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The study aimed at evaluation of the rheological properties of aqueous suspensions of SiC stabilized with either TMAH (tetramethyloammonium hydroxide) or NaOH in the amount of a given dispersant in the range of 0–1.0 wt% as calculated on the dry mass of SiC powder. The optimal amount of the dispersants was finally evaluated at 0.4–0.6 wt %, based on the results of rheological studies (flow curves and viscosity curves) and the sedimentation rate, which corresponded to the pH of the suspension within the range of 9.5–10.5. The amount of the dispersant here did not depend on the solid volume fraction in the suspension, but rather, according to the zeta potential measurement results, the pH range guaranteed the formation of a stable suspension. This effect allowed to propose a dispersant mechanism for stabilizing the suspension. The maximum amount of silicate anions formed, accordingly, in the pH range of 9.5–10.5 on the surface of SiC particles, which in turn could be able to adsorb Na+ or TMA+ cations and thus increase the thickness of the Stern layer, increasing electrostatic repulsion between the SiC particles and improving the stabilization of suspensions and their rheological properties. However, the increase in suspension pH deteriorated their stabilization – most likely due to the occurrence of polymerization of amorphous silica and the presence of additional cations in water increasing its ionic strength. These suggestions were confirmed by the results of XPS analysis of the chemical state of SiC particle surfaces.

International audience; The catalytic decomposition of N2O was studied over a series of calcined Mn(Fe)CoAl hydrotalcite-like compounds. The precursors were prepared by coprecipitation and characterized by XRD and TGA. The mixed metal oxides derived after calcination at 600 °C were characterized by XRD, N2 adsorption, H2-TPR and XPS. Moreover, in situ XAFS measurements over selected mixed metal oxides were performed. Such investigations under relevant reaction conditions are rare, while a comprehensive understanding of the involved active species may facilitate a knowledge-based catalyst optimization. The activity of the CoAlOx (Co/Al = 3/1, mol.%) catalyst varied depending on the loading of Mn or Fe (0.0575, 0.0821, 0.1150, 0.1725, 0.2300, mol.%). In the investigated series, Mn0.1725Co3AlOx reached the highest activity with T50 of about 305 and 376 °C under N2O/N2 and N2O,NO,O2/N2 feed, respectively. In situ X-ray absorption experiments over Mn0.1725Co3AlOx suggested that MnxCoyO4 spinels undergo reduction to CoO and MnO upon heating up to 600 °C in He. Under N2O/He conditions, initial reoxidation of cobalt species began at 350 °C. The lower activity obtained for Fe0.1725Co3AlOx is explained by the fact that the majority of Fe was not incorporated into the Co3O4 structure but instead formed less reactive iron oxide clusters.

Usage of CNTs as matrix modifiers during fabrication of CNFs from the electrospun polymer precursor is an interesting approach to obtain composite materials with a new set of properties. However, the progress in this field is hindered by the lack of consistency of the CNTs used in the studies and sometimes insufficient materials characterization. In this study, two types of CNTs were at first characterized to reveal their chemical composition and morphology (by TEM and XPS) and then used as matrix additives in the process of electrospinning. The outcome product was evaluated for morphology (SEM), chemical composition (XPS, FTIR), course of thermal transition (STA-FTIR) and level of structural arrangement (TEM combined with SAED) to answer the question how do CNTs interact with polymer matrix and how it impacts the process of thermal transition and properties of the as-received carbon nanofibers. Highly oxidized and short CNTs were found to increase the structural arrangement, catalyzing the thermal transition, while thin and long CNTs, with low amount of oxygen, entrap the nitrogen atoms, yielding nitrogen-doped CNFs that might be suggested as high-performance oxygen reduction reaction catalysts.

