This first investigation of beer foams using XPS enables a deeper insight than conventional analytics into the composition of beer foams as well as indications of criteria for good beer foam (NIBEM > 300 s; foam index, SKZ > 115). Due to the high sensitivity of this method, even the smallest amounts of residues can be detected in survey spectra. For an initial assessment, the total nitrogen content can be determined comparatively quick and easy, whereby a high value is obviously characteristic of good foams. The N 1s spectra can be employed to determine the quantity and size of proteins which are considered to be foam positive. A high O=C-N/C-NH2 ratio might indicate long peptide chains and seems to be foam positive, as the results reveal. Other groups can also be identified, such as polyphenols, whose influence on the foam is also assessed. Furthermore, the results indicate that appropriate reference measurements could provide a more precise determination of the proteins and influencing factors.

The objective of this study was to investigate the influence of the mashing temperatures on alcohol content and taste of bottom-fermented Pilsner style beers and to ascertain whether these beers exhibit comparable sensorial properties. For this purpose, three beers brewed with three different mashing procedures were compared. The worts produced were sampled during mashing and after boiling, and subsequently analysed for their original gravity, fermentable sugars, and free amino nitrogen. The beers were analysed for their alcohol content, aroma compounds, apparent degree of fermentation, pH value, foam, and bitterness units as well as being evaluated sensorially according to DLG (= "Deutsche Landwirtschafts-Gesellschaft - German Agricultural Society") grading in the categories: odour, purity of taste, body, carbonation, quality of bitterness. Overall it was shown, that the isothermal mashing procedure yielded less fermentable but more unfermentable sugars than the two more traditional mashing procedures, leading to a comparable original wort of 11.6 degrees P in the final beer and lower alcohol content of 2.8% v/v in comparison to the more traditional mashing procedures ("high-short" and "simplified high-short" mashing procedure) with original worts of 12.1 degrees P and alcohol contents of 4.5% v/v and 5.0% v/v, respectively. The DLG-rating showed that the beers derived from the different mashing procedures were all classified similarly with scores above 4.5 on average (out of 5.0) in all categories with no significant differences.

The electrodeposition of Zn films from a deep eutectic solvent (DES) of ZnCl2 and formamide and its mixture with water was studied. From spectroscopic analyses it was observed that water up to 30 v/v% does not change the Zn coordination in the electrolyte after which significant change in the coordination was observed. Electrochemical studies showed that with increase in water concentration in the DES, higher deposition/stripping current was achieved which was related to lowering of viscosity. The Zn deposit morphology changed significantly with water concentration. At low concentrations of water (up to 20 v/v%), porous Zn nanoplates formed whereas the morphology changed to a dense hexagonal structure on increasing the water concentration. X-ray diffraction results confirmed that at low water concentrations (up to 20 v/v%) Zn-Cu alloy formed. Above 20 v/v% water concentration in the DES, Zn peaks evolved with Zn-Cu alloy forming a shoulder. Based on the electrochemical and spectroscopic studies, it appears that 20–30 v/v% water is the critical region wherein significant changes occur from a DES rich region to a water-rich region.

Tantalum is a metal whose properties enable it to be used in a wide range of technological applications. In the present work, the underlying electrochemical processes of tantalum species in ionic liquids (ILs) are investigated using in situ X-ray photoelectron spectroscopy (XPS) in ultra-high vacuum. For this purpose electrochemical deposition of tantalum on a gold wire from 0.1 mol/L TaF 5 in a 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([Py 1,4 ]TFSI) electrolyte was studied by in situ electrochemical XPS. The cyclic voltammogram shows two reduction peaks and one oxidation peak, indicating a complex electrochemical behaviour. The electrochemical in situ XPS gives evidence of a reduction reaction, although no metallic tantalum could be detected on the gold wire. In order to investigate the reactivity of tantalum in more detail, thin IL films were prepared on tantalum by physical vapor deposition and these were examined by XPS. Decomposition reactions were observed with the formation of subhalides, oxyfluorides, or tantalum sulfides, showing the decomposition of the ionic liquid. The decomposition products indicate the splitting of the C-F bond of the TFSI anion.

