Influence of solvent vapour on phase separation process in a binary polymer blend

Cienkie warstwy mieszanin polimerowych są szeroko stosowane w sektorze elektroniki plastikowej. Na specjalne wyróżnienie zasługują tutaj organiczne ogniwa fotowoltaiczne III generacji, których głównym elementem jest warstwa aktywna, będąca mieszaniną dwóch półprzewodników organicznych. Istotnym zjawiskiem warunkującym wydajność takich urządzeń jest proces separacji fazowej zachodzący w binarnej mieszaninie polimerowej podczas jej formowania. Zrozumienie tego fenomenu, a także możliwość jego kontrolowania pozwoliłaby produkować ogniwa o większej wydajności. W tym celu przeprowadzono badania, mające określić jak obecność par wybranych rozpuszczalników wpływa na proces separacji faz, przebiegający w warstwie mieszaniny PC70BM:PCDTBT w trakcie jej tworzenia metodą spin-coatingu. Topografię powierzchni przygotowanych próbek badano przy użyciu mikroskopu sił atomowych, natomiast ich strukturę wewnętrzną poprzez profilowanie głębokościowe z wykorzystaniem spektrometrii mas jonów wtórnych. Stworzono także działające ogniwa fotowoltaiczne, bazujące na modyfikowanych warstwach PC70BM:PCDTBT. Zebrane wyniki potwierdzają, że obecność par wybranych rozpuszczalników w komorze spin-coatera w znaczący sposób wpływa na proces separacji faz występujący w badanych warstwach, czego efektem jest zmiana ich morfologii w stosunku do referencji.Thin films of polymer blends are widely used in the plastic electronics. Organic photovoltaic cells of the third generation deserve a special mention here. The main element of which is the active layer, composed of two types of organic semiconductors. An important phenomenon that determines the efficiency of such devices is the phase separation process taking place in the binary polymer blend during its formation. Understanding this phenomenon, as well as being able to control it, would allow the production of cells of higher efficiency. For this purpose, studies were carried out to determine how the presence of selected solvent vapors influences the phase separation process in the layer of the PC70BM:PCDTBT mixture during its formation during the spin-coating. The surface topography of the prepared samples was investigated by using an atomic force microscope, while their internal structure was examined by depth profiling with the use of secondary ion mass spectrometry. Working photovoltaic cells were also created, based on modified PC70BM:PCDTBT layers. The collected results confirm that the presence of selected solvent vapors in the spin-coater chamber significantly affects the phase separation process occurring in the tested films, which results in a change of their morphology in relation to the reference

Engineering thin polymer films surface using silanes

Cienkie warstwy organiczne na bazie polimerów ze względu na swoje unikalne właściwości fizykochemiczne znajdują coraz większe zastosowanie w technologii oraz przemyśle. Spośród licznych urządzeń, w których są one wykorzystywane można wymienić organiczne diody elektroluminescencyjne, ogniwa fotowoltaiczne czy tranzystory polowe. Możliwość kontrolowania wybranych właściwości takich warstw m.in.: swobodnej energii powierzchniowej, przewodnictwa, czy pracy wyjścia daje ogromne możliwości aplikacyjne, szczególnie w dynamicznie rozwijającej się branży elektroniki plastikowej i organicznej.Cienkie warstwy poli(3,4-etylenodioksytiofenu):(sulfonianu polistyrenu) (PEDOT:PSS) wytworzone metodą spin-coatingu na podłożu krzemowym, wystawiono na działanie par molekuł trimetoksy (3,3,3-trifluoropropylo) silanu (3FS) rozpuszczonych w toluenie. Porównanie widm mas otrzymanych metodą spektrometrii mas jonów wtórnych (SIMS) dla czystych i modyfikowanych próbek wykazało, że molekuły silanów adsorbują do powierzchni PEDOT:PSS. Obecność tych molekuł, posiadających trwały moment dipolowy znacząco wpływa na wartość swobodniej energii powierzchniowej modyfikowanych warstw, co zostało udowodnione na podstawie pomiarów kąta zwilżania. Podczas prowadzonych badań udało się w kontrolowany sposób zmieniać wartość swobodnej energii powierzchniowej w zależności od czasu ekspozycji warstwy na pary roztworu silanów w zakresie od 65 do 45 mJ/m2. Dodatkowo wykorzystanie mikroskopu sił atomowych (AFM) do zobrazowania powierzchni cienkich warstw mieszaniny poli(3-butylotiofenu):deuterowanego poli(4-bromostyrenu) (P3BT:dPBrS) rozlewanych na modyfikowanym podłożu PEDOT:PSS pozwoliło dowieść, że morfologia takiej warstwy jest silnie skorelowana ze stopniem modyfikacji tego podłoża.Thin polymer films are widely used in many organic electronic devices e.g. in light-emitting diodes, field effect transistors and organic photovoltaic devices. Variety of selected physical and chemical properties, like Surface Free energy (SFE), conduction or the work function gives them large application possibilities, especially in dynamically developing technology such as plastic and organic electronics. In presented work, I have shown a method to control surface free energy of poly(3,4-ethylenedioxythiophene):(polystyrene sulfonate) (PEDOT:PSS) thin films by evaporation trimethoxy(3,3,3-trifluoropropyl)silane (3FS). Value of SFE can be controlled via time of evaporation of 3FS molecules, which was proven based on the measurement of the contact angle. The maximum achieved change of SFE was 22.5 mJ/m2 referred to the unmodified film. Additionally I presented the influence of the modification on the morphology of solution-cast model poly(3-butylthiophene):poly(4-bromostyrene) (P3BT:dPBrS) thin films