Titanium dioxide in the form of anatase is known to be a good photocatalyser but catalytic properties strongly depend on TiO2 grain size, morphology and surface area of thin film. The aim of this study was to evaluate influence of carbon nanotube additive on photocatalitic properties of TiO2.Titanium dioxide/multiwalled carbon nanotubes (MWCNT) nanocomposites were prepared by sol-gel method in the form of a thin layer on glass substrates. Samples were characterized by X-ray diffraction (XRD) and Grazing Incidence Diffraction (GID), Raman, FTIR and UV-VIS spectroscopy, as well as scanning electron microscopy (SEM). The photocatalytic activity of prepared films was evaluated by the detection of changes in the UV-VIS spectra after the discoloration of Reactive Black V pigment - water solution. It was found that the crystalline TiO2 is composed of anatase phase only. Presence of MWCNTs in the composite increases the size of TiO2 particles. Additive of nanotubes into the TiO2 resulted in an increase in photocatalytic activity in both the UV and visible range by 10 and 50% respectively compare to undoped TiO2. Furthermore, carbon nanotubes lead to better dye adsorption on the surface. Additionally significant reduction in the contact angle, approximately 50% (compare to pure TiO2) was also observed. The obtained results suggest that the TiO2/carbon nanotubes composite material can be activated by light from visible range.

XRD, BET, H2-TPR, UV–vis-DRS, XPS and XAFS were used to characterize a series of Ag and/or Cu – Ag (1–5%), Cu (10–15%) or Ag-Cu (1–1, 1–10, 1.5–10, 5–5% of metal) – supported on γ-Al2O3. Correlation between physicochemical properties, catalytic activity and selectivity in NH3-SCO were thoroughly investigated. Silver species mainly in the form of Ag2O on the Ag/Al2O3 catalysts led to enhanced activity together with drop in N2 selectivity with increasing silver loading up to 5%. A mixture of CuO and CuAl2O4 formed on the Cu/Al2O3 catalysts. Easily reducible highly dispersed CuOx promoted the activity of the catalysts, while bulk CuOx and CuAl2O4 decreased N2 selectivity up to 500 °C. The activity of all Cu-containing materials was inferior to Ag-containing ones. Thus, the gap between the high conversion temperature over Cu/Al2O3 and low N2 selectivity over Ag/Al2O3 was bridged by applying the Ag-Cu/Al2O3 catalysts, with the optimum loading of 1.5 and 10 wt.% for silver and copper, respectively. NH3-TPD, NH3-TPSR and in situ FTIR were used to determine the in situ selective catalytic reduction (i-SCR) mechanism over 1.5% Ag/Al2O3, 10% Cu/Al2O3 and 1.5% Ag-10% Cu/Al2O3 respectively. The i-SCR mechanism involved the partial oxidation of NH3 into NOx species, along with adsorbed NOx species interacting with adsorbed ammonia (NHx species) and being reduced to reaction products.

The work was focused on the spectroscopic examination of zirconia-based layers deposited on metallic substrates. Metallic biomaterials belong to the group of well-known and most widely applied materials in medicine. They might be characterized by the easiness of formation and good mechanical properties. However, the surface properties of the material need to be strictly controlled to prevent corrosion processes and ensure biocompatibility. One of the modifications leading to improvement of the properties important in terms of considering the material for biomedical applications was the fabrication of ceramic layers on the surface. Presented zirconia-based layers doped with calcium and hydroxyapatite were obtained using the sol-gel method and deposited on the metallic (titanium and steel) surface with the use of dip-coating technique and electrophoretic deposition (EPD) method. Obtained layers were examined with multiple spectroscopic and microscopic methods such as Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Also the surface properties – wettability and surface free energy (SFE) – were measured. Bioactivity of the obtained layers was evaluated by the in vitro test in simulated body fluid (SBF) - the so-called Kokubo test.

Ag-, Ce- and Ga-promoted Cu–Mg–Al hydrotalcite derived mixed metal oxides were obtained by standard coprecipitation, followed by calcination. The obtained Ag(Ce, Ga)–Cu–Mg–Al–O x mixed metal oxides were characterized with respect to their crystalline structure (XRD, TEM), texture (BET), surface acidity (NH 3 -TPD), redox properties (H 2 -TPR), chemical surface composition (XPS), and tested in the selective catalytic oxidation of ammonia into nitrogen and water vapour (NH 3 -SCO). The loading of Ag y -, Ce y -, or Ga y –Cu 5 –Mg 66− y –Al 29 ( y = 0–1) had a clear effect on the catalytic performances. For materials with low metal loadings ( y ≤ 0.25), the redox properties determined the catalytic performances in NH 3 -SCO. The formation of easily reducible CuO x played a crucial role for enhanced catalytic activity at lower temperatures, with a drop in the selectivity to N 2 at higher temperatures. Higher metal loading ( y ≥ 0.5) led to the formation of surface and bulk copper oxide species, and other aggregated metal oxide phases, which enhanced the catalytic activity for Ag–Cu–Mg–Al–O x , and diminished activity for Ce(Ga)–Cu–Mg–Al–O x .