The processes at the interface between ionic liquids (ILs) and metals are a key factor for understanding especially in electrochemical deposition, nanoscale tribology applications and batteries. In the present work, the interfaces of 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Py1,4]TFSI) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm]TFSI) and platinum and aluminum were investigated by depositing thin IL films and studying them with X-ray photoelectron spectroscopy (XPS) in ultrahigh vacuum. It is found that there is no evidence of a decomposition reaction of either IL on platinum; however, the imidazolium cation of [EMIm]TFSI shows a strong interaction with the surface in the monolayer regime. In contrast, [Py1,4]TFSI and [EMIm]TFSI show massive decomposition on the aluminum surface without applying any electrochemical potential. The spectra for the [TFSI]− anion components show cleavage of C-F or N-S bonds in both cases. Both cleavage of a single fluorine atom and complete cleavage were observed, leading to further decomposition reactions of the anion. Consequently, new components such as AlOOH, Al(OH)3, Al2S3, Al2(SO4)3 and AlF3 appear at the interface. In addition, there is also evidence of decomposition of the cation by the splitting off hydrogen atoms or parts of the alkyl chain in both ILs.

The speciation of Cr, Zn and Sn in AlCl3/1-ethyl-3-methylimidazolium chloride containing CrCl2, ZnCl2 and SnCl2, respectively, has been studied by cyclic voltammetry (CV), Raman spectroscopy and density functional theory (DFT) calculations. Addition of the respective metal salt causes the current waves in the CV to decrease, indicating a reaction of the metal salts with Al2Cl7 −. Compared to the neat electrolyte, the Raman peaks of Al2Cl7 − decrease while the AlCl4 − peak increases in intensity, broadens and shifts towards lower wavenumbers. Calculated wavenumbers of metal complexes [Me(AlCl4)3]− reflect these observations. DFT calculations of the Gibbs free energies of formation, solvation and reaction support the formation of the proposed complexes. The central ions are coordinated by three bidentate AlCl4 − ligands that are arranged planar–trigonally. Due to the occupied Sn–5s orbital, repulsive forces cause a trigonal–pyramidal geometry in case of the Sn complex. Based on the similarities in the experimental observations and the orbital configuration of Zn2+ compared to Cr2+, the spontaneous formation of the species [Cr(AlCl4)3]− can be assumed.

Antimony nanowires have been synthesized by template-free electrodeposition at room temperature from the ionic liquid (IL) 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Py1,4]TFSI) containing 0.5 mol/L SbCl3. The nanowires are shown to have a diameter of ~ 50 nm and a length of ~ 10 µm. Sb nanowires can only be obtained by a two-step electrochemical process, requiring first a cyclic voltammetry step followed by the electrodeposition step. In situ XPS is employed to investigate the speciation formed during the electrochemical reduction process. The results reveal that the XPS core level peaks of the IL and of SbCl3 components shift their binding energies towards higher values accordingly with the applied negative cell voltage. Additional peaks at lower binding energies than those of Sb3+/IL at the OCP can be attributed to the adsorption of reduced Sb species. The formed species together with the IL solvation layers play an important role in the formation of Sb nanowires.

The basic step in beer production is mashing, during which insoluble starch chains, and to a lesser extent cell walls and proteins are broken down by enzymatic hydrolysis. Since the beginning of the modern brewing process there have been empirical studies into the optimum effective temperatures of the corresponding enzymes, and mashing has been carried out accordingly. The resulting resting temperatures of proteolysis, cytolysis and amylolysis with the maltose and saccharification rest, are now rarely changed, only being adapted to the properties of the raw materials used to a limited extent. New varieties of barley and other raw materials used in breweries, as well as modern processes in malting plants, ensure better enzyme potential and optimized malt gelatinization temperatures. The aim of this paper is to determine enzyme activity in barley malt during mashing. For this purpose, isothermal mashing was used, i.e., a mashing process with a constant resting temperature over the entire mashing period. The obtained worts were analyzed for the attributes of extract, final attenuation, β-glucan, total nitrogen, free amino nitrogen, viscosity, and pH as well as sugar composition and individual amino acids. The change in these attributes indicates the enzyme activity of the malt.

In this article, nanowire and macroporous films of CuSn alloy were made by a template-assisted electrodeposition process from the ionic liquid 1-ethyl-3-methylimidazolium dicyanamide ([EMIm]DCA) containing CuCl2 and SnCl2. Polycarbonate membranes were used as templates for the nanowire synthesis. One side of the template was sputtered with a gold thin layer so that it can be used as a working electrode. In the case of CuSn macroporous structures, polystyrene (PS) spheres with an average diameter of 600 nm were applied on gold substrates. The electrodeposited films were characterized by SEM/EDX and XRD giving insight into the morphology and composition, respectively. The SEM results reveal that well-ordered CuSn 2D or 3D macroporous structure can be formed. Furthermore, freestanding CuSn nanowires with an average length of about 7 µm and an average diameter of 100 nm were synthesized as well.

