydrophobic chain. Furthermore, oscillatory rheological runs reveal the dominant viscous character of all tested binary mixed monolayers with only a marginal elastic component.

Presented by

KARAPANTSIOS THODORIS <karapant@chem.auth.gr>

Institution

Aristotle University of Thessaloniki, School of Chemistry, Department of Chemical Technology

Keywords

interfacial shear viscosity, viscoelasticity, surfactants, flotation

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Tuning of Nanoparticles Based on Amphiphlic Calix[4]resorcinol and Octenidine for Enhanced Anticancer Activity and Selectivity

Nadezda Kashapova, Ruslan Kashapov, Albina Ziganshina, Syumbelya Amerhanova, Anna Lyubina, Vadim Salnikov, Alexandra Voloshina, and Lucia Zakharova

Abstract

Well-known commercial anticancer drugs do not provide sufficient selectivity of action, affecting both cancerous and healthy cells alike. The reduction of side effects in the treatment of cancer can be achieved by creating new dosage forms with a high selectivity index [1]. Incorporating drugs into nanoparticles of various nature is an effective way to reduce the side effects of anticancer drugs. The cationic gemini surfactant octenidine dihydrochloride, known as a commercial antimicrobial drug, also exhibits high anticancer activity on various cell lines [2]. In order to reduce the toxicity of octenidine on normal cells and increase the selectivity of action in vitro, in present work the spherical nanoparticles based on octenidine and macrocyclic acetate derivatives of calix[4]resorcinols were obtained. Nanoparticles with macrocycle containing saturated alkyl chains in the structure turned out to be more stable over time than nanoparticles with macrocycle that differs only in the presence of one double bond in the alkyl chains. The TEM images confirm the formation of particles with a diameter of ~100 nm with a vesicular shape. The study of cytotoxicity showed that these nanoparticles exhibit high activity on tumor cell lines (HuTu 80, MCF-7), while there is a sharp decrease in toxicity compared to pure octenidine on normal cells (Chang liver). Thus, the mixed surfactant–macrocycle nanoparticles are 7 times more active and 20 times more selective than the commercial anticancer drug doxorubicin on the HuTu 80 cell line, which gives grounds to consider them as promising drug candidates.

Presented by

KASHAPOVA NADEZDA

Institution

Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center of RAS, 420088 Kazan, Russia

Keywords

calixarene, self-assembly, octenidine, cytotoxicity in vitro, anticancer

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A model for Bubble-Particle Collision Frequency in a Turbulent Flow Field

M. Kostoglou, T.D. Karapantsios

Abstract

Process modeling is a valuable tool for process design and optimization. Nonetheless, the extent of its use depends on the physical complexity of each particular application. Dispersed air flotation is one of the most complex processes to model. In particular, in mechanical flotation cells, turbulent flow prevails and promotes bubble-particle collisions. Many size and time scales of both hydrodynamic and physicochemical nature have to be resolved to model the process. The only way to achieve this is a combination of co-current (pulp and froth) and sequential multiscale modeling. A generalized framework for modeling the pulp phase from the device scale to thin film scale separating bubbles and particles is discussed here. The core of the model is the term describing the collision frequency between bubbles and particles. Existing approaches to derive this term are reviewed and critically commented demonstrating several inconsistencies. A unified and consistent approach for deriving this collision frequency term is described overcoming all the inconsistencies of previous approaches. The schematic of the steps leading to an expression for this frequency is shown in Figure 1. Specific results are presented for the case of flotation of fine particles, being practically the only case for which a simplified collision frequency expression of algebraic complexity can be derived.

Presented by

KOSTOGLOU MARGARITIS

Institution

Aristotle University of Thessaloniki, School of Chemistry

Keywords

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Kinetics of aggregation of amyloid β under different shearing conditions: Experimental and modelling analyses

Sriram Krishnamurthy, Ethayaraja Mani, Swathi Sudhakar

Abstract

Amyloid β (Aβ40) is a class of amyloidogenic proteins known to aggregate into a fibrillar network. The rate of aggregation and fibril yield is sensitive to external energy input, such as shear. In this work, simple shear and shaking experiments are performed on Aβ40 solution using a Couette cell and an orbital shaker, respectively. Experiments show that, under uniform shear, both the mass of fibrils and aggregation rate increase with the shear rate. In the case of orbital shaking, the lag time decreases with the rotational speed of the shaker, but the final fibril mass is the same for all agitation speeds. To explain this contrasting behaviour of aggregation kinetics, a population balance model is developed to account for the effect of shear on the aggregation of Aβ. The kinetic model includes primary nucleation, secondary nucleation, and elongation, fragmentation, and depolymerization steps. The effect of steady uniform shear is encoded in the depolymerization rate constant (), and it is shown that decreases with shear rate initially and saturates at high shear rates. A competition between elongation and depolymerization rates yields different equilibrium masses of fibril at different shear rates. The model results agree quantitatively well with experimental data on the rate of aggregation and mass of fibrils as a function of shear rate