The paper studies an influence of Ga2O3, PbO and BaF2 on the thermal stability of tellurite glass and their properties: thermal expansion coefficient, transmittance and refractive index. Three series of gallium-tellurite glass were prepared: I – (100 − x)TeO2·xGa2O3 where x = 5, 10, 15 and 25 mol%, II – (85 − x)TeO2·15Ga2O3·xBaF2 where x = 1, 3, 6, 11 mol%, III – (90 − x)TeO2·10Ga2O3·xPbO where x = 0, 5, 10 mol%. It was confirmed that stable gallium-tellurite glass can be produced without applying super-cooling methods in the range 5–15 mol% Ga2O3. Ga2O3 acts only as a stabilizer of the TeO2 glassy network when its content not exceed 15 mol%. As shown this effect is connected with the change in crystallization ability of orthorhombic and tetragonal forms of TeO2. It was found that the latter is preferable when Ga2O3 content increases. The increase of the Ga2O3 content over 20 mol% induces its spontaneous crystallization. Admixture of BaF2 and PbO to the Te2O-Ga2O3 glass diminishes a tendency to the glass crystallization. Tellurite glasses with Ga2O3, PbO and BaF2 show good transmittance in the VIS, NIR and MIR up to 5.5 μm. BaF2 and PbO, unlike Ga2O3, decrease the thermal expansion coefficient of tellurite glass. The change in the refractive index due to the admixtures was presented.

Coating the material of choice with a layer of well-adhered carbon nanotubes is a subject of interest in many fields of materials science and industry. Electrophoretic deposition is one of the methods to handle this challenging task. In this process, careful designing of the deposition parameters is crucial in obtaining the product of strictly desired properties. This study was aimed to identify the influence of the diluent on the physicochemical ad electrochemical qualities of the final product. By analyzing the properties of the suspensions being used, we were able to hypothesize on the mechanisms of carbon nanotubes—liquid interactions and their outcome on the thickness, homogeneity, chemical and structural composition and electrical conductivity of the metal substrate covered with a layer of carbon nanotubes. We obtained a materials, composed of metal and a layer of CNTs, with conductivity that is superior to an unmodified metal. This types of materials may find numerous applications in fabrication of novel electronic devices, including the implantable electrodes for biomedicine—as reported in our previous studies, these types of coating are biocompatible.

This work demonstrates the adsorption capacity of carbon micro- (CF) and nanofibrous (CNF) adsorbents differing in specific surface area, fiber diameter and open porosity in the removal of NaCl from water. The effect of the adsorption conditions, i.e. contact time, initial salt concentration, and oxidative surface treatment on the adsorption kinetics and equilibrium salt uptake capacity was investigated. Adsorption experiments were carried out by batch-mode experiment at room temperature. The study showed that activated CNF exhibit high adsorption capacity for NaCl, namely 827.5 mgNaCl/gCNF, and this value is over 40 times higher than that of activated carbon and exceeds the values reported for CNT and GO. The adsorption kinetics followed the pseudo-second-order kinetic model and was largely controlled by the intramolecular diffusion rate. The equilibrium data showed a good correlation with the Langmuir and Freundlich isotherms, which supported the complex interaction of salt with the carbon surface. It was shown that salt ions can be attached to the fibrous surface both by ion-exchange mechanisms and electrostatic interactions. The carbon fibrous adsorbents present a new approach to water desalination through the mechanism of adsorption and continuous crystallization, and may be used for the elaboration of new type membranes for water purification and desalination.

The main objective of this paper is to attempt to determine the structure of free carbon phase in SiOC glasses derived from ladder-like silsesquioxane precursors. The samples were fired in argon flowing atmosphere, in a wide temperature range (200–800° C). Conducted XRD, Raman, MIR spectroscopy research allowed to determine the structure of obtained materials. Combined XPS and Raman studies enabled to establishing the point of formation of free carbon in silicon oxycarbide matrix. Two most popular concepts were confronted with Raman and XPS results of free carbon phase in studied materials. This allowed to conclude that for temperatures below 800 °C carbon is present in a form of graphite domains inside glassy matrix.

