Preparation and properties of novel binary and ternary highly amorphous poly(vinyl alcohol)-based composites with hybrid nanofillers.

Smart protective coatings and devices are currently of great interest. In particular, they can absorb or reflect harmful waves of electromagnetic interference (EMI). In this work, novel binary and ternary composites with highly amorphous poly(vinyl alcohol) (HAVOH) as a matrix and single-walled carbon nanotubes (SWCNTs) and MXenes as nanofillers were prepared. HAVOH is a recently patented kind of poly(vinyl alcohol) (PVOH) that was modified with diol monomers. MXenes are a new type of inorganic two-dimensional (2D) nanoparticle consisting of carbides, nitrides and carbonitrides. Three series of composites, HAVOH/SWCNTs, HAVOH/MXenes and HAVOH/SWCNTs/MXenes, were prepared using the solvent casting method. Samples were tested with various methods to study their structure, electrical properties, thermal behavior and EMI-shielding properties. HAVOH/3.0 wt.% SWCNTs/3.0 wt.% MXene specimens revealed a shielding effectiveness of 55 dB, which is 122 times better than that of the neat matrix. These results are promising for the fabrication of films with protective effects against EMI.

Comparison of biodegradable polyesters degradation behavior in sand.

Sandy beaches represent environmental compartments particularly vulnerable to litter pollution, and they reflect the magnitude of pollution of adjacent compartments: water and coastal areas. The substitution of conventional polymers by biodegradable materials is generally considered as an alternative for reducing environmental accumulation of plastic debris. The present study is aimed to investigate the degradation of poly(lactic acid), poly(ε-caprolactone), poly(butylenesuccinate adipate) and poly(3-hydroxybutyrate) buried in sand for 267 days, simulating them as beach litter. The analysed polyesters showed different degradation mechanisms and kinetics. PLA is mainly subjected to weathering by physical aging; after an initial faster degradation of the amorphous phase, PCL showed a decrease of its degradation rate; similarly to PCL, the degradation of PBSA started from the amorphous phase; PHB is clearly subjected to biological degradation. The degradation trend of the investigated materials in sand decreased in the order PHB > PBSA > PCL > PLA. PLA, PCL and PBSA did not undergo complete degradation in sand during the testing time.

Polyvinylpyrrolidone/Montmorillonite/Zinc Oxide Bionanosystems Prepared by Spray Drying.

In this study, microparticles of bionanomaterials were obtained by polyvinylpyrrolidone, montmoril-lonite, and zinc oxide bionanosystems produced through solution intercalation technique combined with a spray-drying process, aiming for possible application as drug delivery systems. The final microparticles obtained were evaluated in terms of their production yield, which varies between 39.2% and 56.9%. Thermal analysis showed no major changes in Tg of the nanocomposites, compared to the pure PVP polymer. Scanning electron microscopy analysis revealed a pseudo-spherical shape and confirmed the micrometric size of the microparticles. Transmission electron microscopy analysis corroborated the embedding of montmorillonite and ZnO within the polymer phase. Nuclear magnetic resonance and X-rays diffraction were used to study the nanoparticles dispersion, indicating a predominant intercalated morphology. This study suggests that the applied methodology is suitable for the high yields synthesis of nanocomposites PVP based microparticles with uniform size and shape, which can be promising for the production of a new drug delivery system.

Marketing and legal status of phytomedicines and food supplements in Morocco.

OBJECTIVES: The Phytomedicine (PM) and Food supplements (FS) Market is considerably growing in Morocco a review of state is necessarily to structure and improve it. METHODS: Information was collected directly from the pharmacist through a questionnaire-based survey who was conducted in 284 pharmacies in the region of Fez-Meknes in Morocco. Data were analyzed and classified using relative frequency of citations (RFC). RESULTS: More than 98% of the pharmacies commercialized the PM and FS, 80% of the pharmacists deny the existence of a real area dedicated to them, the majority (94%) of them prefer phytomedicine rather than classic drugs. This study reported about 64 products as the most used by the population of the region of Fez-Meknes among them 48 FS (75%) and 16 PM (25%) and the most marketed products are used for Transit Disorders (28.34%), then Anxiety (22.17%) and ENT Disease (20.18%). CONCLUSIONS: Despite the fact that Morocco is a country where people use medicinal plants daily, the commercialization of the PM and FS is still unstructured. Due to legal problem the PM Sold in the market are mainly exported. To assure development and also valorization of this sector the regulation of this market is highly required.