Presented by

KRISHNAMURTHY SRIRAM

Institution

Indian Institute of Technology Madras

Keywords

Aβ40, Population Balance, Shear, Fibrillation

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Droplet-Bijel-Droplet Transition in Aqueous Two-Phase Systems Stabilized by Oppositely Charged Nanoparticles: A Simple Pathway to fabricate Bijels

Chandra Shekhar, Abhimanyu Kiran, Vishwajeet Mehandia, Venkateshwar Rao Dugyala, Manigandan Sabapathy

Abstract

In this work, we demonstrate a novel yet straightforward methodology of stabilizing aqueous twophase systems (ATPS) using oppositely charged nanoparticles (OCNPs). We employ commercial grade, Ludox, OCNPs to induce self-assembly. This self-assembly route promotes the stronger adsorption of nanoparticles at the water− water interface by triggering the formation of 2D and 3D aggregates of varying sizes and shapes. The interplay of this size and shape promotes stability due to increased Gibbs detachment energy and modulates the resulting cluster adsorption at the interface, thereby the structural state of emulsions. We demonstrate the influence of polymers and particles’ composition on the structural transformation from droplet−bijel− droplet using a phase diagram. For the first time, such a structural transition and the single pathway are reported within the domain of ATPS to produce stable bijels or colloidal capsules. It is asserted that the essential condition of three-phase contact angle (θ) = 90° to favor the formation of bijels can be established by selecting a suitable experimental condition using a phase diagram without employing any complicated surface modification procedures reported in the literature. Further, the mechanistic route favoring the formation of bijels and emulsion droplets at different experimental regimes is presented based on the empirical study using turbidity and zeta potential measurements. These studies reveal that the formation of bijels will be most favored when the parameter M (ratio of weight fraction of positively charged nanoparticles to negatively charged nanoparticles) is chosen between 0.7 and 4. It is intriguing to note the fact that, while the droplets stabilized by OCNPs have shown good resilience under high centrifugal action, the bijels produced in this way continued to remain stable for a long time, offering a facile route to prepare the bijels with a hierarchical Bicontinuous network structure.

Presented by

SHEKHAR CHANDRA <2018chz0002@iitrpr.ac.in>

Institution

Indian Institute of Technology, Ropar

Keywords

W/W emulsion, Bijel, Electroneutrality, OCNPs

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Dispersions of Delaminated Double Hydroxides in Ionic Liquids

Dóra Takács,1,2 Matija Tomšič,3 Gábor Varga,2 Edit Csapó, 2 Andrej Jamnik, 3 and István Szilágyi.1,2

Abstract

We studied the delamination of layered double hydroxide (LDH) particles into the nanosheets, which was triggered in the liquid phase and resulted in stable dispersions. The mesoporous LDHs were prepared by a template-free method [1] and dispersed in two different ionic liquids (ILs), i.e., ethylammonium nitrate (EAN) and 1-butyl-3-methylimidazolium thiocyanate (BMIMSCN). Small-angle X-ray scattering (SAXS), X-ray diffraction (XRD) and atomic force microscopy (AFM) were used. The latter provided the height profile of the dried dispersed nanoparticles on a freshly cleaved mica. The generalized inverse Fourier transform method [2] was used to analyze the SAXS data and provided the corresponding thickness-pair distance distribution functions (tPDDFs) of the dispersed nanosheets in bulk solutions. Delamination of the LDHs was confirmed in ILs but not in water.