Structural changes accompanying stabilization and carbonization processes of the two types of polyacrylonitrile (PAN) nanofiber precursors (pure PAN and PAN with carbon nanotubes) were studied using infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The fibrous membranes were preliminary stabilized in air followed by the two-step carbonization process under nitrogen atmosphere. IR absorption spectra showed that the introduction of a small amount of functionalized multiwall carbon nanotubes (MWCNT) into the PAN precursor has a significant impact on its stabilization process. Raman spectroscopy study showed that the structure of carbon nanofibers containing CNT is distinctly more ordered in comparison to pure carbon nanofibers. Based on the XPS analysis the concentration of heteroatoms and the type and amount of functional groups on the surfaces of both types of nanofibers were determined. The results indicate a high potential of functionalized MWCNT as a pyrolysis modifier of polymer precursor leading to the formation of carbon nanofibers with controlled structure and defined chemical state of the surface.

Lead–gallium glasses, due to the absence of typical glass-forming components, are characterized by an increased tendency to crystallization. Despite this, they are interesting materials due to a shift of IR absorption edge up to 6–7 μm. The paper considers how the SiO2 dopant affects thermal stability and the UV–VIS and IR transmittance of lead-gallium glasses. The base lead-gallium glass (0.75PbO·0.25Ga2O3) was modified by the addition of 5, 10 and 15 mol% SiO2, respectively. DTA/DSC data showed that the glasses are characterized by the multi-stage crystallization, which is changed with the amount of silica doped. The XRD analysis confirmed that: (i) different forms of lead oxide crystallize after heat treatment of the glass, and (ii) the Ga2PbO4 phase is formed at higher temperatures. The silica admixture allowed inserting a few percent of BaF2 into the lead–gallium glass structure. It was found that a transparent glass–ceramic based on the lead-gallium glass with a low phonon barium fluoride phase can be obtained during the thermal treatment. The study of UV–VIS–IR transmittance shows that 10–15 mol% SiO2 in the lead-gallium glasses diminishes the absorption band in the range of 2.6–4 μm due to the presence of hydroxyl groups and simultaneously reduces transmittance in the range of 5–6.5 μm from 10 to 20%. Introduction of SiO2 to the glass results in the increase of transmittance in the shorter wavelength region and the UV-edge shift is observed. It was also confirmed that the BaF2 nanocrystallites exert s no effect on the transmittance of the spectrum analyzed.

In this study the role of PI3K/Akt signaling pathway in arsenic trioxide (ATO)-treated parental Jurkat cells and also in derived ATO-resistant clones grown in the presence of given ATO concentration was investigated. ATO-resistant clones (cultured for 8-12weeks in the presence of 1, 2.5 and 5μM ATO) were characterized by high viability in the presence of ATO but slower growth rate compared to the parental cells. Morphological and functional characterization of derived ATO-resistant clones revealed that they did not differ fundamentally from parental Jurkat cells in terms of cell size, level of GSH, the lysosomal fluorescence or CD95/Fas surface antigen expression. However, a slight increase in the mitochondrial potential (JC-1 staining) was detected in the clones compared to parental Jurkat cells. Side population analysis (Vybrant DyeCycle Violet™ staining) in ATO resistant clones did not indicate any enrichment withcancer stem cells. Akt1/2, AktV or wortmannin inhibitors decreased viability of ATO-resistant clones grown in the presence of ATO, with no effect on ATO-treated parental cells. Flow cytometry analysis showed that ATO decreased the level of p-Akt in ATO-treated parental cells, while the resistant clones exhibited higher levels of p-Akt immunostaining than parental Jurkat cells. Expression analysis of 84 genes involved in the PI3K/Akt pathway revealed that this pathway was predominantly active in ATO-resistant clones. c-JUN seems to play a key role in the induction of cell death in ATO-treated parental Jurkat cells, as dose-dependent strong up-regulation of JUN was specific for the ATO-treated parental Jurkat cells. On the other hand, changes in expression of cyclin D1 (CCND1), insulin receptor substrate 1 (IRS1) and protein kinase C isoforms (PRKCZ,PRKCB and PRKCA) may be responsible for the induction of resistance to ATO. The changes in expression of growth factor receptor-bound protein 10 (GRB10) observed in ATO-resistant clones suggest a possibility of induction of different mechanisms in development of resistance to ATO depending on the drug concentration and thus involvement of different signaling mediators.

