New method to increase pesticide deposition: Copper microencapsulation

Copper plant protection products have been severely restricted in the EU according to soil and groundwater contamination due to the traditional use as a fungicide, especially in vineyards. This limitation, together with the dependence on copper use for mildew control, places winegrowers in a great disadvantage, especially in organic production. Therefore, EURECAT together with the UPC, have developed a new copper product, more efficient in terms of deposition, in order to reduce the amount of active ingredient necessary for good disease control. Preliminary trials have been carried out by the UPC, in order to select the best formulation and to compare it with a conventional copper-based product in terms of deposition using filter paper as a collector in an artificial vineyard. The obtained results show that deposition of different developed products is statistically different from the control product, even doubling the amount of copper deposited in the collectors, which would be a promising solution to solve the problem outlined above.The presented research is part of the COPPEREPLACE project (INTERREG SUDOE, Ref. SOE4/ P1/E100) in the frame of the activity 3.3 in the GT3.Postprint (published version

Formulation of Microbial Inoculants by Encapsulation in Natural Polysaccharides: Focus on Beneficial Properties of Carrier Additives and Derivatives

In the last 10–15 years, the wide application of bioformulated plant beneficial microorganisms is accepted as an effective alternative of chemical agro-products. Two main problems can be distinguished in their production and application: (a) economical competiveness based on the overall up-stream and down-stream operational costs, and (b) development of commercial products with a high soil-plant colonization potential in controlled conditions but not able to effectively mobilize soil nutrients and/or combat plant pathogens in the field. To solve the above problems, microbe-based formulations produced by immobilization methods are gaining attention as they demonstrate a large number of advantages compared to other solid and liquid formulations. This mini-review summarizes the knowledge of additional compounds that form part of the bioformulations. The additives can exert economical, price-decreasing effects as bulking agents or direct effects improving microbial survival during storage and after introduction into soil with simultaneous beneficial effects on soil and plants. In some studies, combinations of additives are used with a complex impact, which improves the overall characteristics of the final products. Special attention is paid to polysaccharide carriers and their derivates, which play stimulatory role on plants but are less studied. The mini-review also focuses on the potential difficulty in evaluating the effects of complex bio-formulations.This work was supported by the project EXCALIBUR funded from the European Union’s Horizon 2020 Research and Innovation Program under grant agreement No. 817946

Alternatives to CU Applications in Viticulture. How R&D Projects Can Provide Applied Solutions, Helping to Establish Legislation Limits

Copper (Cu) and its based preparations have been used for over 200 years to control fungi and bacterial diseases in cultivated plants. Downy mildew caused by the obligate biotrophic oomycete Plasmopara viticola is one of the most relevant and recurrent diseases of grapevines. Recently, the use of Cu is being limited by some regulations because of its high impact at different levels (health and environmental problems). Due to its accumulation in soil, this metal causes a little controversy with the principles of sustainable production. Therefore, international legislation and initiatives have recently been arisen to start limiting its use, with the main goal to replace it. In this framework, some alternatives have been tested and others are recently being developed to replace, at least partially, the use of Cu in viticulture. Many of them, are being developed and tested under the scope of research and development EU funded projects. To not compromise sustainability targets in viticulture, results from these R&D projects need to be considered to assess the present risks of using Cu in viticulture and to better support establishing limits for its applications, considering soils vulnerability, while no sustainable alternatives are available in the market

Polymer Engineering

Polymer Engineering focuses on the preparation and application of polymers in several hot topics such as artificial photosynthesis, water purification by membrane technologies, and biodiesel production from wastewater plants. The authors not only describe the latest developments in polymer science, but also support these experimental results by computational chemistry and modelling studies

Controlling the Skin Barrier Quality through the Application of Polymeric Films Containing Microspheres with Encapsulated Plant Extract

Human skin has protective functions and it is a barrier that protects the interior of the body from harmful environmental factors and pathogen penetration. An important role of the skin is also to prevent the loss of water from the body and if the skin barrier is damaged, the amount of water emitted from the internal environment is increased. Therefore, it is crucial to recovery and maintenance of epidermal barrier integrity. The aim of the current work was to encapsulate Calendula officinalis flower extract in gelatin microspheres and then incorporation microspheres into thin polymeric films made from sodium alginate or mixture of sodium alginate and starch. Such materials may find applications in the cosmetic field for example in the preparation of masks for skin, according to the Calendula officinalis flower extract wide influence on skin condition. Thus, the release profile of this extract from the materials was tested under conditions corresponding to the skin (pH 5.4, 37 °C). The mechanical properties, surface free energy, and moisture content of obtained films were measured. To determine the barrier quality of the stratum corneum, transepidermal water loss (TEWL) and skin color measurements were performed. The loaded microspheres were successfully incorporated into polymeric films without affecting its useful properties. Although the values of Young’s modulus and the moisture content were decreased after film modification by microspheres addition, the skin parameters were much better after application of films with microspheres. The results confirmed that obtained materials can be potentially used in cosmetics to improve the skin barrier quality