Presented by

TOMSIC MATIJA <matija.tomsic@fkkt.uni-lj.si>

Institution

1MTA-SZTE Lendület Biocolloids Research Group, University of Szeged, H-6720 Szeged, Hungary 2Department of Physical Chemistry and Materials Science, University of Szeged, H-6720 Szeged, Hungary 3Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia

Keywords

LDH; IL; nanosheets, AFM, SAXS, XRD

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Structural study of non-graphitizable carbons from corn cobs for negative sodium ion battery electrodes

Blaž Tratnik,1,2 Matija Tomšič,2 Nigel Van de Velde,1 Ivan Jerman,1 Gregor Kapun,1 Elena Tchernychova,1 Andrej Jamnik,2 Boštjan Genorio,2 Alen Vizintin,1 and Robert Dominko.1-3

Abstract

Sodium-ion batteries (SIBs) are an attractive alternative to lithium-ion batteries for large-scale energy storage applications because they are made from low-cost, abundant, and less toxic raw materials [1]. Non-graphitizable carbons are the best option for the negative electrode in SIBs. We performed a detailed structural study of non-graphitizable carbon powders from corn cobs prepared at different carbonization temperatures from 900 °C to 1600 °C. It is based on scanning transmission electron microscopy (STEM) and small- and wide-angle X-ray scattering (SWAXS) curves, which contain structural information over a wide range of structural length scales, as shown in Fig. 1. These curves were fitted by an equation with three main contributions, from which a number of structural parameters were obtained [2,3]. The results show a trend of increasing structural order with increasing carbonization temperature, as demonstrated by unconventional parameters such as the correlation at which order is lost, the fractal cut-off length, and the lengths of the locally flat regions.

Presented by

TOMSIC MATIJA <matija.tomsic@fkkt.uni-lj.si>

Institution

1National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia 2FKKT, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia 3ALISTORE-European Research Institute, CNRS FR 3104, Hub de l’Energie, Rue Baudelocque, 80039, Amiens Cedex, France

Keywords

SAXS; SWAXS; XRD; pores; carbonization process

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▼ Day 2 Back to top

“Nanomedicine based on Polypept(o)ides”

Matthias Barz

Abstract

The enormous potential of polymeric nanoparticles, in in particular polymeric micelles, arises from the possibility to combine desirable material properties with compartmentalized functionalities within one distinct system.[1] Synthetic complexity is an enormous hurdle or maybe the major drawback for cost-effective industrial production or clinical translation and can prevent even the most effective polymeric systems from entering the market or becoming approved drugs, since it complicates up-scaling and can affect reproducibility of materials.[2] Therefore, a major task for polymer chemists is –besides the synthesis of new materials- the development of synthetic methods, which intrinsically reduce chemical complexity, while preserving the desired functionalities. With respect to these needs, we have introduced polypept(o)ides (polypeptoid-block-polypeptide copolymers), which can be synthesized by living ring opening polymerization providing precise control over molecular weights, low polymer dispersities and high end group integrities. Furthermore, this class of materials is completely based on endogenous amino acids and combines the stealth-like properties of polysarcosine with the multi-functionality of polypeptides.[3,4] This toolbox enables the synthesis of core cross-linked micelles [5] & nanohydrogels [6], bottlebrush [7] & star-like polymers [8], polymersomes [9] and polyplexes[10]. Either bottom up-synthesis or directed self-assembly provide control over particle morphology and function. Besides, the secondary structure formation of polypeptides can be used to direct the self-assembly process of polypept(o)ides in aqueous solution. The combination of secondary structure directed assembly and functionalities beyond nature’s possibilities within these polymers leads to novel materials for a multitude of applications.

[1] Blanco, E. et al. Nature Biotechnol. 2015, 33, 941-51. [2] Barz, M. Nanomedicine 2015, 10 (20), 3093-97. [3] a) Birke, A. et al. Progress Polym. Sci. 2018, 81, 163-208; b) Klinker, K, Barz M. Macromol. Rapid Commun. 2015, 36 (22), 1943-57. [4] a) Huesmann, D.; Klinker, K.; Barz M. Polymer Chemistry 2017,8, 957-71; b) Schäfer, O. et al. Chem. Euro. J. 2016, 22 (50), 18085-91; c) Schäfer, O. et al. Macromolecules 2016, 49 (21), 8146-53. [5] a) Talleli, M. et al. Nano Today 2015, 10 (1), 93-117; b) Birke, A. et al. Biomacromolecules 2014, 15 (2), 548-57; c) Klinker, K. et al. Angew. Chem. Int. Ed. 2017, 56, 9608-13; d) Johann K. et al. Nat. Commun. 2021, 12 (1), 1-9; e) Bauer T. A. Adv. Health. Mat. 2021, 10 (19), 2170086; e) Siemer, S.; Bauer T.A. et al. ACS nano 2021, 15 (11), 18541-18556. [6] Klinker, K. et al. Angew. Chem. Int. Ed. 2017, 56 (32), 9608–13. [7] Hoertz, C.; Birke, A. et al. Macromolecules 2015, 48 (7), 2074-86; Kappel, C.; Seidl, C.I. et al. ACS Nano 2021, 15 (9), 15191-15209. [8] a) Tsvetkova, Y. et al. Nano Lett. 2017, 17 (8), 4665-4674; b) Holm, R. et al. Macromol. Biosci. 2017, 17 (6), 1600514. [9] Weber, B. et al. Macromol. Biosci. 2017, DOI: 10.1002/mabi.201700061. [10] a) Heller, P. et al. Macromol. Biosci. 2014, 14 (10), 1380-95; b) Heller, P. et al. Small 2017, DOI: 10.1002/smll.201603694. c) Heller, P. et al. J. Control. Release 2017, 258, 146-60.

