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Currently, an important ecological problem is environmental pollution and its negative impact on living organisms, the consequences of which are deterioration in general health and the manifestation of various diseases, poisoning, endo- and exotoxicosis. Enterosorption method was proposed as a promising method for removing toxic substances from the living organisms using enterosorbents which can absorb various toxic substances of endogenous and exogenous nature in the lumen of the gastrointestinal tract. It has been proposed to use polymer-containing enterosorbents for eliminating of heavy metals from the organism. The purpose of this research was to synthesize a quaternized derivative of chitosan, specifically N-(2-hydroxybenzyl)-N-ethyl-N-methyl chitosan chloride (Q-CHS). The synthesis of Q-CHS involved the formation of a Schiff base, followed by the quaternization of the amino group of chitosan (CHS). The structures of both pure CHS and quaternized CHS were studied using various physico-chemical methods, including FTIR, NMR, XRD, SEM, DSC and TGA analyses in order to determine the structure and confirm the formation of the final product. [Display omitted] • Search and development of new effective, easily accessible, harmless and improved compositions of enterosorbents (for removing toxic substances from the living organisms in the lumen of the gastrointestinal tract) is a topical question today. • Chitosan, containing reactive functional (amino and hydroxyl) groups, can be subject to various modifications in order to improve certain properties and, thus, can find wide application. • Quaternized chitosan was successfully synthesized with the purpose to use it in future as an enterosorbent. [ABSTRACT FROM AUTHOR]

• UV-induced degradation lowers the corrosion inhibitor ability of benzotriazole. • Mesoporous silica nanocarriers protect benzotriazole from photodegradation. • High anticorrosion efficacy of nanocomposite coatings even after UV exposure. Corrosion inhibitors are largely exploited for the development of highly performing polymeric active coatings. One of the major drawbacks, however, relies in their UV sensitivity, which may compromise their ability to effectively prevent corrosion processes. This issue is particularly relevant in the field of cultural heritage preservation, in which polymeric active coating which are able to ensure a reliable and long-lasting protection against corrosion are highly needed. Besides proving that UV-induced photodegradation impressively lowers the corrosion inhibition ability of benzotriazole (BTA), in the present work we show that this phenomenon can be largely prevented by exploiting inorganic nanocarriers. More specifically, BTA molecules loaded into functionalized mesoporous silica nanoparticles are preserved from photodegradation and released in the host coating only in the presence of acid-related external stimuli. Accelerated corrosion tests carried out on a commercial acrylic-based coating containing engineered mesoporous silica nanoparticles loaded with BTA demonstrated that the developed system possesses an excellent anticorrosion ability. [ABSTRACT FROM AUTHOR]

Mesoporous silica nanoparticles are among the most promising nanovectors for controlled release of active compounds. In this work we design a mesoporous silica-based delivery system in which the release of the active compound is controlled by specific pore/wall interactions and can also be triggered by an external stimulus, such as the simple addition of water into the surrounding releasing medium. Due to its reversibility in presence of water, imine bond formation between amino groups and aldehydes has been proposed as a valuable approach to reach this scope. The amino-group is provided by the amino-functionalized mesoporous silica which has been obtained through the functionalization of Santa Barbara Amorphous (SBA)-15 with aminopropyltrietoxysilane. Whereas the aldehyde is represented by the active compound itself: the natural antimicrobial vanillin. The obtained particles have been embedded into PCL-based films. The amino-functionalization of mesoporous silica has been confirmed through NMR analysis and X-ray diffraction. Imine bond formation and evolution has been followed by 13 C NMR before and after the contact of mesoporous silicas with water. Release kinetics of vanillin show that the diffusion of vanillin from films containing the functionalized mesoporous silica is delayed by about 20% and 75% with respect to films containing free vanillin, in water and in ethanol respectively. The most significant feature of the system is the stepwise behavior which shows that the release of the amount of vanillin bound to the NH 2 groups of functionalized SBA is triggered only after the addition of water to the surrounding ethanolic solution. These findings give an important insight into the use of pristine and functionalized mesoporous silicas for the development of polymer films for active responsive packaging materials. [ABSTRACT FROM AUTHOR]

Highlights: [•] AgMMT nanoparticles obtained by ion exchange reaction were embedded into chitosan film. [•] Water uptake of the chitosan/AgMMT films is lower than neat chitosan. [•] Active bionanocomposites were effective after 24h. [ABSTRACT FROM AUTHOR]

Abstract: Effects of high pressure (HP) pasteurization and sterilization processes on the properties of commercial biodegradable polylactic acid (PLA), used as packaging material, have been investigated. HP treatments have been performed at pressures of 200, 500 and 700MPa on PLA pouches, containing different types of food, i.e. tap water, solid carrots, carrot juice and carrot puree. Process temperature was in the ranges 25–40 and 90–110°C, respectively for HP pasteurization and HP sterilization. To the aim of assessing the suitability of PLA film for HP treatment of packaged food, the effects of treatments have been analyzed in terms of structural/morphological changes (i.e. crystallinity, density, orientation of PLA film) and of thermodynamics and functional properties (i.e. melting and glass transition temperature, permeability and solubility of gases and of water vapor). It has been found that HP pasteurization does not affect to a significant extent any structural and functional property of the treated material relevant for food packaging applications. Conversely, HP sterilization promotes the hydrolysis of the material accompanied by an increase of crystallinity of the film and a decrease of density of the amorphous phase related to the temperature/pressure history. These effects determine an unacceptable embrittlement and opacification of the material that makes it unsuitable for HP sterilization applications. [Copyright &y& Elsevier]

Abstract: Objective: The effect of a novel light curing process, namely soft light energy release (SLER ®), on shrinkage, mechanical strength and residual stress of four dental restorative materials (DEI experience, Gradia Direct, Enamel Plus HFO and Venus) was investigated. Methods: Composite specimens were fast cured through high level of power density and soft light energy release. Temperature, linear shrinkage and light power measurements were acquired in parallel in order to assess the effect of light modulation on temperature and shrinkage profiles during the light curing process and the following dark reaction phase. The small punch test and Raman spectroscopy were adopted to investigate the effect of SLER ® on mechanical strength and on internal stress, respectively. Results: The soft light energy release photo-polymerization allows to reduce of about 20% the shrinkage rate and to increase the strength of fast light cured specimens. In addition, a more relaxed and homogeneous internal stress distribution was observed. Significance: Properties of fast cured restorative materials can be improved by adopting the soft light energy release process. [ABSTRACT FROM AUTHOR]