pH adjustment

Leather artifacts in historical collections and archives are often contaminated by physical changes such as soiling, which alter their appearance and readability, and by chemical changes which occur on ageing and give rise to excessive proportion of acids that promote hydrolysis of collagen, eventually leading to gelatinization and loss of mechanical properties. However, both cleaning and pH adjustment of vegetable tanned leather pose a great challenge for conservators, owing to the sensitivity of these materials to the action of solvents, especially water-based formulations and alkaline chemicals. In this study the cleaning of historical leather samples was optimized by confining an oil-in-water (o/w) nanostructured fluid in a highly retentive chemical hydrogel, which allows the controlled release of the cleaning fluid on sensitive surfaces. The chemical gel exhibits optimal viscoelasticity, which facilitates its removal after the application without leaving residues on the object. Nanoparticles of calcium hydroxide and lactate, dispersed in 2-propanol, were used to adjust the pH up to the natural value of leather, preventing too high alkalinity which causes swelling of fibers and denaturation of the collagen. The treated samples were characterized using Scanning Electron Microscopy (FE SEM), controlled environment dynamic mechanical analysis (DMA-RH), and infrared spectroscopy (ATR-FTIR). The analytical assessment validated the use of tools derived from colloid and materials science for the preservation of collagen-based artifacts.

h i g h l i g h t s " Cultivation of C. zofingiensis in dairy wastewater was investigated. " Algal growth rate and composition were different under CO 2 and HAc regulations. " It's feasible to cultivate C. zofingiensis in outdoor ponds in winter, South China.

h i g h l i g h t s " Cultivation of C. zofingiensis in dairy wastewater was investigated. " Algal growth rate and composition were different under CO 2 and HAc regulations. " It's feasible to cultivate C. zofingiensis in outdoor ponds in winter, South China.

This paper describes the application of Attenuated TotalReflection Fourier Transform Infra-red Spectroscopy (ATR-FTIR) together with Scanning Probe Microscopy (atomicforce microscopy and micro-thermal analysis) on acceleratedaged and archival parchment samples. Damageassessment by ATR-FTIR of collagen, the main constituentof parchment, was based on spectral changes in collagen,in particular within the amide I carbonyl stretching region.This is known to be sensitive to changes in the triple helicalstructure of collagen. Damage assessment by AtomicForce Microscopy (AFM) was based on changes in the periodicD spacing of the collagen fibrils. Measurements madeon the same samples showed that in damaged samplesthere was partial and eventually complete loss in the Dspacingof the collagen fibrils. This was particularly evidentin accelerated aged samples subjected to pollutantgas (SO2). Micro-thermal analysis (micro-TA) of the sameregions of parchment showed differences in the thermalbehaviou...

The aim of this paper is to describe how atomic force microscopy (AFM) has been used to assess damage in parchment at the collagen fibril level on exposure to relative humidity (RH) fluctuations at a given temperature, and to pollutants. A method was developed for quantification of AFM images and data were found to correlate with shrinkage temperature of parchment fibres. The effects of collagen denaturation were also observed by micro-thermal analysis and at the macromolecular level by controlled-environment dynamic mechanical analysis. Internally generated volatile organic acids in storage enclosures are considered as the recent MEMORI project showed that their presence can lead to a lowering of pH, resulting in collagen denaturation and surface gelatinisation. The latter will have a different response to fluctuations in RH and temperature, and further damage will occur. In the current NANOFORART project, novel nanoparticle formulations have been developed and applied for adjustme...

Maximum removal of lactic acid (LA) from acid whey (AW) is essential for further processing of the AW waste stream. Hence, one and two step nanofiltration (NF) and nano diafiltration (NDF) approaches were applied to evaluate the removal efficiency of LA from AW at low and high pH, respectively. NDF at pH 3.0 achieved removal of $50-55% LA with a diafiltration factor (DF) of 4. Addition of diafiltration water with adjusted pH to prevent the pH fluctuations with dilutions had no significant impact on the extent of LA permeation. Adjusting pH of AW to pH 7.3 or 10.5 resulted in formation of precipitates which were removed by centrifugation, bringing about $22% removal of LA. The resultant supernatants were further subjected to NDF giving an overall LA removal of $51-55%. Additional removal of LA appeared hindered due to strong complexation of LA with lactose. This complex remained with the retentate due to the rise in molecular weight. Using a stepwise pH adjustment, first to obtain a supernatant at pH 10.5 followed by pH readjustment to 3.0 and then NF, it was possible to achieve an overall LA removal of $66%. Stepwise pH adjustment during NF of AW appears to be a feasible way to remove substantial amounts of LA to allow for downstream processing.

In this work the photocatalytic activity of paints incorporating commercial titanium dioxide for outdoor nitrogen oxide (NO) photoabatement is assessed. The paint acts as a 3D support of the photocatalyst and thus allows a larger amount of TiO2 nanoparticles to absorb light and to contact with pollutants, when compared with a 2D photocatalytic surface. NO conversion and selectivity towards nitrites and nitrates were determined according to the standard ISO 22197-1:2007 (E). Paint coatings were formulated and tested under laboratory and outdoor conditions. The best paint formulation incorporates CristalACTiV TM PC500 photocatalyst from Cristal and calcium carbonate extender, presenting a NO conversion of ca. 70% and a selectivity of ca. 40% under laboratory conditions. The same photocatalyst but characterized in the form of an optically thick film of compressed powder presented ca. 95% and 45% of conversion and selectivity, respectively. Under the real-outdoor conditions, the best performing paint showed a NO conversion of about 95%.