Garnet solid‐state electrolytes are promising for lithium metal batteries in terms of safety and stability. However, their rigid and brittle nature under humid air increase the interfacial resistance at the electrode/electrolyte interfaces. Herein, the ionic liquid (IL) 1‐butyl‐1‐methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([Py 1,4 ]TFSI) is employed to dissolve poly(ethylene oxide) (PEO) polymer microstructures that facilitate ion transport through an amorphous rather than a crystalline polymer matrix. The PEO‐IL coatings on Ga doped garnet (LLZO) solid‐state electrolyte can effectively suppress the formation of Li 2 CO 3 passivation layers on the garnet surface. Electrochemical impedance spectroscopy results show that the interfacial resistance of PEO‐IL coated Ga‐LLZO is much lower than that of uncoated Ga‐LLZO. In addition, the surface of PEO‐IL@Ga‐LLZO is flatter and it has a better contact with the Li anode than uncoated Ga‐LLZO. A symmetric cell of Li/PEO‐IL coated solid electrolyte/Li exhibits flat voltage profiles with overpotentials of less than 15 mV and shows a stable lithium plating/stripping process. A solid‐state battery based on PEO‐IL@Ga‐LLZO solid electrolyte combined with lithium metal anode and LiFePO 4 (LFP) cathode delivers a specific capacity of ≈120 mAh g −1 with a Coulombic efficiency greater than 96% at 10 mA g (LFP) −1 .

Non-alcoholic beers have seen steady growth in recent years and are attracting customer interest. At the same time, consumer demand for non-alcoholic beers is rising. While wort-like flavors are often criticized in beer and also regarded as off-flavors, there is growing demand for beer flavor diversification. The latest research results prove that certain non-Saccharomyces yeast species can produce distinctive fruity flavor profiles during wort fermentation. In this study, 15 different yeast strains were evaluated for their suitability to produce novel flavor profiles during fermentation in wort from malt extract while being tested for their ability to produce less than 0.5% (v/v) ethanol. The yeast strains were therefore analyzed for their sugar utilization and were compared with the maltose-negative reference yeast strain Saccharomycodes ludwigii TUM SL17. Following the fermentation experiments, the beers were analyzed for secondary metabolites and ethanol content before being tasted by trained assessors. The results reveal that all 15 yeasts are suitable for the production of non-alcoholic beers based on their sugar utilization. Particularly promising flavors were produced by three yeast strains of the species Cyberlindnera saturnus, which were reminiscent of cool mint sweets, pear, and banana. Two further yeasts of the species Kluyveromyces marxianus and Saccharomycopsis fibuligera also produced a wide range of pleasant fruity flavors. Although the secondary metabolites were mostly below the odor thresholds based on regular alcoholic beers, this study reveals that the thresholds in non-alcoholic beers can be classified as significantly lower.Supplemental data for this article is available online at https://doi.org/10.1080/03610470.2021.2012747 .

The electrochemical behavior and electrodeposition of indium in an electrolyte composed of 0.1 mol/L InCl3 in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([Py1,4]TFSI) on a gold electrode were investigated. The cyclic voltammogram revealed several reduction and oxidation peaks, indicating a complex electrochemical behavior. In the cathodic regime, with the formation of an In-Au alloy, the reduction of In(III) to In(I) and of In(I) to In(0) takes place. In situ electrochemical X-ray photoelectron spectroscopy (XPS) was employed to investigate the reduction process by monitoring the oxidation states of the components during the cathodic polarization of 0.1 mol/L InCl3/[Py1,4]TFSI on a gold working electrode under ultra-high vacuum (UHV) conditions. The core electron binding energies of the IL components (C 1s, O 1s, F 1s, N 1s, and S 2p) shift almost linearly to more negative values as a function of the applied cell voltage. At −2.0 V versus Pt-quasi reference, In(I) was identified as the intermediate species during the reduction process. In the anodic regime, a strong increase in the pressure in the XPS chamber was recorded at a cell voltage of more than −0.5 V versus Pt quasi reference, which indicated, in addition to the oxidation reactions of In species, that the oxidation of Cl− occurs. Ex situ XPS and XRD results revealed the formation of metallic In and of an In-Au alloy.