Titanium dioxide nanomaterials are extensively used in many applications, also for modification of textile materials. Toxicological assessment of such textile materials is currently seldom performed, mainly because of lack of appropriate guidelines. The aim of the study was to assess cytotoxic and genotoxic potential of commercially available TiO2 and TiO2/Ag NMs in pristine form as well as polypropylene fibers modified with the NMs. Both titania NMs showed a cytotoxic effect on BALB/3T3 clone A31 and V79 fibroblasts after 72 - h exposure. Both NMs induced a weak genotoxic effect in comet assay, with TiO2/Ag being more active. In vitro micronucleus test on human lymphocytes revealed a weak mutagenic effect of both materials after 24 h of exposure. In contrast, no significant increase in micronuclei frequency was observed in the in vitro micronucleus test on V79 fibroblasts. The 24-h extracts prepared from polypropylene fibers modified with TiO2/Ag induced a cytotoxic effect on BALB/3T3 cells which strongly depended on the mode of the fibers manufacturing. The study presents a comprehensive approach to toxicity assessment of textile fibers modified with NMs. Proposed approach may form a good “starting point” for improved future testing strategies.

Glasses of different matrix (phosphate, borate, silicate and lead-silicate) were studied for their optical properties. The effect of Er dopant on transmittance and luminescence properties was presented. The significant “red shift” and “blue shift” of UV edge absorption were discussed based on the changes in the framework of the borate and phosphate glasses, respectively. It was showed that the integral intensity of the two main optical absorption transitions monotonically increases with the order: phosphate 3+ was discussed.

Hybrid glasses based on tetraethoxysilane (TEOS) modified by addition of selected cyclosiloxanes have been prepared by sol–gel method. Octamethylcyclotetrasiloxane (D4) and 2,4,6,8-tetramethyl-2,4,6,8-tetravinylsiloxane (VMC) have been chosen as an organic modifier of the silica matrix. Molar ratio of TEOS to cyclosiloxane varied from 1:0 to 1:0.5. Structure of prepared hybrids has been studied by infrared spectroscopy (FTIR), photoelectron spectroscopy (XPS) and nuclear magnetic resonance spectroscopy (NMR). Optical properties of bulk glasses in the visible range have also been reported.

Hybrid glasses prepared by sol–gel method are considered as promising candidates for corrosion protection coatings. Hybrids based on TEOS (tetraethylorthosilicate)–TEOT (tetraethylorthotitanate)–GLYMO (3-glicydoxypropyltrimethoxysilane) and TEOS–TEOT–MTMS (methyltrimethoxysilane) systems were synthesized by sol–gel method. Structure of the glasses was studied by FTIR, XPS and optical spectroscopy. It was revealed that the titanium is present in tetrahedral and octahedral coordination. High resolution SIMS technique was used to verify homogeneity of the layers.

Hybrid glasses based on tetraethylorthosilicate (TEOS)–trimethoxyoctylsilane (TMOS) and TEOS–tetraethylorthotitanate (TEOT)–trimethoxyoctylsilane systems were prepared by sol–gel technique. Structure of the hybrids was studied by FTIR and XPS spectroscopy. The studies reveal that the titanium is mainly in tetrahedral coordination substituting for silica and acting as a glass former. Some part of titanium is also present in octahedral coordination. Optical properties of hybrid glasses in the visible range strongly depend on amount of organic modifier and higher transparency is observed for glasses having higher content of TMOS.

The results of structural studies of the glasses from Li2O–Bi2O3–PbO system were presented. Infrared spectroscopy (FTIR) and photoelectron spectroscopy (XPS) were applied to determine main structural unites and chemical composition of near-surface region. Glasses from the studied system are build up with lead in tetrahedral coordination and bismuth in octahedral coordination. Structural role of lithium relies on compensation of the electric charge and on separation of lead-reach and bismuth-reach regions preventing crystallization of the glasses. It was shown that the lithium is not present in near-surface regions. The thermal stability of the glasses was determined from DTA measurements. Optical properties in UV–vis region were also presented.