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Here we report the application of zinc oxide (ZnO) coated multi-walled carbon nanotube (MWCNT) composites in the photocatalytic decomposition of acetaldehyde (AA). Zinc oxide nanoparticles were successfully coated on the multi-walled carbon nanotube via impregnation process using zinc acetate (Zn(CH 3 COO) 2 × 2H 2 O) as precursor and sodium dodecyl sulfate (SDS) treated multiwalled carbon nanotube as raw material under different solvent conditions. The applied solvents during preparation were ethanol (EtOH) and water (H 2 O). As-prepared materials were characterized by thermal analysis (TG), X-ray diffraction (XRD), specific surface area measurement (BET) and transmission electron microscopy (TEM) techniques. Photocatalytic efficiencies of as-prepared composites were investigated in a stationary reactor equipped with UV lamp. Decomposition of acetaldehyde was followed by using gas chromatography (GC). Observations revealed that using impregnation method and different solvents the preparation of ZnO/MWCNT nanocomposites can be controlled easily. The highest degradation rate was achieved with the nanocomposite was synthetized using ethanol as solvent. The photocatalytic experiments revealed that the composite has higher photocatalytic activity than that of both the zinc oxide nanoparticles and the mechanical mixture of multi-walled carbon nanotube and zinc oxide.

WO3 have been synthesized using two capping agents out of which citric acid assisted WO3 was found to exhibit better response towards NOx than WO3 obtained from oxalic acid. The sensitivity was further enhanced by preparing composite with graphene.

The project Saving Oseberg is funded by the Norwegian State with the aim to preserve the Viking Age wooden objects from the Oseberg burial mound. They were excavated in 1904 near Tønsberg, Norway, and many have been treated in the past with alum salts (KAl(SO 4) 2 Á12H 2 O). Alum was widely used during the early 1900s as a treatment for archaeological wood to prevent shrinkage and impart strength. In the 1990s, conservators observed an alarming condition of the objects. Initial investigations showed that the alum treatment has initiated a slow but ongoing deterioration process, attacking the wood for over 100 years. Today, the artefacts are highly acidic and have significantly reduced mechanical strength. In the last decade, the use of nonaqueous alkaline nanoparticle dispersions has provided successful results for the protection of cellulose-based materials. Alum-treated archaeological wood samples from Oseberg, with a pH B 2, have been treated with alkaline nanoparticle dispersions, and the effects of the treatment have been evaluated by thermal analysis (TG-DTG), infrared spectroscopy (ATR-FTIR) and X-ray microtomography (micro-CT) analyses. In this contribution, the preliminary results will be presented.

Response surface methodology was adopted to obtain ternary mixed catalysts of TiO 2-loaded ZSM-5 zeolite and graphene. Oxytetracycline was used as challenged toxicant to evaluate the photocatalytic degradation efficiency of the composites. The optimal weight ratio of graphene, TiO 2 , and ZSM-5 was 1:8:1. The composites were characterized by ultraviolet-visible spectroscopy, X-ray diffraction, fourier transform infrared, N 2 adsorption-desorption isotherms, and transmission electron microscope with an energy-dispersive spectroscopy system, etc. Synthesized samples showed high stability and strong visible-light absorption efficiency. The optimal operating conditions of oxytetracycline photocatalytic degradation were achieved over a wide range of pH and temperature. With 0.1 g/L of optimal ternary mixed composite, the photocatalytic degradation of oxytetracycline was nearly reached completion within 150 min at all treatment temperatures at pH 7. Toxicity of degraded oxytetracycline solution was assayed by a boar sperm quality model using fluorescent staining and flow cytometry. During 180 min of photocatalytic treatment, the degraded oxytetracycline solution showed increasing biotoxicity and changed the morphology and function of boar sperm, despite not killing them.

Leather artifacts in historical collections and archives are often contaminated by physical changes such as soiling, which alter their appearance and readability, and by chemical changes which occur on ageing and give rise to excessive proportion of acids that promote hydrolysis of collagen, eventually leading to gelatinization and loss of mechanical properties. However, both cleaning and pH adjustment of vegetable tanned leather pose a great challenge for conservators, owing to the sensitivity of these materials to the action of solvents, especially water-based formulations and alkaline chemicals. In this study the cleaning of historical leather samples was optimized by confining an oil-in-water (o/w) nanostructured fluid in a highly retentive chemical hydrogel, which allows the controlled release of the cleaning fluid on sensitive surfaces. The chemical gel exhibits optimal viscoelasticity, which facilitates its removal after the application without leaving residues on the object. Nanoparticles of calcium hydroxide and lactate, dispersed in 2-propanol, were used to adjust the pH up to the natural value of leather, preventing too high alkalinity which causes swelling of fibers and denaturation of the collagen. The treated samples were characterized using Scanning Electron Microscopy (FE SEM), controlled environment dynamic mechanical analysis (DMA-RH), and infrared spectroscopy (ATR-FTIR). The analytical assessment validated the use of tools derived from colloid and materials science for the preservation of collagen-based artifacts.