Presented by

MATTHIAS BARZ

Institution

Leiden Academic Center for Drug Research (LACDR) Leiden University Einsteinweg 55, 2333 CC Leiden The Netherlands

Keywords

polymers, polypeptide(o)ides, nanomedicine, LNP, micelles, molecular polymer brushes

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“Preparation and properties of keratin foamer“

Zhanar Ospanova1, Kuanyshbek Musabekov1, Kuandyk Mamyr1, Meruert Sultan1, Paul Takhistov2

Abstract

According to statistics, every year more than 40 thousand tons of wools, hooves and horns are got rid of as waste from slaughterhouse in Republic of Kazakhstan. The thrown away wastes from slaughterhouse such as wool, horn, hoofs cause the environmental pollution and it might be harmful to human’s health. The aim of our work is - to synthesize keratin foam formers from this waste material and use it for human needs. Liquid keratin is most widely known for its foaming ability which is very suitable for firefighting and construction and many other branches of science. As a result of research on the interaction of keratin and a base, a special condition of foaming and temperature has been made. Proteins from the different classes of wool keratins possess characteristics that give them unique advantages in specific applications [1]. Wool and hair are examples of hard α-keratin. All keratins are characterized by a high level of the sulphur-containing diamino-acid cystine, which acts as a cross-linking point between protein chains [2]. The obtained hydrolyzed liquid leveled to pH=6.8 FeSO4•7H2O and some polymers are added to improve the foaming ability and the stability of foam surface tension, and lifetime. Foaming stability is measured in various concentrations of liquid. As a result, the keratin foam showed very good results and its foaming stability lasted for 5 hours. And it’s proved that keratin foams which we synthesize can be used for fire-fighting and construction. We also studied the infrared spectra of samples of hydrolysates. The expected structure of the sample corresponds to the presence of amino acids with a peptide bond. The advantage of this technology is that it is simple, cheaper, and that synthesized liquid has great foaming. Keywords: environmental pollution, keratin, wool, foaming ability, foamer Session 2nd choice: Colloids at Interfaces, Membranes and Biointerfaces, Emulsions and Foams References [1] Robert James Kelly, Mohammad Azam Ali, Alisa Dawn Roddick-Lanzilotta, Gillian Worth, Mohammad Mahbubul Hassan, John Robert McLaughlin, Alan John McKinnon, Composite materials containing keratin, Pat. 7767756. Keraplast Technologies, Ltd./. Filed: September 13, 2004. Issued: August 3, 2010 [2] M. Cardamone, A. Nuñez, R.A. Garcia, M. Aldema-Ramos, Research Letters in Materials Science, 2009, Article ID 147175

Presented by

ZHANAR OSPANOVA

Institution

1 Al-Faraby Kazakh National University, Almaty Kazakhstan; 2 Rutgers the State University of New Jersey, New Brunswick, United States

Keywords

environmental pollution, keratin, wool, foaming ability, foamer

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Pyrolysis atmosphere impact on the textural properties and the surface chemistry of activated carbons

Magdalena Zięzio , Barbara Charmas, Karolina Kucio

Abstract

Presented by

ZIĘZIO MAGDALENA

Institution

Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University, Lublin

Keywords

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Synthesis and application of CoFe2O4/TiO2 doped activated carbon based nanophotocatalysts

Magdalena Zięzio, Barbara Charmas, Karolina Kucio

Abstract

Presented by

ZIĘZIO MAGDALENA

Institution

Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University, Lublin

Keywords

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Polymeric Capsules with VOCs for Controlled Emission