Copper-iron alloys were produced at room temperature by means of electrodeposition of iron on a copper substrate in an ionic liquid (1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate [Py-1,Py-4]TfO). Samples with different electrodeposition times were studied using mechanical spectroscopy, scanning electron microscopy, light microscopy and magnetic loops techniques. Independent of the electrodeposition time the electrodeposition process leads to the promotion of a thin layer of iron onto the copper surface without iron diffusion into the substrate. The damping spectra for electrosposited samples in the as-electrodeposited state show the characteristic low and intermediate grain boundary damping peaks from copper as well as the solvent grain boundary damping peak from the electrodeposited iron. Thermal annealing at tempera-tures near 973 K leads to the appearance of Fe particles at the interface between the copper and iron (Cu + alpha-Fe phase) leading to a new damping peak at around 680 K whose driving force is the diffusion of copper atoms around the second phase particles. (C) 2022 Elsevier B.V. All rights reserved.

Zinc-ion batteries (ZIBs) are emerging as cheap and safe alternatives to lithium-ion batteries (LIBs). However, due to the divalent nature of Zn ions, it is a challenge to choose suitable cathode materials for ZIBs. Conductive polymers are regarded as promising materials for zinc storage. However, little has been understood regarding the Zn storage mechanism, thereby making it difficult to rationally modify the polymer to improve its performance and stability. In the present study, polypyrrole (PPy) was electrochemically deposited from aqueous, organic, and ionic liquid electrolytes, and the Zn storage mechanism was investigated in PPy using electrochemical methods, X-ray photoelectron spectroscopy (XPS), and in situ Raman spectroscopy. From in situ Raman spectroscopy, it was observed that Zn storage in PPy electrodeposited from ionic liquid took place by a shrinking and stretching mechanism (structural change), whereas a phase transformation mechanism was observed for PPy electrodeposited from aqueous and organic electrolytes. The change in Zn storage mechanisms led to different initial capacities of PPy deposited from different electrolytes. The initial capacity of PPy deposited from 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([EMIm]TFSI) can achieve 126 mAh g-1 and the PPy deposited from 1-ethyl-3-methylimidazolium trifluoromethylsulfonate ([EMIm]TfO) can reach 90 mAh g-1, which is higher than 75 mAh g-1 for the PPy deposited from acetonitrile and 20 mAh g-1 for the PPy deposited from aqueous solution. Furthermore, XPS results showed that an insignificant amount of zinc was trapped in the PPy deposited from [EMIm]TFSI after 100 charge-discharge cycles. Therefore, the PPy deposited from [EMIm]TFSI showed better cycling stability, after 100 cycles. The different zinc storage mechanisms of PPy from different electrolytes offer possibilities to improve the cycling stability for a Zn/PPy battery by modulating the electrode and electrolyte compositions.

In this paper, we present a constant temperature mashing procedure where grist made of Pilsner malt is mashed-in directly in the temperature regime of alpha-amylase activity, thus omitting all conventional steps, followed by constant temperature mashing at 72 °C. The aim was to investigate an alternative mashing procedure for the production of alcohol-reduced beers. The mashing proceeds with a rapid buildup of sugars and is completed after 120 min at the latest, giving an iodine normal and clear wort. However, the distribution of the different sugars in the worts is strongly altered, in comparison to a more classical mashing procedure. The free amino nitrogen (FAN) concentration is sufficient for vivid fermentation with the bottom fermenting yeast Saccharomyces pastorianus TUM 34/70. The lag phase and initial fermentation performance of this yeast strain are comparable for conventionally and isothermally (72 °C) mashed wort. Under the given conditions the fermentation of the isothermally (72 °C) made wort is finished after 6 days whereas a conventional wort needs 4–5 days more to be completed. The alcohol concentration is remarkably reduced by isothermal mashing leading to roughly 3.4 vol.-% with an original gravity of 11°P whereas with a conventional mashing procedure 4.4 vol.-% are obtained for the same original gravity. In both cases the concentrations of the fermentation by-products are comparable. A preliminary comparison of taste and foam stability did not show striking differences. Constant temperature mashing at 72 °C is a simple way to reduce the alcohol content of beer enriching it at the same time with non-fermentable sugars.

Biodegradable Zn ion batteries have been developed with lignin composite cathodes which can also generate in situ energy by lignin electrocatalytic reaction.