In this work, detail investigation on UV photocatalytic dye decomposition activity is done with Zinc Orthotitanate (Zn 2 TiO 4) nanoparticles grown by solid state reaction method and shown that these nanoparticles can show 6 times higher activity than standard commercial TiO 2 nanoparticles Degussa P25. This activity is the highest among all the nanoparticles that have been compared with P25 so far. The potential cause for higher activity is explored through absorption spectroscopy. The Zn 2 TiO 4 nanoparticles are prepared from laboratory grade ZnO and TiO 2 powder of extremely low cost. Excellent recycling ability of Zn 2 TiO 4 nanoparticles is shown through their multiple usages.

In this research work, tungsten trioxide (WO 3) and activated doped WO 3 composites were prepared for the photocatalytic degradation of rhodamine-B. Activated carbon was prepared by waste sugarcane burgesses, tungsten trioxide (WO 3) was synthesized by precursor sodium tungstate dihydrate (Na 2 WO 4 •2H 2 O) using hydrothermal method. To study the morphology, functional groups, band gap, purity and optical properties of the prepared catalyst SEM, FTIR, PL and UV-Vis spectroscopy were used. SEM micrograph shows that tungsten trioxide has nanocubic rods-like structure with size 50-500 nm. Morphological results showed that nano rods become sharper when activated carbon were added in WO 3. The average nanorods have average size 20-250 nm which is very efficient for degradation. UV-Vis spectroscopy shows that band gap of the fabricated catalyst changes from 2.76 to 2.26 eV by varying the concentration ratio of the activated carbon. FTIR analysis the functional groups of the prepared catalyst. PL-spectroscopy determined that the maximum excitation wavelength was 446 nm. Photocatalytic results show that 2% activated carbon doped WO 3 composite shows the maximum degradation rate as compare to the other prepared catalyst. Synthesized catalysts are environment friendly, cost effective and due to low band gap very useful for the degradation purpose.

The complete removal of biorecalcitrant xenobiotics, including most notably the pharmaceutical pollutants, by advanced oxidation processes is often difficult to be reached in urban or industrial wastewater because of the high concentration of organic and inorganic scavengers that compete with the xenobiotics for the oxidizing species. This work investigates a coupled treatment train in which wastewater effluents are pretreated with a negatively charged loose nanofiltration (NF) membrane (HydraCoRe70, made up of sulfonated polyethersulfone) to enhance the removal of xenobiotics with the thermal Fenton process. Carbamazepine (CBZ), a drug prescribed mainly for epilepsy treatment, is used here as a model xenobiotic. After optimizing the conditions for separation and degradation, the NF−Fenton approach was applied to both synthetic wastewater and real samples to assess the overall efficiency of CBZ removal. The Fenton degradation of CBZ was drastically enhanced in nanofiltered samples, thanks to the removal by the membrane of nearly all organic matter that would otherwise consume the reactive oxidizing species (e.g., the hydroxyl radical). On the basis of a preliminary treatment cost analysis, it can be concluded that the combined process is potentially applicable to the treatment of several kinds of wastewaters (e.g., industrial ones) to favor the removal of biorecalcitrant contaminants. Key cost savings of NF−Fenton concern the lower amounts of Fenton reagents needed to degrade CBZ and (even more importantly) the decreased levels of acids and bases for pH adjustment before and after the oxidative process because of the lower buffer capacity of the NF permeate compared to feed wastewater, after the removal by the NF of many inorganic ions and most organic carbon.

Hydrated tungsten oxide nanoparticles have been synthesized using a simple wet chemical method while varying the concentration of HCl. XRD studies show that the variation in HCl concentration from 1 M to 6 M in the reaction results into gradual change in crystal structure of hydrated WO 3 from hexagonal (WO 3 Á 0.33H 2 O) to pure orthorhombic (WO 3 Á H 2 O), through a series of samples with mixed phase of the two indifferent ratios. The similar variations in the degree of hydration and phase variations have also been observed from Raman, FTIR and TGA studies. The average crystallite size of the hydrated WO 3 particles was estimated to be $ 26 nm from XRD line broadening and AFM studies showed the formation of spherical shaped particles for all the samples. The photochromic studies were carried out on the composite films of these materials in the polymeric matrix of polyvinyl alcohol (PVA) while exposing to UV light. The composite films show interesting variations in the photochromic behavior depending on the crystal structure of hydrated WO 3 filler. The photochromic behavior has been explained on the basis of EPR spectra of hydrated WO 3 .

Nanocrystalline fluorinated titania has been prepared using microwave-assisted hydrothermal crystallization of hydrous titania in a NH 4 F aqueous solution. Thus, obtained TiO 2 has exhibited excellent photocatalytic activity in the reaction of crystal violet dye photodegradationup to twofold higher than the photocatalytic activity of the commercial Evonik Aeroxide 1 TiO 2 P25 photocatalyst. Hydrothermal treatment temperature and the concentration of ammonium fluoride in the reaction mixture have been shown to be key parameters, providing the most significant effect on the microstructure and photocatalytic activity of titania. 2015 Elsevier B.V. All rights reserved.