Anna Musyanovych, Christoph Grimmer, Ali Enis Sadak, Lorenz Heßling, Mine Bilsel, Wolfgang Horn, Matthias Richter

Abstract

Micro-(nano-)encapsulation technology involves building of a barrier between the core and the environment and offers several benefits to preserve the functional and physicochemical properties of core material. Tremendous progress has been made in synthesizing well-defined capsules to achieve desired properties such as particle size, chemical composition, and controlled release of the payload. Encapsulation of volatile organic compounds (VOCs) that could evaporate with a defined rate is of immense interest for application in emission reference materials (ERM). These are urgently needed for quality assurance and quality control purposes (QA/QC) required by test standards for the determination of chemical emissions of construction and other materials for interior use. As such ERMs are hardly available on the market, the EU-funded EMPIR project MetrIAQ [1] was started to fill this gap by developing a material with temporally constant emission of VOCs typically found in indoor air. Different capsules in a size range between 5 and 50 µm were synthesized through an interfacial polyaddition/polycondensation reaction in direct (water-in-oil) system. As VOC several types of hydrophobic liquid materials were used. After synthesis, the morphology and physicochemical properties of capsules were characterized by electron microscopy, FTIR and DSC/TGA. An encapsulation efficiency up to 90% could be reached. The emission kinetic of volatile agents was studied in emission test chambers at 23 °C and 50% RH for 14 days. First results indicate that variation of the cross-linking grade of the shell material is one important parameter to adjust the desired emission rate. The overall aim is to achieve a consistent emission profile that decreases by less than 10 % over a target period of at least 14 days.

Presented by

Anna Musyanovych

Institution

Fraunhofer IMM, Mainz, Germany

Keywords

capsules, volatile organic compound, polymer, material emissions, QA/QC, reference materials.

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Kaolin-based composites structural, morphological, thermal, and adsorption characteristics

Alicja Bosacka, Viktoriia Paientko, Olena Oranska, Natalia Stolyarchuk, Roman Kozakevych, Stanislaw Sevostyanov, Yuri Lytvynenko, Aleksander Matkovsky, Volodymyr Gun’ko, Malgorzata Zienkiewicz-Strzalka, Anna Derylo-Marczeska, and Agnieszka Chrzanowska

Abstract

Kaolin is a hydrated aluminum silicate with a crystalline structure [1]. Activated carbon is carbon produced from a carbonaceous source such as bamboo, coconut husk, willow peat, or wood [2]. Both, kaolin, as well as activated carbon, are used as adsorbent systems for the removal of dyes (or other organic pollutants) from wastewater because of their porous characteristics [3]. In this work, the kaolin-carbon composites were obtained by mechanochemical activation using a knife-milling. The influence of the differentiated composition of kaolin-based composites on their structural, morphological, porous, thermal, or acid-base properties was examined. Moreover, the studies of the adsorption of the selected dyes on the proposed adsorbents were carried out.

Presented by

BOSACKA ALICJA

Institution

Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie-Sklodowska Sq. 3, 20-031 Lublin, Poland, Chuiko Institute of Surface Chemistry, National Academy of Sciences, 17 General Naumov Street, 03164 Kyiv, Ukraine, M. P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation, National Academy of Sciences, Akademika Palladina Avenue 34A, 03680 Kyiv, Ukraine

Keywords

kaolin, activated carbon, composite, dye adsorption

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Physicochemical and adsorption properties of polymer microspheres as materials for the removal of organic compounds

Alicja Bosacka, Małgorzata Zienkiewicz-Strzalka, Anna Derylo-Marczewska, Agnieszka Chrzanowska, Małgorzata Wasilewska, and Beata Podkoscielna

Abstract

Water contamination caused by industrial processes is a common global problem. Organic pollutions (benzene derivates, dyes, pharmaceuticals) are hazardous substances that do not decompose easily in water. For this reason, novel adsorbents for water or wastewater purification from organic compounds are the subject of search [1-3]. Polymers are characterized by numerous beneficial properties encompassing tensile strength, modulus, toughness, or viscoelasticity, however, these materials have some limitations in their usage because of the inferior mechanical or thermal properties in comparison to metals or ceramics. To improve polymer features the combination of them in the form of a muli-phase system could be an appropriate solution. Porosity is one of the major factors affecting the adsorption properties of adsorbents. The difference in the composition of adsorbents may cause distinctions in their porous system [4]. In this work, the two-phase polymer microspheres with different compositions were received in the emulsion-suspension polymerization reaction. The structural, porous, morphological, thermal, and adsorption properties of inorganic-organic materials were examined using several instrumental techniques: scanning electron microscopy (SEM), Fourier transform infrared/attenuated total reflection spectroscopy (FT-IR/ATR), nitrogen low-temperature adsorption-desorption, and thermal analysis. Also, the kinetic and equilibrium adsorption studies revealed the potential applicability of these adsorbents in the removal of aromatic organic compounds from water or wastewater.