Lithium phosphate glasses with different chemical composition have been studied using infrared absorption spectroscopy (FTIR) and photoelectron spectroscopy (XPS). FTIR and XPS spectra were analyzed to determine the main structural units present in the glass. Absorption bands were identified and assigned to appropriate bond vibrations. It has been shown that analyzed glasses are built up mainly of short chains and rings consisting of metaphosphate structural units – Q2. Some pyro- and orthophosphate units Q1 and Q0, respectively are also present. Photoelectron spectroscopy studies have revealed that titanium exists in two valence states: as Ti3+ and Ti4+. Increasing TiO2 content results in shortening of P–O bonds but leads to elongation of PO bonds in PO4 tetrahedra.

Isotope substitution method was used to identify the Li–O absorption bands in crystalline lithium silicates (2Li 2 O 3 ·SiO 2 , Li 2 O·SiO 2 , Li 2 O·2SiO 2 ) and selected aluminosilicates (β-eucriptite and β-spodumene). Isotopic shift was established after mathematical decomposition of the IR spectra. Absorption bands connected directly with internal, LiO 4 tetrahedron vibrations are observed in the range 460–250 cm −1 . Bending vibrations of Si–O–Li bridges give absorption bands in the range 500–600 cm −1 . The exact position of the bands and their isotopic shifts are given.

MIR spectra of lithium silicates and aluminosilicates were measured and compared with the simulated spectra. Simulation was carried out by mathematical summation of appropriate glass spectra taken in the right proportion. It was shown that the spectra obtained in this way are very similar to the measured spectra. It confirms phase inhomogeneity of studied glasses with short or even medium range of order. Structures of lithium silicate and aluminosilicate glasses consist of structural elements resulting from its composition and position in the field of primary crystallisation. The structure of these elements is very similar to their crystalline analogues with the same chemical composition, but they are much more disordered and do not have translation symmetry.

The scale development on the unmodified and yttrium-implanted Fe19Cr5Al and Fe19Cr5Al0.27Y alloys at 1173 K during oxidation exposures up to 15 min was studied by means of XPS, SEM and EDX. The commercial material Kanthal APM was used as reference. A particular advantage of the XPS method relied on the possibility to distinguish between metallic and oxidized states of the elements. The scale evolution occurred in all cases via the same stages. At the beginning three-layered scales appeared, consisting of the outermost iron oxide, intermediate chromia and innermost alumina. The alumina, being thermodynamically the most stable oxide in this system, successively grew towards the scale/gas interface. Although alumina constituted the majority of scales formed during 15 min exposures, the other oxides were still present in the outermost parts of the scales. The fraction of the iron oxide and chromia in the scale was higher on the yttrium-implanted material than on the other alloys. No remarkable differences were observed regarding this fraction between the yttrium-free unimplanted and yttrium-bearing alloys. Metallic iron and chromium were found for shorter oxidation periods below their oxides. Subsequently, after 15 min exposure, the uniform distribution of the metallic iron and chromium in the scales were observed in all alloys except for the yttrium-implanted one.

The glassy state of matter, in contrast to crystalline solids, is characterized by a lack of long-range order. In the structure of glasses, the bond lengths and bond angles are not fixed. As a consequence the vibrational spectra of glassy sustances exhibit various band shapes. The bands in these spectra are characterized by complex shapes and significant widths resulting in difficulties in the determination of the main spectral parameters, such as the number of bands, their positions and intensities. These difficulties limit the application of vibrational spectroscopy in the study of the structure of glasses. The main goal of the present work is to show that an appropriate procedure of decomposition of the complex bands in the spectra makes it possible to obtain important information on the structure of solid glassy substances. The procedure proposed is based on (a) minimization of the number of bands, and (b) comparison with the spectra of crystalline analogues. The number of components in a complex band and its parameters are found by analysis of the second derivative of the spectrum, using Fourier self-deconvolution as proposed by Griffiths and Pariente (Trends Anal. Chem., 5 (1986) 209). According to the procedure proposed, the spectra of the crystalline and glassy analogues of the following substances were decomposed: SiO2 (silica), K[AlSi2O6] (leucite) and Li(AlSi2O6) (spodumene). This decomposition of the complex bands in the spectra of glassy substances meant that their structures could be more readily deduced. It was shown that as well as the bands corresponding to the crystalline analogues in the spectra of glasses, there are bands responsible for characteristic features of the structure of glasses.