This paper aims to study the influence of the environmental factors upon the ageing resistance characteristics of bookbinding leather treated with an oligomeric melamineformaldehyde resin modified by benzenesulfonation (BSMF). Leather treated with 0.25 g BSMF as dry matter (DM)/g leather acquired significant hydrothermal and dimensional stability to environmental factors, compared with the untreated leather, when subjected to identical accelerated ageing parameters (T = 50oC, RH = 90% for 24h, SO2 concentration in air = 0.04 mg/L). FTIR-ATR spectra and SEM images of treated leather indicated a minimal damage of the collagen structure: crosslinking bridges between resin and collagen functional groups proved to be stable to the accelerated ageing conditions, which must be assigned to the BSMF product ability to slow down the acid hydrolysis processes. This is related both to the crosslinking ability of BSMF between the collagen macromolecule chains and to its acid buffer behaviour.

The present experimental study investigate the use of aloe vera gel as an innovative material to reinforce the degraded leather. The effectiveness of the proposed material was assessed by measuring the mechanical properties, color change, infrared spectroscopy, pH measurement, and microscopic examination. The results showed the effectiveness of the gel material in improving the tensile strength, elongation, and reducing the color change during the aging process without affecting the degree of pH as well as its ability to penetrate the fiber cells, which contributed to increase the size of fibers, fiber bundles, and the cohesion of internal structure of the leather as explained the results of SEM. Although gel has no effect in inhibiting the growth of fungi, it has helped reduce growth slightly.

In this work we present a theoretical-experimental study of optics effects in nanostructures formed during the growth of titania nanotubes. Titania nanotubes were fabricated via electrochemical anodization method using Ethylene glycol. Traces or prints left by the nanotubes on the titanium surface are observed thought X-ray diffraction measurements. The pattern shows a polycrystalline structure with the presence of Anatase and titanium phases. The reflectance and absorbance spectra reveal in the traces optical phenomena similar to iridescence. The iridescence behavior is commonly found in nature and is traditionally associated to photonic properties. Using the plane wave method and modelling the nanostructures observed on the interphase like two-dimensional photonic crystals, the photonic dispersion relation was calculated in function of geometrical parameters. Enlargement of the photonic band gap was found as spatial contrast is increased. These results suggest that these types of nanostructures can be promissory candidates to develop photonic devices.

Hydrated tungsten oxide (WO 3 ÁH 2 O)-based nanoparticles were synthesized using a simple and inexpensive facile microwave irradiation process, by doping chromium (2 wt%, 3 wt%, 5 wt% and 7 wt%) at 2.45 GHz with the power of 180 W for 10 min for gas sensor application. The resultant products were annealed at 600°C at the ambient atmosphere in order to improve the crystallinity and to remove the impurities. The products were characterized by using powder XRD which confirmed the formation of orthorhombic and monoclinic structure of both as-prepared and annealed samples, respectively. Atomic force microscope shows the role of chromium in determining the surface morphology of the resultant products at microscopic level, Fourier transform infrared spectroscopic analysis confirmed the presence of essential functional groups formed through chemical bonds of the end products, room temperature UV-VIS DRS studies showed the optical behavior of the samples through emissions and band gap energy of the respective materials. Cyclic voltammetry study confirmed the suitability of the prepared chromium-doped tungsten oxide (WO 3) materials through electrochemical property for photocatalytic and sensor applications.

Tungsten trioxide (WO3) is a transition metal oxide exhibiting unique properties suitable for various applications as in electrochromic devices, gas sensors, photocatalysis, and antimicrobial activities. Preparation of WO3 nanostructures with controlled crystal structure and morphology is, thus, receiving greater attention. In this study, a facile and eco-friendly method was employed to successfully synthesis tungsten trioxide nanoparticles with monoclinic structure from Rhamnus prinoides plant leaf extract and sodium tungstate precursor. The obtained powder was characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Antibacterial activities of the synthesized WO3 nanoparticles were evaluated against Gram-positive and Gram-negative bacteria such as Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella typhimurium.

Leather artifacts in historical collections and archives are often contaminated by physical changes such as soiling, which alter their appearance and readability, and by chemical changes which occur on ageing and give rise to excessive proportion of acids that promote hydrolysis of collagen, eventually leading to gelatinization and loss of mechanical properties. However, both cleaning and pH adjustment of vegetable tanned leather pose a great challenge for conservators, owing to the sensitivity of these materials to the action of solvents, especially water-based formulations and alkaline chemicals. In this study the cleaning of historical leather samples was optimized by confining an oil-in-water (o/w) nanostructured fluid in a highly retentive chemical hydrogel, which allows the controlled release of the cleaning fluid on sensitive surfaces. The chemical gel exhibits optimal viscoelasticity, which facilitates its removal after the application without leaving residues on the object. Nanoparticles of calcium hydroxide and lactate, dispersed in 2-propanol, were used to adjust the pH up to the natural value of leather, preventing too high alkalinity which causes swelling of fibers and denaturation of the collagen. The treated samples were characterized using Scanning Electron Microscopy (FE SEM), controlled environment dynamic mechanical analysis (DMA-RH), and infrared spectroscopy (ATR-FTIR). The analytical assessment validated the use of tools derived from colloid and materials science for the preservation of collagen-based artifacts.