Presented by

BOSACKA ALICJA

Institution

Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie-Sklodowska Sq. 3, 20-031 Lublin, Poland

Keywords

inorganic-organic materials, polymers, microspheres, adsorption, water treatment

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Study of the stability of gas/liquid interfaces in liquid bridges using an electrical conductance method

M. Kostoglou, A, Zamanis, T.D. Karapantsios

Abstract

Air-liquid interfaces and the liquid film between them are structural characteristics of foams so their study is of particular importance to determine foam stability. Specifically, the more stable the interfaces are, the more stable the foam will be. A new electrical technique for the study of these interfaces’ stability, is proposed in the present work. In particular, a bubble is created inside the liquid bridge. The latter is surrounded by air, creating interfaces and liquid films similar to those found in a foam. During control drainage of the liquid bridge, electrical measurements take place. Through these measurements, it is possible to determine the stability of the film created between the bubble and the liquid bridge and consequently to estimate the stability of the foam generated by the type and amount of employed surfactant. Experiments took place with liquid bridges of various solutions of surfactants (e.g. SDS, BaC 50, Ethylan 1008) at different concentrations, for various mixtures of the above surfactants, in the presence and in the absence of NaCl, under stable ambient conditions (i.e. temperature and moisture), and for various liquid drainage rates (e.g 10 and 20μl/h). These experiments showed that the highest the concentration of the surfactant, the highest the strength against thinning of the liquid film and so the longest the time until its rupture, thus the stability of the foam created for the particular concentration of surfactant is also the highest.

Presented by

KOSTOGLOU MARGARITIS

Institution

Aristotle University of Thessaloniki, School of Chemistry

Keywords

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Biomimetic membranes interacting with pro-apoptotic peptides

Victoria Vitkova1 , Angelina Stoyanova-Ivanova 1 , Ognyan Petkov 1* , Sirine Jaber 2 , Emilia Naydenova 2 , Georgi Popkirov 3 and Dancho Danalev 2

Abstract

Synthetic antimicrobial peptides with bacteriostatic and cytotoxic activity are designed to exhibit modified selectivity and propensity to α-helical conformation in amphipathic environment. Our previous studies on a series of shortened analogues of (KLAKLAK)2 revealed that KLβAKLβAK-NH2 has very good antiproliferative effect against MCF-7 tumor cell lines with SI = 8.35. Moreover, its activity against MCF-7 tumor cell lines is more than 11 times higher than those of parent molecule KLAKLAK-NH2 [1]. On the other hand, doubled sequenced parent compound (KLAKLAK)2-NH2 shows around 10 times higher antiproliferative effect in comparison with doubled analogue containing β-Ala (KLβAKLβAK)2-NH2 in the primary structure [2]. Here we probe the ability of these compounds containing natural or unnatural amino acid β-Ala to penetrate cell membrane thus initializing apoptosis. The bending rigidity of model lipid bilayers is measured by thermal shape fluctuation analysis of quasispherical unilamellar vesicles monitored in phase contrast light microscopy. The electrical properties of planar lipid bilayers are assessed by fast Fourier transform electrochemical impedance spectroscopy. At peptide concentrations of ~20÷30 µmol/L and peptide-to-lipid total molar ratios ~0.55÷0.80 the membrane bending elasticity is unaltered, which indicates transbilayer insertion of the shortened non-modified analogue. The acquired results provide useful knowledge in tailoring the structure of antimicrobial peptides to achieve strengthened stability towards enzymatic degradation.

Acknowledgements: Financial support of Bulgarian National Science Fund (KP-06-N58/6/2021) is acknowledged.