Hyper-Crosslinked Polymer Nanocomposites Containing Mesoporous Silica Nanoparticles with Enhanced Adsorption Towards Polar Dyes.

The development of new styrene-based hyper-crosslinked nanocomposites (HCLN) containing mesoporous silica nanoparticles (MSN) is reported here as a new strategy to obtain functional high surface area materials with an enhanced hydrophilic character. The HCLN composition, morphology and porous structure were analyzed using a multi-technique approach. The HCLN displayed a high surface area (above 1600 m2/g) and higher microporosity than the corresponding hyper-crosslinked neat resin. The enhanced adsorption properties of the HCLN towards polar organic dyes was demonstrated through the adsorption of a reactive dye, Remazol Brilliant Blue R (RB). In particular, the HCLN containing 5phr MSN showed the highest adsorption capacity of RB.

Microfiber Release to Water, Via Laundering, and to Air, via Everyday Use: A Comparison between Polyester Clothing with Differing Textile Parameters.

Textiles are one of the major sources of microplastic pollution to aquatic environments and have also been reported in dry and wet atmospheric deposition. There is still a lack of information on the direct release of microfibers from garments to the air and on the influence of textile characteristics including structure, type of yarn, and twist. The present study examines microfiber emissions directly to the air and to water as a consequence of laundering. Polyester garments with different textile characteristics were examined including various material compositions, fabric structure, yarn twist, fiber type, and hairiness. Scaling up our data indicates release of microfibers per person per year to the air is of a similar order of magnitude to that released to wastewater by laundering. The lowest releases to both air and water were recorded for a garment with a very compact woven structure and highly twisted yarns made of continuous filaments, compared with those with a looser structure (knitted, short staple fibers, lower twist). Our results demonstrate for the first time that direct release of microfibers from garments to air as a consequence of wear is of equal importance to releases to water. Currently there is considerable interest in interventions focused on capture from wastewater. However, our results suggest more effective interventions are likely to result from changes in textile design that could reduce emissions to both air and water.

Critical Factors for the Recycling of Different End-of-Life Materials: Wood Wastes, Automotive Shredded Residues, and Dismantled Wind Turbine Blades.

Different classes of wastes, namely wooden wastes, plastic fractions from automotive shredded residues, and glass fiber reinforced composite wastes obtained from dismantled wind turbines blades were analyzed in view of their possible recycling. Wooden wastes included municipal bulky wastes, construction and demolition wastes, and furniture wastes. The applied characterization protocol, based on Fourier transform infrared (FTIR) spectroscopy in attenuated total reflection (ATR) mode, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX), and thermogravimetric analysis (TG) coupled with FTIR spectrometry for the investigation of the evolved gases, revealed that the selected classes of wastes are very complex and heterogeneous materials, containing different impurities that can represent serious obstacles toward their reuse/recycling. Critical parameters were analyzed and discussed, and recommendations were reported for a safe and sustainable recycling of these classes of materials.

The contribution of washing processes of synthetic clothes to microplastic pollution.

Microplastic pollution caused by washing processes of synthetic textiles has recently been assessed as the main source of primary microplastics in the oceans. Therefore, understanding the effective contribution of the washing process of synthetic clothes to this environmental problem, is of great importance. In this study, wash trials at real scale were performed on commercial clothes by using a household washing machine in order to gain reliable data about the release of microplastics, and to identify possible influences of textile characteristics on the release. The wastewater was collected and filtered through subsequent filters with decreasing porosity, and the amount and dimensions of microfibres were determined. Microfibre release was analysed in relation to the nature and characteristics of the washed clothes. Results showed that microfibres released during washing range from 124 to 308 mg for kg of washed fabric depending from the type of washed garment that corresponds to a number of microfibres ranging from 640,000 to 1,500,000. Some textile characteristics, such as the type of fibres constituting the yarns and their twist, influenced the release of microfibres during washing. A great amount of microfibres of cellulosic nature was also released during washing of clothes made with a blend of polyester/cellulose. Finally the most abundant fraction of microfibres shed was retained by filters with pore size of 60 µm, presenting an average length of 360-660 µm and an average diameter of 12-16 µm, indicating dimensions that could pass through wastewater treatment plants and pose a threat for marine organisms.