Hydrated tungsten oxide (WO 3 ÁH 2 O)-based nanoparticles were synthesized using a simple and inexpensive facile microwave irradiation process, by doping chromium (2 wt%, 3 wt%, 5 wt% and 7 wt%) at 2.45 GHz with the power of 180 W for 10 min for gas sensor application. The resultant products were annealed at 600°C at the ambient atmosphere in order to improve the crystallinity and to remove the impurities. The products were characterized by using powder XRD which confirmed the formation of orthorhombic and monoclinic structure of both as-prepared and annealed samples, respectively. Atomic force microscope shows the role of chromium in determining the surface morphology of the resultant products at microscopic level, Fourier transform infrared spectroscopic analysis confirmed the presence of essential functional groups formed through chemical bonds of the end products, room temperature UV-VIS DRS studies showed the optical behavior of the samples through emissions and band gap energy of the respective materials. Cyclic voltammetry study confirmed the suitability of the prepared chromium-doped tungsten oxide (WO 3) materials through electrochemical property for photocatalytic and sensor applications.

The aim of the research is to present a system recently developed and used for automated cleaning of artworks and to examine the suitability of using this ultrafast and precise computed-scanning picosecond laser (1064 nm) with a repetition rate of 10 kHz and a temporal pulse length of 10 ps for the removal of soiling from leather buckles without damaging the leather substrate. Preliminary tests will be performed with the model artificially aged vegetable tanned samples to determine the leather damage threshold fluence and the soiling ablation threshold fluence before using a laser for the removal of the soiling from a historical leather buckle. As laser cleaning requires a physical parameterization for optimization of cleaning accompanied with an assessment of the morphological and chemical changes of leather, an investigations were performed to determine the leather damage and ablation threshold fluences of artificially aged and historical vegetable tanned leather using a number of analytical techniques including differential scanning calorimetry, optical microscopy, scanning electronic microscope with energy dispersive X-ray analysis, colorimetry and Fourier transform infrared spectroscopy have been used. Following optimization trials of the picosecond laser cleaning parameters on model leather samples, satisfactory removal of the soiling over the historical leather surface is achieved.

In this research work, tungsten trioxide (WO 3 ) and activated doped WO 3 composites were prepared for the photocatalytic degradation of rhodamine-B. Activated carbon was prepared by waste sugarcane burgesses, tungsten trioxide (WO 3 ) was synthesized by precursor sodium tungstate dihydrate (Na 2 WO 4 •2H 2 O) using hydrothermal method. To study the morphology, functional groups, band gap, purity and optical properties of the prepared catalyst SEM, FTIR, PL and UV-Vis spectroscopy were used. SEM micrograph shows that tungsten trioxide has nanocubic rods-like structure with size 50-500 nm. Morphological results showed that nano rods become sharper when activated carbon were added in WO 3 . The average nanorods have average size 20-250 nm which is very efficient for degradation. UV-Vis spectroscopy shows that band gap of the fabricated catalyst changes from 2.76 to 2.26 eV by varying the concentration ratio of the activated carbon. FTIR analysis the functional groups of the prepared catalyst. PL-spectroscopy determined that the maximum excitation wavelength was 446 nm. Photocatalytic results show that 2% activated carbon doped WO 3 composite shows the maximum degradation rate as compare to the other prepared catalyst. Synthesized catalysts are environment friendly, cost effective and due to low band gap very useful for the degradation purpose.

Fourier transform infra red spectroscopy and SEM-EDX were employed to analyse the alterations on the surface of tanned goat skin induced by a number of cleaning media, by investigating the molecular structure and elemental abundance correspondingly, on a set of tanned leather samples. The obtained experimental data indicate the removal of certain molecular components from the leather surface in specific cases and suggest a methodology to correlate the action of cleaning agents to the molecular conformation of leather collagen.

This paper aims to study the influence of the environmental factors upon the ageing resistance characteristics of bookbinding leather treated with an oligomeric melamineformaldehyde resin modified by benzenesulfonation (BSMF). Leather treated with 0.25 g BSMF as dry matter (DM)/g leather acquired significant hydrothermal and dimensional stability to environmental factors, compared with the untreated leather, when subjected to identical accelerated ageing parameters (T = 50oC, RH = 90% for 24h, SO2 concentration in air = 0.04 mg/L). FTIR-ATR spectra and SEM images of treated leather indicated a minimal damage of the collagen structure: crosslinking bridges between resin and collagen functional groups proved to be stable to the accelerated ageing conditions, which must be assigned to the BSMF product ability to slow down the acid hydrolysis processes. This is related both to the crosslinking ability of BSMF between the collagen macromolecule chains and to its acid buffer behaviour.

Tungsten trioxide (WO3) has applications in various electrochromic devices and is fabricated using various techniques, which affect its electrochromic properties. In this study, tungsten trioxide (WO3) nanoplates were synthesised via a two-step facile synthesis process using a hydrothermal technique on seeded fluorine-doped tin oxide (FTO) glass substrates. WO3 nanoplates with high porosity were obtained using a fast and simple hydrothermal method. First, a seed layer was grown on FTO using a spin coating process. WO3 nanoplates were then quickly synthesised on the seeded FTO glass using a hydrothermal technique at 200 ̊C for 1h. The nanoplates were characterizated by using XRD, SEM, Chronoamperometry and Cyclic Voltammetry techniques. The WO3 nanoplates have got a crystal structure mixed monoclinic and hexagonal phases. The crystal grain sizes of the film was found to be 36 and 53 nm for the (011) and (200) sharpest crystal planes of monoclinic and hexagonal crystal phases respecti...