References:

[1] S. Jaber, I. Iliev, T. Angelova, V. Nemska, I. Sulikovska, E. Naydenova, N. Georgieva, I. Givechev, I. Grabchev, D. Danalev, Molecules 2021, 26, 898, https://doi.org/10.3390/molecules26040898

[2] S. Jaber, V. Nemska, I. Iliev, E. Ivanova, T. Foteva, N. Georgieva, I. Givechev, E. Naydenova, V. Karadjova and D. Danalev, Molecules 2021, 26, 7321, https://doi.org/10.3390/molecules26237321

Presented by

PETKOV OGNYAN

Institution

1 Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 2 University of Chemical Technology and Metallurgy, 3 Central Laboratory of Solar Energy and New Energy Sources, Bulgarian Academy of Sciences

Keywords

lipid bilayers, bending elasticity, electrical capacitance, antimicrobial peptides

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Testing water samples for the content of nitrate ions using ion-selective electrodes with solid contact

Karolina Pietrzak and Cecylia Wardak

Abstract

Research on ion-selective electrodes with solid contact (SCISEs) is currently very popular among scientists dealing with potentiometric methods. In order to obtain sensors with the best analytical parameters, it is necessary to use new materials for their construction. The improvement of their properties is most often influenced by the modification of the membrane composition (in particular, the change of the active substance for better selectivity and sensitivity of the electrode) and the addition of a substance acting as a solid contact in order to ensure the stability and reversibility of the sensor potential. Potentiometric sensors useful for determining nitrate ions in environmental samples with the use of various materials as a solid contact - nanocomposite of multiwalled carbon nanotubes with an ionic liquid (MWCNTs-IL) [1] and polyaniline nanofibers doped with chloride and nitrate ions (PANINFs-Cl and PANINFs-NO3) [2] were constructed. Measurements were made for electrodes differing from each other both in the place of occurrence of the solid contact (the intermediate layer between the electrode material and the ion-selective membrane and a direct addition to the membrane mixture) and the amount of material used (thickness of the intermediate layer and the content of the additive in the membrane). The obtained values of analytical parameters were compared, such as: the slope of the electrode characteristic curve, linearity range, detection limits, stability and reversibility of the potential, as well as the electrical: capacitance and resistance of the ion-selective membrane. In order to better investigate the influence of the materials used on the work of the electrodes, unmodified electrodes were also made, in which only the basic membrane mixture was spotted on the electrode surface. On the basis of the obtained results, the best electrodes were selected and used to determine concentration of nitrate ions in water samples: river, ground and drinking water.

Presented by

PIETRZAK KAROLINA

Institution

Maria Curie-Sklodowska University, Department of Analytical Chemistry

Keywords

nanocomposite, nanofibers, nanotubes, electrodes, solid contact, nitrates

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Chloride SCISEs based on a nanocomposite of polyaniline nanofibers and multiwalled carbon nanotubes (PANINFs-Cl:MWCNTs)

Karolina Pietrzak, Cecylia Wardak, Szymon Malinowski and Małgorzata Grabarczyk

Abstract

Among the potentiometric sensors, ion-selective electrodes without an internal electrolyte solution (electrodes with solid contact, SCISEs), are gaining more and more popularity. These types of electrodes are characterized by very good analytical parameters, often even better than their classic predecessors. Their main advantage is simple structure, low production cost, mechanical resistance and the possibility of miniaturization and operation in any position. A special material (so-called solid contact) responsible for ensuring the appropriate stability and reversibility of the electrode potential is placed between the material of the inner electrode and the ion-selective membrane layer. Various materials are used as solid contacts, for example conductive polymers[1], nanoparticles[2], nanofibers[3], carbon-based nanomaterials and nanocomposites synthesized for this purpose[4,5]. The work describes the use of a nanocomposite consisting of polyaniline nanofibers doped with chloride ions with multiwalled carbon nanotubes as a solid contact in the construction of chloride ion-selective electrodes. Nanocomposites with various weight ratios of PANINFs-Cl:MWCNTs were obtained and used as an intermediate layer. The properties of nanocomposites and the intermediate layers obtained from them were investigated, and then electrodes differing in the type of solid contact were constructed. In addition to electrodes with nanocomposites, unmodified electrodes with only basic membrane or with additional layer of only nanofibers and carbon nanotubes were also constructed. A series of potentiometric measurements as well as electrochemical impedance spectroscopy and chronopotentiometry measuremets were performed in order to compare the obtained sensors and their sensitivity to variable measurement conditions was examined. On the basis of the obtained results, it was found that the modification of the electrodes has a positive effect on their work, in particular on extending the linearity range, lowering the detection limits and improving their potential stability. In the last stage, electrodes were also used to determine the chloride content in water samples.