Recycling Polyethylene-Rich Plastic Waste from Landfill Reclamation: Toward an Enhanced Landfill-Mining Approach.

In the frame of a circular economy, the maximization of secondary raw-material recovery is necessary to increase the economic and environmental sustainability of landfill mining and reclamation activities. In this paper, the polyethylene-rich plastic fraction recovered from the reclamation of an abandoned industrial landfill (landfill-recovered plastic, LRP) has been characterized through spectroscopic, thermal, morphological, and mechanical analyses. Then, an economically viable valorization and recycling strategy was set up. The effectiveness of this strategy in the enhancement of LRP properties has been demonstrated through morphological and mechanical characterizations.

Design of functional textile coatings via non-conventional electrofluidodynamic processes.

HYPOTHESIS: In the last years, several cost-effective technologies have been investigated to functionalize textile substrates for large scale applications and industrial production. However, several limitations of currently used technologies still restrict the capability to form functional coatings finely controlling the textile surface properties and topographic structure of the coatings at sub-micrometric scale. EXPERIMENTS: Herein, we introduced a new non-conventional electrofluidodynamic technology - based on the use of electrostatic forces to polymer/composite solutions - for the application onto textile fabrics of functional coatings. With respect to particle/fibrous coatings usually applied through conventional electrospraying/electrospinning processes, the proposed approach is able to realize homogeneous and continuous coatings by a one-step process, imparting tailored functionalities to the textiles surfaces through the use of customized experimental setups. FINDINGS: We proved that this process can be successfully used to realize functional coatings based on a bioderived polymer, namely polylactic acid (PLA), on commercial woven polyamide (PA) fabrics. In addition, due to the usage of graphene derivatives or photochromic dyes in combination with PLA, the applied coatings are able to confer peculiar functionalities (i.e., electrical conductivity, photochromic properties, etc.) to polyamide fabrics, as proved by SEM, conductivity and UV irradiation measurements, for innovative applications in smart textiles, e-health and wearable electronics.

Pectin based finishing to mitigate the impact of microplastics released by polyamide fabrics.

Washing processes of synthetic clothes have been identified as the main source of microplastic pollution in marine ecosystems. Textile microfibres have been found in marine sediments and organisms, posing a real threat for the environment. The development of mitigation approaches is strongly needed to prevent the impact of microplastics. In this work, an innovative finishing treatment of polyamide fabrics is proposed to mitigate the microplastic impact, by preventing the damage of fabrics during washings. The treatment is based on the use of pectin, a natural polysaccharide present in the cell walls of plants. To functionalize the fabric, pectin was firstly modified with glycidyl methacrylate (GMA) and then grafted on polyamide. Washing tests of treated fabrics showed the effectiveness of the treatment in reducing of about 90% the amount of microfibres released by untreated fabrics. Post-wash analysis of the treated fabrics revealed a promising resistance to the washing process.

Effect of Microfibrillated Cellulose on Microstructure and Properties of Poly(vinyl alcohol) Foams.

Poly(vinyl alcohol) foams, containing different amounts of microfibrillated cellulose, were prepared through an eco-friendly procedure based on high-speed mixing and freeze-drying. The effect of filler amount on cell shape and regularity was studied by scanning electron microscopy (SEM) and the evolution of the microstructure was assessed through dynamic cryo-SEM. Fourier Transformed Infrared Analysis and Differential Scanning Calorimetry measurements revealed the presence of hydrogen bond interaction among cellulosic filler and the matrix. The modulus and compression deflection of neat PVA were significantly improved by increasing the amount of microfibrillated cellulose content with respect to foams realised with pulp cellulose fibers.

Evaluation of microplastic release caused by textile washing processes of synthetic fabrics.