Aqueous suspensions of highly stable Mg/Al layered double hydroxide (LDH) nanoparticles were obtained via a direct and fully colloidal route using asymmetric poly(acrylic acid)-b-poly(acrylamide) (PAA-b-PAM) double hydrophilic block copolymers (DHBCs) as growth and stabilizing agents. We showed that hybrid polyion complex (HPIC) micelles constituted of almost only Al(3+) were first formed when mixing solutions of Mg(2+) and Al(3+) cations and PAA3000-b-PAM10000 due to the preferential complexation of the trivalent cations. Then mineralization performed by progressive hydroxylation with NaOH transformed the simple DHBC/Al(3+) HPIC micelles into DHBC/aluminum hydroxide colloids, in which Mg(2+) ions were progressively introduced upon further hydroxylation leading to the Mg-Al LDH phase. The whole process of LDH formation occurred then within the confined environment of the aqueous complex colloids. The hydrodynamic diameter of the DHBC/LDH colloids could be controlled: it decreased fr...

In this research work, tungsten trioxide (WO 3) and activated doped WO 3 composites were prepared for the photocatalytic degradation of rhodamine-B. Activated carbon was prepared by waste sugarcane burgesses, tungsten trioxide (WO 3) was synthesized by precursor sodium tungstate dihydrate (Na 2 WO 4 •2H 2 O) using hydrothermal method. To study the morphology, functional groups, band gap, purity and optical properties of the prepared catalyst SEM, FTIR, PL and UV-Vis spectroscopy were used. SEM micrograph shows that tungsten trioxide has nanocubic rods-like structure with size 50-500 nm. Morphological results showed that nano rods become sharper when activated carbon were added in WO 3. The average nanorods have average size 20-250 nm which is very efficient for degradation. UV-Vis spectroscopy shows that band gap of the fabricated catalyst changes from 2.76 to 2.26 eV by varying the concentration ratio of the activated carbon. FTIR analysis the functional groups of the prepared catalyst. PL-spectroscopy determined that the maximum excitation wavelength was 446 nm. Photocatalytic results show that 2% activated carbon doped WO 3 composite shows the maximum degradation rate as compare to the other prepared catalyst. Synthesized catalysts are environment friendly, cost effective and due to low band gap very useful for the degradation purpose.

Phenol Photodegradation in Presence of Nano or Micro-TiO2: Performance Comparison and Study of the Different By-products. C. Bianchi, M. Stucchi, C. Pirola, G. Cerrato, S. Morandi, B. Sacchi, S. Vitali,V. Capucci. (a) Università degli studi di Milano, Dip. Chimica 20133 Milano, Italy, [email protected]. (b) Università degli studi di Torino, Dip. Chimica & NIS Interdept centre 10125 Torino, Italy. (c) GranitiFiandre SpA, 42014 Castellarano, Italy. (1) Consorzio INSTM, Firenze, Italy.

WO3 have been synthesized using two capping agents out of which citric acid assisted WO3 was found to exhibit better response towards NOx than WO3 obtained from oxalic acid. The sensitivity was further enhanced by preparing composite with graphene.

Tungsten oxide (WO 3 ) is a semiconductor that can be used in a wide variety of applications such as semiconductor gas devices, electronic devices, and photocatalysts. WO 3 can be proposed as a substitute for TiO 2 because it has a narrow bandgap property, which makes this material active in the UV-Vis spectrum. The purpose of writing this paper is to conduct a literature review on the synthesis of WO 3 nanoparticles and nanocomposites using a review method on 50 literature from 2000 to 2020 by reviewing several methods such as hydrothermal methods, sol-gel, low-temperature hydrolysis and, water-in-oil microemulsion in sucrose esters, calcination, flame-assisted spray pyrolysis, ultrasonic, and microwave irradiation. Besides, it is also reviewed based on several starting materials such as sodium tungsten dihydrate, AMT (ammonium metatungsten), ammonium tungstate hydrate, H 2 WO 4 , phosphotungsten acid, Cl 6 W, and W powder.

Photocatalytic activity of semiconductor nanostructures is gaining much importance in recent years in both energy and environmental applications. However, several parameters play a crucial role in enhancing or suppressing the photocatalytic activity through, for example, modifying the band gap energy positions, influencing the generation and transport of charge carriers and altering the recombination rate. In this regard, physical parameters such as the support material and the irradiation source can also have significant effect on the activity of the photocatalysts. In this work, we have investigated the role of reduced graphene oxide (RGO) support and the irradiation source on mixed metal chalcogenide semiconductor (CdS–ZnO) nanostructures. The photocatalyst material was synthesized using a facile hydrothermal method and thoroughly characterized using different spectroscopic and microscopic techniques. The photocatalytic activity was evaluated by studying the degradation of a mode...