Presented by

PIETRZAK KAROLINA

Institution

Maria Curie-Sklodowska University, Department of Analytical Chemistry

Keywords

nanocomposite, nanofibers, nanotubes, electrodes, solid contact, chlorides

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Theory for Heterogeneous Water/Oil Separation

Roi Bar-On 1, Ofer Manor 2

Abstract

Oil-polluted water is produced in large quantities in both domestic and industry utilities, which necessitate the development of new functional materials for fast and cheap phase separation. It was shown in laboratory that membranes designed as hydrophilic or hydrophobic may separate oil/water mixtures. The membrane pores possess specific affinity to water or oil, so that to favor the passage of the same phase through the pores and repeal the opposite phase away from the membrane. We employ classical density functional theory (DFT) to elucidate the physical mechanisms governing the phase separation of water/oil emulsion near a membrane surface which possesses specific affinity to oil, at near-equilibrium. We capture emulsion concentration variations near the membrane surface while accounting for the finite volume of oil droplets in the emulsion's bulk and surface forces of molecular origin, i.e., hydrophobic, Van Der Waals (VDW), and electrical double layer (EDL) interactions, between the emulsion droplets. We establish a clear connection between the size of drops, the surface forces between drops in the suspension and the variation in the concentration of droplets next to the membrane. We observe an increase in the concentration of oil droplets next to the lipophilic membrane surface at approximately 10 drop radii. Hence, pores in the membrane will support phase separation if their diameter corresponds to the length scale where the concentration of oil droplets near the solid is appreciably greater than the one in the liquid bulk. Moreover, we observe that the contribution of surface forces to the oil film (wetting the surface) thickness becomes appreciable for droplets smaller than 1 micron. Energy barriers to droplet attachment, which originate in surface forces, appear to increase the dense oil region volume next to the membrane.

Presented by

BAR-ON ROI

Institution

1 Interdisciplinary Graduate Program for Applied Mathematics, Technion - IIT, Haifa, Israel . 2 Department of Chemical Engineering, Technion - IIT, Haifa, Israel

Keywords

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Intraparticle Kinetics Unveil Crowding and Enzyme Distribution Effects on functionality of Cofactor-Dependent Heterogeneous Biocatalysts

Eleftheria Diamanti, Javier Santiago-Arcos, Daniel Grajales-Hernández, Nicolette Czarnievicz, Natalia Comino, Desiré Di Silvio, Aitziber L. Cortajarena and Fernando López-Gallego

Abstract

Understanding the interplay between enzymes and cofactors within the confined space of porous materials rationalizes the fabrication of self-sufficient heterogeneous biocatalysts. Multidimensional kinetic analysis of immobilized enzymes is essential to understand the enzyme functionality at the interface with solid materials. However, spatiotemporal kinetic characterization of heterogeneous biocatalysts on a microscopic level and under operando conditions has been rarely approached. As a case study, we selected self-sufficient heterogeneous biocatalysts where His-tagged cofactor dependent enzymes (dehydrogenases, transaminases and oxidases) are co-immobilized with their corresponding phosphorylated cofactors on porous agarose microbeads coated with cationic polymers. These self-sufficient systems do not require exogenous cofactor addition to function, thus avoiding the extensive use of expensive cofactors. To comprehend the microscopic kinetics and thermodynamics of self-sufficient systems we performed fluorescence recovery after photobleaching measurements, time-lapse fluorescence microscopy and image analytics at both single-particle and intraparticle levels. These studies reveal a thermodynamic equilibrium that rules out the reversible interactions between the adsorbed phosphorylated cofactors and the polycations within the pores of the carriers, enabling the confined cofactors to access the active sites of the immobilized enzymes. This work unveils the relationship between the apparent Michaelis-Menten kinetic parameters and the enzyme density in the confined space, eliciting a negative effect of molecular crowding on the enzyme performance. Finally, through studies at the sub-micrometric level, we demonstrate that the intraparticle apparent enzyme kinetics are significantly affected by the enzyme spatial organization. Hence, multi-scale characterization of immobilized enzymes serves as an instrumental tool to better understand the in-operando functionality of enzymes within confined spaces.

Presented by

DIAMANTI ELEFTHERIA <ediamanti@cicbiomagune.es>

Institution

CIC biomaGUNE

Keywords

protein immobilization, confined kinetics, heterogeneous biocatalysis, polyelectrolytes

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