A new and more alarming source of marine contamination has been recently identified in micro and nanosized plastic fragments. Microplastics are difficult to see with the naked eye and to biodegrade in marine environment, representing a problem since they can be ingested by plankton or other marine organisms, potentially entering the food web. An important source of microplastics appears to be through sewage contaminated by synthetic fibres from washing clothes. Since this phenomenon still lacks of a comprehensive analysis, the objective of this contribution was to investigate the role of washing processes of synthetic textiles on microplastic release. In particular, an analytical protocol was set up, based on the filtration of the washing water of synthetic fabrics and on the analysis of the filters by scanning electron microscopy. The quantification of the microfibre shedding from three different synthetic fabric types, woven polyester, knitted polyester, and woven polypropylene, during washing trials simulating domestic conditions, was achieved and statistically analysed. The highest release of microplastics was recorded for the wash of woven polyester and this phenomenon was correlated to the fabric characteristics. Moreover, the extent of microfibre release from woven polyester fabrics due to different detergents, washing parameters and industrial washes was evaluated. The number of microfibres released from a typical 5 kg wash load of polyester fabrics was estimated to be over 6,000,000 depending on the type of detergent used. The usage of a softener during washes reduces the number of microfibres released of more than 35%. The amount and size of the released microfibres confirm that they could not be totally retained by wastewater treatments plants, and potentially affect the aquatic environment.

Topical treatment of experimental cutaneous leishmaniasis in golden hamster (Mesocricetus auratus) with formulations containing pentamidine

O tratamento atual para Leishmaniose Tegumentar Americana é realizado com antimoniais pentavalentes como tratamento padrão, e as drogas de segunda escolha incluem pentamidina e anfotericina B, mas essas terapias apresentam efeitos colaterais e requerem administração parenteral. O objetivo deste trabalho foi avaliar formulações tópicas contendo isetionato de pentamidina comercial (IP) no tratamento da leishmaniose cutânea experimental (LC). Hamsters dourados foram infectados no focinho com Leishmania (Leishmania) amazonensis. Grupos de seis animais receberam tratamento tópico com cremes anidro ou emulsões hidratantes, num máximo de 10 dias, com aplicação de 50 mg dia-1. Amostras de tecido de lesões tratadas foram avaliadas por histologia, microscopia eletrônica de transmissão (MET) e cultivo de biópsia. Comparado ao grupo sem tratamento, o tratamento tópico com emulsão hidratante com 10% de IP e ácido úsnico (ACE5AU) mostrou diminuição significativa (P=0,028) nas medidas de lesões, 20 dias após o final do tratamento e 27,37% de redução. O tratamento tópico com emulsão anidra com 10% de IP e ácido úsnico (ACPU) mostrou redução a carga parasitária em Golden hamsters. Este estudo demonstrou a possibilidade de utilizar o tratamento tópico para reduzir o número de parasitas e que este poderia ser associado a outras drogas para tratamento mais rápido e eficaz da leishmaniose cutânea.(AU)

Microporous Hyper-Crosslinked Polystyrenes and Nanocomposites with High Adsorption Properties: A Review.

Hyper-crosslinked (HCL) polystyrenes show outstanding properties, such as high specific surface area and adsorption capability. Several researches have been recently focused on tailoring their performance for specific applications, such as gas adsorption and separation, energy storage, air and water purification processes, and catalysis. In this review, main strategies for the realization of HCL polystyrene-based materials with advanced properties are reported, including a summary of the synthetic routes that are adopted for their realization and the chemical modification approaches that are used to impart them specific functionalities. Moreover, the most up to date results on the synthesis of HCL polystyrene-based nanocomposites that are realized by embedding these high surface area polymers with metal, metal oxide, and carbon-based nanofillers are discussed in detail, underlining the high potential applicability of these systems in different fields.

Pure titanium particle loaded nanocomposites: study on the polymer/filler interface and hMSC biocompatibility.

The integration of inorganic nanoparticles into polymer matrices allows for the modification of physical properties as well as the implementation of new features for unexplored application fields. Here, we propose the study of a new metal/polymer nanocomposite fabricated by dispersing pure Ti nanoparticles into a poly(methylmetacrilate) matrix via solvent casting process, to investigate its potential use as new biomaterial for biomedical applications. We demonstrated that Ti nanoparticles embedded in the poly(methylmetacrilate) matrix can act as reinforcing agent, not negatively influencing the biological response of human mesenchymal stem cell in terms of cytotoxicity and cell viability. As a function of relative amount and surface treatment, Ti nanoparticles may enhance mechanical strength of the composite-ranging from 31.1 ± 2.5 to 43.7 ± 0.7 MPa-also contributing to biological response in terms of adhesion and proliferation mechanisms. In particular, for 1 wt% Ti, treated Ti nanoparticles improve cell materials recognition, as confirmed by higher cell spreading-quantified in terms of cell area via image analysis-locally promoting stronger interactions at cell matrix interface. At this stage, these preliminary results suggest a promising use of pure Ti nanoparticles as filler in polymer composites for biomedical applications.