In this study, tungsten trioxide/titanium dioxide (WO3–TiO2) nanohybrid structures were prepared using a facile hydrothermal method. The nanosheets-like morphology was achieved for the prepared WO3–TiO2 nanohybrid that were confirmed by scanning electron microscopy. Provided X-ray photoelectron spectroscopy results also confirm the element existence and surface composition of the nanohybrid structure. The optical properties of the WO3–TiO2 nanohybrid were verified using UV–Visible diffuse reflectance spectroscopy (UV–Vis DRS) and photoluminescence spectroscopy. The UV–Vis DRS results indicated that the absorption edge for the WO3–TiO2 nanohybrid found a red shift towards the visible region due to the reduced bandgap (2.83 eV). The photocatalytic activity of the as-prepared WO3–TiO2 nanohybrid was evaluated by the photocatalytic degradation of Orange G dye in wastewaters under visible light. 94% Orange G dye was degraded in 210 min at neutral pH in the presence of WO3–TiO2 nanohybrid...

Titanium dioxide nanostructures are promising material for optical and antibacterial applications. In this study, TiO 2 nanoparticles have been synthesized using facile microwave-assisted hydrothermal process. The optical properties and the structure of the synthesized TiO 2 nanoparticles were characterized using several techniques such as Transmission Electron Microscopy (TEM), UV measurements, Fourier Transform Infrared (FTIR), Energy and Dispersive X-ray Spectroscopy (EDXS), X-ray diffraction, Scanning Electron Microscopy (SEM), and Thermogravimetric (TGA). The antibacterial activity of TiO 2 nanoparticles were assessed against the pathogenic strain E. coli ATCC ® 8739 ™. The reported results indicated superior antibacterial activity of TiO 2 nanoparticles tested against the pathogenic bacteria, which reveals potential applications of TiO 2 nanoparticles in biomedical and medical fields.

Despite the recent advancement in graphene oxide (GO) as a host material in energy and environmental sectors, its composite thin films with metal oxides such as nickel oxide (NiO) and its optical, structural, chemical state, and photocatalytic activities have been poorly explored. Herein, we have reported the GO/NiO thin films preparation by a combination of chemical and physical deposition techniques (i.e. spin coating followed by DC/RF sputtering). The asprepared composites thin films were characterised using Raman spectroscopy, X-ray diffraction/photoelectron spectroscopy scanning electron microscopy, and atomic force microscopy. The surface topography confirmed the uniform deposition of NiO over thin films of GO. The XPS results showed the formation of NiC along with the partial reduction in GO into graphene with their existing four constituents, i.e. NiO, NiC, GO, in the thin film composites. The classical plasmon, Wemple and Didomenico model, was first time applied for GO/NiO to compute energy loss functions, and dispersion energy parameters. The theoretical calculated values for the deposited GO/NiO thin films were found to be

A new titanium/molybdenum/mixed-oxides (TMO) contact-type heterojunction photocatalyst was prepared by a simple, low-cost, and environmentally-friendly mixing-calcination solid-state method. A microstructural investigation by scanning electron microscopy (SEM) showsirregularly shaped agglomerated morphology of TMO that consists of firmly connected globular TiO2 and rod-like MoO3 particles. The detailed structure and optical bandgap investigation by X-ray diffraction, Raman, and UV-Vis spectroscopy revealed the TMO’s composition of ~37 wt.% rutile TiO2, ~25 wt.% of anatase TiO2, and ~38 wt.% of molybdite MoO3 phase and an absorption threshold of around 380 nm, which implies more probability of desirable higher visible light absorption. The removal efficiency of pesticides quinmerac (QUI) and tembotrione (TEM), and pharmaceuticals metoprolol (MET), amitriptyline (AMI), ciprofloxacin (CIP),and ceftriaxone (CEF) from water in the presence of starting pure TiO2, MoO3, and prepared TMO we...

ZnO in different nanostructures were synthesized by microwave assisted hydrothermal route. Different experimental conditions such as microwave irradiation power, exposure time have been investigated to reveal the process of formation of the ZnO nanostructures. It was revealed that the microwave exposure time plays a vital role in determining the diameter of the rods. The interaction of microwaves with the growth units of ZnO was systematically investigated to explain formation of different structural geometry of ZnO on nanoscale. ZnO nanostructures consisted of flower-like, sword-like, needle-like and rods-like structures were prepared by microwave assisted hydrothermal process at different conditions of microwave power and irradiation time. The ZnO nanostructures are in hexagonal phase. It is considered that microwave can interact with growth units of ZnO to generate active centers on the surface of ZnO nuclei so that needle-like ZnO rods are created on those sites, resulting in the formation of the flower-like ZnO nanostructures. Polyaniline-ZnO nanocomposites (PZ) in various weight % of nanostructure ZnO were synthesized by the chemical oxidation method in sulphuric acid medium using ammonium persulphate as oxidant at 276K. The synthesized polymer nanocomposites were characterized by XRD, FTIR and UV-VIS spectroscopy.

Spherical microparticles of TiO2 were synthesized by the ionic liquid-assisted solvothermal method at different reaction time (3, 6, 12 and 24h). The properties of the prepared photocatalysts were investigated by means of UV-vis diffuse-reflectance spectroscopy (DRS), BET surface area measurements, scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The results indicated that the efficiency of phenol degradation was related with a time of the solvothermal synthesis as determined for TiO2_EAN(1:1)_24h sample. Microparticles of TiO2_EAN(1:1)_3h formed during the only 3h of synthesis time revealed really high photoactivity under visible irradiation – 75%. This value increased to 80% and 82% after 12h and 24h, respectively. The photoactivity increase was accompanied by the increase of the specific surface area thus pores size, as well as ability to absorb UV-vis irradiation. The high efficiency of phenol degradation of ...