Dual-enhancement and dual-tag design for SERS-based sandwich immunoassays : evaluation of a metal–metal effect in 3D architecture

The design of a sandwich-type SERS immunoassay (surface-enhanced Raman spectroscopy) is demonstrated operating in dual surface enhancement and dual-tag paradigm. The capture and detection antibodies are linked to two SERS-active substrates and form together the three-dimensional (3D) structure after specific binding to interleukin 6. A variety of metal combinations is tested (Au–Ag, Au–Au, and Ag–Ag), but an enhanced electromagnetic field is generated only due to coupling of Ag and Au nanoparticles with an Au hexagonal nanoarray. The amplified in that way Raman signals improve the limit of detection over 3 times in comparison to the assay with only one SERS-active substrate. It is also shown that the proper readout of the true-positive signal can be achieved in assays with two Raman tags, and this approach also improves LOD. For the optimal combination of the metal–metal junction and Raman tags, a linear relationship between the Raman signal and the concentration of IL-6 is obtained in the range 0–1000 pg⋅mL(−1)with LOD of 25.2 pg mL(−1)and RSD < 10%. The presented proof-of-concept of the SERS immunoassay with the dual-enhancement and dual-tag opens additional opportunities for engineering reliable SERS biosensing. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00604-021-05125-0

Plastic waste depolymerization as a source of energetic heating oils

In the past years there has been an increase in production and consumption of plastics, which are widely used in many areas of life. Waste generated from this material are a challenge for the whole of society, regardless of awareness of sustainable development and its technological progress. Still the method of disposal of plastic waste are focused mainly on their storage and incineration, not using energy contained there. In this paper technology for plastic waste depolymerization with characteristics of fuel oil resulting in the process, as an alternative to traditional energy carriers such as: coal, fine coal or coke used in households will be presented. Oil has a high calorific value and no doubt could replace traditional solutions which use conventional energy sources. Furthermore, the fuel resulting from this process is sulfur-free and chemically pure. The paper presents the installation for plastics waste depolymerization used in selected Polish Institute of Plastics Processing, along with the ability to use the main thermocatalytic transformation product

Plastic waste depolymerization as a source of energetic heating oils

In the past years there has been an increase in production and consumption of plastics, which are widely used in many areas of life. Waste generated from this material are a challenge for the whole of society, regardless of awareness of sustainable development and its technological progress. Still the method of disposal of plastic waste are focused mainly on their storage and incineration, not using energy contained there. In this paper technology for plastic waste depolymerization with characteristics of fuel oil resulting in the process, as an alternative to traditional energy carriers such as: coal, fine coal or coke used in households will be presented. Oil has a high calorific value and no doubt could replace traditional solutions which use conventional energy sources. Furthermore, the fuel resulting from this process is sulfur-free and chemically pure. The paper presents the installation for plastics waste depolymerization used in selected Polish Institute of Plastics Processing, along with the ability to use the main thermocatalytic transformation product

Photoelectrochemical performance of nanotubular Fe2O3−TiO2Fe_2O_3-TiO_2 electrodes under solar radiation

Fe(2)O(3)–TiO(2) materials were obtained by the cathodic electrochemical deposition of Fe on anodic TiO(2) at different deposition times (5–180 s), followed by annealing at 450 °C. The effect of the hematite content on the photoelectrochemical (PEC) activity of the received materials was studied. The synthesized electrodes were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, diffuse reflectance spectroscopy (DRS), Mott–Schottky analysis, and PEC measurements. It was shown that the amount of deposited iron (ca. 0.5 at.%–30 at.%) and, consequently, hematite after a final annealing increased with the extension of deposition time and directly affected the semiconducting properties of the hybrid material. It was observed that the flat band potential shifted towards more positive values, facilitating photoelectrochemical water oxidation. In addition, the optical band gap decreased from 3.18 eV to 2.77 eV, which resulted in enhanced PEC visible-light response. Moreover, the Fe(2)O(3)–TiO(2) electrodes were sensitive to the addition of glucose, which indicates that such materials may be considered as potential PEC sensors for the detection of glucose