Down shifting in poly(vinyl alcohol) gels doped with terbium complex.

Novel poly(vinyl alcohol) (PVA) based soft gels with luminescent properties are detailed in this contribution. Lanthanide complex of terbium ions with anthranilic acid, Tb(ant)3·2H2O, was synthesized and incorporated into a DMSO/water solution, followed by addition of PVA, to attain soft gels at room temperature. Morphological and thermal analyses revealed homogeneous distribution of Tb(ant)3·2H2O into the PVOH/DMSO/water gel, and that incorporation of the terbium complex does not alter the thermal properties of the gels. The gels are transparent and luminescent, as they exhibit Large Stokes shift down shifting (LSS DS) up to 400nm, with very high emission quantum yield, that was found to be function of Tb complex concentration.

Unilateral NMR investigation of multifunctional treatments on stones based on colloidal inorganic and organic nanoparticles.

Consolidation and protection are among the most important treatments usually carried out in conservation of stone artifacts and monuments. In this paper, portable unilateral NMR and conventional techniques were used for investigating new multifunctional treatments based on tetraethoxysilane, silica, and polytetrafluoroethylene nanoparticles. The study was carried out on a very complex and heterogeneous porous stone such as tuff. NMR study allowed to obtain detailed information on the penetration depth of treatments, the hydrophobic effect, and changes in the open porosity caused by treatments. Physical and chemical inhomogeneities between the impregnated layers of tuff and the layers underneath were also detected. The average pores radius and pores interconnection obtained from NMR diffusion measurements were used for the first time to compare effects of different consolidating and/or protective treatments on stone. Because unilateral NMR technique is neither destructive nor invasive, investigation of treatments can be also carried out and optimized directly on buildings and monuments of interest for Cultural Heritage.

Thermoreversible luminescent organogels doped with Eu(TTA)3phen complex.

This manuscript details the preparation and characterization of luminescent organogels in toluene. Gels were prepared by using 12-hydroxystearic acid (12HSA) as gelator and different amounts of thenoyltrifluoroacetonato 1,10-phenanthroline europium(III) complex (Eu(TTA)3phen). The gelation properties and the thermoreversible behavior from solid-like to liquid systems were investigated by differential scanning calorimetry. At higher concentration, an interaction of Eu complex with the polar group of the gelator was revealed by DSC and FTIR analyses. The spectroscopic behavior of the complex was investigated in toluene solution and in the gel state. TEM analysis revealed that 12HSA is able to solvate the Eu diketonate complex inducing a remarkable increase in the Eu-Eu distance. The Eu(TTA)3phen in the gel state exhibits a very high emission quantum yield, Φ, which was found to be independent of Eu complex concentration, at least for the composition range analyzed. These results indicate that 12HSA organogels containing Eu(TTA)3phen are promising materials for optical applications.

Development of nanocomposite based on hydroxyethylmethacrylate and functionalized fumed silica: mechanical, chemico-physical and biological characterization.

In this research work organic/inorganic nano composites were synthesized from poly-2-hydroxyethylmethacrylate and properly modified silica nanoparticles by in situ polymerization. In particular, fumed nanosilica was functionalized with methacryloylpropyltrimetoxy silane (MPTMS) in order to obtain a more homogeneous, reliable and mechanically performing nano composite. For comparison, nano composites with non functionalized silica were also prepared. Scanning electron microscopy was performed in order to visualize the effects of functionalization on the mode and state of dispersion. This analysis demonstrated that MPTMS grafted onto silica surface acts as an effective coupling agent and assures a good dispersion and distribution of nanoparticles as well as a strong nano particle/matrix interfacial adhesion. As a result of strong interactions occurring between phases, a pronounced increase of the glass transition temperature and mechanical parameters were recorded. Finally, these novel nano composites were seeded with murine fibroblast and human mesenchymal stem cells, and observed in time-lapse experiments proving an effective biological response.