Leather artifacts in historical collections and archives are often contaminated by physical changes such as soiling, which alter their appearance and readability, and by chemical changes which occur on ageing and give rise to excessive proportion of acids that promote hydrolysis of collagen, eventually leading to gelatinization and loss of mechanical properties. However, both cleaning and pH adjustment of vegetable tanned leather pose a great challenge for conservators, owing to the sensitivity of these materials to the action of solvents, especially water-based formulations and alkaline chemicals. In this study the cleaning of historical leather samples was optimized by confining an oil-in-water (o/w) nanostructured fluid in a highly retentive chemical hydrogel, which allows the controlled release of the cleaning fluid on sensitive surfaces. The chemical gel exhibits optimal viscoelasticity, which facilitates its removal after the application without leaving residues on the object. Nanoparticles of calcium hydroxide and lactate, dispersed in 2-propanol, were used to adjust the pH up to the natural value of leather, preventing too high alkalinity which causes swelling of fibers and denaturation of the collagen. The treated samples were characterized using Scanning Electron Microscopy (FE SEM), controlled environment dynamic mechanical analysis (DMA-RH), and infrared spectroscopy (ATR-FTIR). The analytical assessment validated the use of tools derived from colloid and materials science for the preservation of collagen-based artifacts.

WO 3 has emerged as an outstanding nanomaterial composite for gas sensing applications. In this paper, we report the synthesis of WO 3 using two different capping agents, namely, oxalic acid and citric acid, along with cetyltrimethyl ammonium bromide (CTAB). The effect of capping agent on the morphology of WO 3 material was investigated and presented. The WO 3 materials were characterized using X-ray diffraction analysis (XRD), field emission transmission electron microscopy (FETEM), field emission scanning electron microscopy (FESEM), particle size distribution (PSD) analysis, and UV-visible spectroscopic analysis. WO 3 synthesized using oxalic acid exhibited orthorhombic phase with crystallite size of 10 nm, while WO 3 obtained using citric acid shows monoclinic phase with crystallite size of 20 nm. WO 3 obtained using both capping agents were used to study their gas sensing characteristics, particularly for NO x gas. The cross sensitivity towards interfering gases and organic vapors such as acetone, ethanol, methanol and triethylamine (TEA) was monitored and explained. Furthermore, the composites of WO 3 were prepared with graphene by physical mixing to improve the sensitivity, response and recovery time. The composites were tested for gas sensing at room temperature as well as at 50 C and 100 C. The results indicated that the citric acid-assisted WO 3 material exhibits better response towards NO x sensing when compared with oxalic acid-assisted WO 3. Moreover, the sensitivity of the WO 3 /graphene nanocomposite was better than that of the pristine WO 3 material towards NO x gas. The WO 3 composite prepared using citric acid as capping agent and graphene exhibits sensing response and recovery time of 29 and 24 s, respectively.

ZnO nanoparticles were prepared by mechanical grinding of laboratory grade ZnO powder. These nanoparticles were characterised by using X-ray diffraction analysis, transmission electron microscopy (TEM), photoluminescence and diffuse reflectance spectroscopy. From TEM study it reveals that the particles mostly show one dimensional morphology. The average length and diameter of these nanoparticles are 300 nm and 59.34 nm respectively. Studies on UV photocatalysis behaviour of these nanoparticles were done through their use in methylene blue dye decomposition. Particularly, the reaction kinetics and reaction rate are estimated by monitoring the dye decomposition activity with respect to UV exposure time. The kinetic is found to be pseudo-first order with the reaction rate constant (kinetic constant) 0.18 min −1. In the comparative study it has been demonstrated that these ZnO nanoparticles can show three times higher dye degradation activity with respect to benchmark commercial nanoparticle P25. From the photocatalysis studies with scavengers like Isopropyl alcohol and ethylenediaminetetraacetate it is demonstrated that hole (h +) and hydroxyl radical (• OH) have a vital role in the dye decomposition activity. The used ZnO powders are of extremely low cost, so this material can be found to be a better choice for photocatalytic dye decomposition applications.

Leather artifacts in historical collections and archives are often contaminated by physical changes such as soiling, which alter their appearance and readability, and by chemical changes which occur on ageing and give rise to excessive proportion of acids that promote hydrolysis of collagen, eventually leading to gelatinization and loss of mechanical properties. However, both cleaning and pH adjustment of vegetable tanned leather pose a great challenge for conservators, owing to the sensitivity of these materials to the action of solvents, especially water-based formulations and alkaline chemicals. In this study the cleaning of historical leather samples was optimized by confining an oil-in-water (o/w) nanostructured fluid in a highly retentive chemical hydrogel, which allows the controlled release of the cleaning fluid on sensitive surfaces. The chemical gel exhibits optimal viscoelasticity, which facilitates its removal after the application without leaving residues on the object. Nanoparticles of calcium hydroxide and lactate, dispersed in 2-propanol, were used to adjust the pH up to the natural value of leather, preventing too high alkalinity which causes swelling of fibers and denaturation of the collagen. The treated samples were characterized using Scanning Electron Microscopy (FE SEM), controlled environment dynamic mechanical analysis (DMA-RH), and infrared spectroscopy (ATR-FTIR). The analytical assessment validated the use of tools derived from colloid and materials science for the preservation of collagen-based artifacts.