Silicon and germanium are considered as very promising anode materials for lithium-ion batteries due to their high capacities. Understanding the lithiation mechanisms of Si and Ge is important to overcome problems, such as volume expansion, with such materials. In this paper, the changes in the chemical state and the local structure of single-crystalline Si(111) and Ge(111) during the lithiation process on an atomic scale were studied by X-ray photoelectron spectroscopy (XPS). Remarkable differences in the lithiation process between Si(111) and Ge(111) were observed. Two Si 2p peaks in the XPS were observed during the lithiation of Si(111), which can be assigned to the elemental Si 2p and LixSi alloying Si 2p. In contrast, Ge(111) shows one peak in the Ge 3d regime and the peak gradually reduces in intensity and shifts to lower binding energy upon lithiation. Our results also indicate that similar to SiLi3.0 was formed at the surface and metallic Li was more likely to accumulate on the surface of Si(111), even though elemental Si was still available. Nevertheless, Ge(111) shows a homogeneous phase upon lithiation, and different intermediate phases, such as GeLi0.9, GeLi1.5, GeLi3.6, are present with the increase in Li. We expect that our understanding of the lithiation process could contribute to the development of the next-generation high-performance Si- and Ge-based anodes.

In this paper, the structure of the LiFSI-[Py-1,Py-4]FSI interface on Au(111) was investigated using in situ atomic force microscopy and cyclic voltammetry. Raman and IR vibrational spectroscopy was applied to evaluate the coordination of Li+ ions with the FSI- anion. It was found that [Li(FSI)(3)](2-) species are present in the solutions. The solvation layer number and the forces decrease at higher concentration of Li+ ions. Therefore, the driving force, which is required for the [Li(FSI)(3)](2-) species to pass through the solvation layer to reach the electrode surface, is lowered. This increases the onset potentials of the SEI layer formation and lithium underpotential deposition (Li-UPD) at high Li+ concentrations. It was found that the onset potentials are -0.8, -0.7, -0.6, and -0.4 V for the Li-UPD and -2.0, -1.6, -1.4, and -1.3 V for the SEI layer formation, vs the Pt-(quasi)reference electrode, corresponding to Li+ concentrations of 0.1, 0.25, 0.5, and 1 M, respectively.

In this paper, Sn-NiO films for a superior electrochromic performance were prepared by a simple one-step magnetron sputtering process. The amount of Sn in the Sn-NiO films was controlled by adjusting the sputtering power of the SnO2 target. The modification of the microstructure of the NiO film by Sn4+ ions refined the grain size, enlarged the electrochemically active surface and promoted the diffusion of lithium ions, thereby enhancing the electrochromic performances of a NiO film. Compared to pure NiO, the Sn-Ni0 film prepared at a 10 W sputtering power of SnO2 target obtained outstanding electrochromic performances, including large transmittance modulation (65.1%), high coloration efficiency (39.3 cm 2 C-1), fast switching speed (1.3 s and 1.4 s) and good cycling durability at a wavelength of 550 nm. Besides, an optimized Sn-NiO film was used as an anodic electrochromic layer to prepare inorganic all-solid-state electrochromic device (ECD) and the ECD displayed excellent electrochromic performance. The strategy of preparing NiO modified by Sn4+ ions presents an innovative direction to obtain high-performance electrochromic materials for energy-saving smart windows. (C) 2020 Elsevier Ltd. All rights reserved.

Herein, we report the coating of nanostructured germanium using a polypyrrole (PPy) polymer coat as a composite anode material for the fabrication of lithium-ion batteries. The Ge/PPy composites were synthesized following the direct electrochemical deposition method in an ionic liquid (IL). The results revealed that the coating of PPy on Ge helped realize stable battery cycling and reversible capacities, which were not observed in uncoated Ge. The PPy layers could effectively inhibit side reactions between the electrode and electrolyte. The composition of the solid electrolyte interphase (SEI) formed after lithiation/delithiation cycles were analyzed using the X-ray photoelectron spectroscopy (XPS). Compact SEI layers consisted of decomposed TFSI− anion products such as LiF, Li2S, Li2NS2O4, and Li2CO3 at the Ge-PPy/IL interphase. In contrast, thick SEI layers consisted of not only decomposed TFSI− anion and [Py1,4]+ cation products but also chemically or physically adsorbed IL compounds at the Ge/IL interphase. In addition, the PPy coating could effectively inhibit Ge oxidation, resulting in improved battery capacity.