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Methylene blue is generally used as dyeing agent in textile, printing and pharmaceutical industries, which leads to the obtaining of large amounts of wastewater. The purpose of this study is to remove methylene blue dye from aqueous solutions using fir wood sawdust waste as low cost biosorbent material. In order to evaluate the adsorption process, analyses for determination of micrometric properties, infrared spectroscopy, optical microscopy and colorimetry were performed. To increase the efficiency of the process and the adsorption surface, the fir wood sawdust was grinded and sieved. Some specific parameters were varied in the experimental part in order to study the influence of the adsorbent support dose, concentration, temperature, contact time, volume and stirring rate. The removal efficiency of methylene blue dye was further studied for evaluating the adsorption capacity of the fir wood sawdust.

Over centuries, the external factors such as fire, low temperature, light or microbiological agents, act on the wood and induce some degradation processes, sometimes irreversible, identified by discoloration, fragility and unsightly appearance. Although there are numerous literature reports about different nanomaterials used for preservation and restoration of wood surfaces (calcium hydroxides, magnesium hydroxides, hydroxyapatite, or even organic resins as Paraloid B72), in this paper it is proposed a new system—gold hydroxyapatite (AuHAp), tested on the hazelnut wood samples (young and aged specimens), as a new solution for preservation of some wooden artifacts. This paper addresses a broad range of analytical methods: X-ray diffraction, UV–Vis spectrophotometry, Fourier transformed infrared spectroscopy, Raman spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, chromatic parameters and hardness test. Also, humidity sorption/desorption measurements are used for humidity sorption and desorption evaluation. The adsorption and desorption tests determined the hydroscopic sorption properties of the wood specimens by measuring the mass of the specimens in equilibrium with air at a specific temperature and RH. All the results concluded that after the application of the new system on the hazelnut wood surface, a well distributed and uniform layer consisting from AuHAp systems with a network aspect are observed, which covers the wood vessels and fibers, filling the voids and stopping the wood weathering process, more accentuated at aged wood than at the young species.

The paper describes an innovative bio-design of some hybrid nanoarchitectures containing bioartificial membranes and silver nanoparticles phytogenerated by using a natural extract Caryophyllus aromaticus (cloves) that contains many bioactive compounds. Two kinds of liposomes with and without chlorophyll a (Chla) obtained through thin film hydration method were used to achieve bio-green-generated hybrids by a simple, cost effective bottom-up approach. The characteristic peaks of CE-nAg monitored by UV–Vis absorption have firstly demonstrated the biohybrids formation. The slightly blue shift and fluorescence quenching observed by fluorescence emission spectra highlighted the formation of hybrid systems by biointeraction between lipid vesicles and silver nanoparticles. The incorporation of silver nanoparticles in lipid vesicles resulted in significant changes of FT-IR spectra of liposomes, indicating a reorganization of biomimetic membranes. All the microscopic methods (SEM, AFM and TEM) confirmed the biosynthesis of “green” AgNPs together with associated biohybrids, their spherical and quasi-spherical shapes with nano-scaled size. By TEM assay it was shown that CE-nAg are surrounded by petal like cloud structures that consist of biopolymers like proteins or polysaccharides and other phytochemicals arising from clove extract. EDS spectra confirmed the formation of phyto-nanoAg and also the presence of silver in the biohybrids. In addition, Selected Area Electron Diffraction showed characteristic polycrystalline ring patterns for a cubic structure of the clove-generated AgNPs. The hybrid materials showed efficient physical stability, i.e. ξ value of −28.0 mV (for biohybrids without Chla, BH) and of −31.7 mV (for biohybrids labelled with Chla, Chla-BH), assured by strong electrostatic repulsive forces between particles. The “green” nano-silver particles (CE-nAg) showed remarkable antioxidant activity (AA = 90.2%). The biohybrids loaded with clove-AgNPs proved to be more effective, scavenging about 98.8% of free radicals (in case of Chla-BH), and of 92.6% (in case of BH). The antibacterial effectiveness showed that green AgNPs combine in a synergistic manner the antibacterial properties of clove extract with those of silver, resulting in an enhancement of inhibition diameter, by 20%. Chla-BH proved to be more potent against Escherichia coli, than BH, exhibiting an inhibition diameter of 42 mm. Regarding the in vitro cytotoxicity against tumour cells, the CE-nAg concentration significantly influenced the cell viability, i.e. IC50 was 3.6% (v/v) for HT-29 cells. Chla-BH was more effective against HT-29 cancer cells at the concentrations ranging from 0 to 18% (v/v), when the normal cells were not affected. Clove-generated AgNPs exhibited haemolytic activity against hRBCs, while the biohybrids were haemocompatible. The action mechanism on the two cell lines (mouse fibroblast L929 cells and human colorectal adenocarcinoma HT-29 cells) investigated by fluorescence microscopy demonstrated that CE-nAg killed almost all the cells (94%) through necrosis at a concentration of 33.4% (v/v). The treatment of HT-29 cells with BH resulted in: 71.5% viable cells, 19.5% apoptotic and only 9% necrotic cells, while in the case of Chla-BH treatment, only 77.5% cells were viable, 16% cells were apoptotic and 6.5% were necrotic. In this way, the developed silver-based nanoparticles can represent viable promoters to develop new biohybrids with improved features, e.g. antioxidant and antibacterial effectiveness, haemolytic activity and greater specificity towards tumour cells.

Knowledge of the chemical composition of the building materials of the monuments may help us to preserve and protect them from the pollution of our cities. The aim of this work is to characterize the materials of the walls from ancient buildings, the decay products that could be appear due to the action of pollution and a new method based on nanomaterials (hydroxyapatite -HAp) for a conservative preservation of the treated walls. Some analytical techniques have been used, as follow: X-ray fluorescence energy dispersive (EDXRF) (for the relative abundance of major, minor and trace elements), FTIR and Raman spectroscopy (for stratigraphic study of cross-sections of multi-layered materials found in wall paintings), Optical microscopy (OM), (for morphology of the wall samples). The nanomaterial suspension HAp applied on the sample surface by spraying, decreased the capillary water uptake, do not modify significantly the color of the samples and induced a reduced mass loss for the treated samples.

Snake fruit (Salacca zalacca) is a palm tree species, which is found in Malaysia and Indonesia. This study was conducted to investigate and compare the composition, total phenolic, flavonoid, tanins and monoterpenoids contents in the core and shell fruits. Concentration values of extracts were obtained from standard curves obtained. Antioxidant activity was determined using DPPH method. For all methods it was used the UV-VIS Specord M40, using different wavelength. The infrared spectral analysis was carried out to caracterized the type of functional group existent in snake fruit parts (shell and core).