Light-Responsive Polymer Micro- and Nano-Capsules

A significant amount of academic and industrial research efforts are devoted to the encapsulation of active substances within micro- or nanocarriers. The ultimate goal of core–shell systems is the protection of the encapsulated substance from the environment, and its controlled and targeted release. This can be accomplished by employing “stimuli-responsive” materials as constituents of the capsule shell. Among a wide range of factors that induce the release of the core material, we focus herein on the light stimulus. In polymers, this feature can be achieved introducing a photo-sensitive segment, whose activation leads to either rupture or modification of the diffusive properties of the capsule shell, allowing the delivery of the encapsulated material. Micro- and nano-encapsulation techniques are constantly spreading towards wider application fields, and many different active molecules have been encapsulated, such as additives for food-packaging, pesticides, dyes, pharmaceutics, fragrances and flavors or cosmetics. Herein, a review on the latest and most challenging polymer-based micro- and nano-sized hollow carriers exhibiting a light-responsive release behavior is presented. A special focus is put on systems activated by wavelengths less harmful for living organisms (mainly in the ultraviolet, visible and infrared range), as well as on different preparation techniques, namely liposomes, self-assembly, layer-by-layer, and interfacial polymerization

Ambient CO2 adsorption via membrane contactors – Value of assimilation from air as nature stomata

Biomimetic systems represent one of the most attractive ways to produce artificial complex devices taking the best from nature in a simple and repetitive manner. Some of these systems can imitate trees in some of their functions, in this article, the objective is to imitate trees in their ability to fixate CO2 and use it to produce organic compounds. As trees do that fixation after the penetration of the gas though the smart pores of the leaves, stomata, we call our pores as artificial stomata. The project aims to end up with compact systems for small size devices that would work with autonomy in the near future in energy systems. Polysulfone based membranes were prepared by a Phase Inversion Precipitation method using different polymeric solutions (N,NDimethylformamide or 1-Methyl-2-pyrrolidone). Obtained asymmetric fingerlike, droplike, or spongy morphologies were characterized: by SEM and ESEM equipped with EDX, while their surfaces were investigated by: AFM, dynamic and static contact angle, swelling measurement. Moreover, copper - ferrite nanoparticles, used for preparation of composite membranes was characterized by TEM, and X-ray diffraction. Their influence on material CO2 solubility, membrane surface morphology and wettability were deeply investigated, and demonstrated influence of membranes roughness on their performance. Furthermore, generated results reveled higher CO2 assimilation than the natural stomata and shown very high CO2 absorption flux (67.5 mmol/m2*s)

The Effect of pH on the Size of Silver Nanoparticles Obtained in the Reduction Reaction with Citric and Malic Acids

In colloidal methods, the morphology of nanoparticles (size and shape) as well as their stability can be controlled by changing the concentration of the substrate, stabilizer, adding inorganic salts, changing the reducer/substrate molar ratio, and changing the pH and reaction time. The synthesis of silver nanoparticles was carried out according to the modified Lee and Meisel method in a wide pH range (from 2.0 to 11.0) using citric acid and malic acid, without adding any additives or stabilizers. Keeping the same reaction conditions as the concentration of acid and silver ions, temperature, and heating time, it was possible to determine the relationship between the reaction pH, the type of acid, and the size of the silver nanoparticles formed. Obtained colloids were analyzed by UV-Vis spectroscopy and investigated by means of Transmission Electron Microscope (TEM). The study showed that the colloids reduced with citric acid and malic acid are stable over time for a minimum of seven weeks. We observed that reactions occurred for citric acid from pH 6.0 to 11.0 and for malic acid from pH 7.0 to 11.0. The average size of the quasi-spherical nanoparticles changed with pH due to the increase of reaction rate

Visible light triggered microcapsules

Microcapsules are small particles which contain an active agent or core material surrounded by a coating or shell. 1 The utility of microcapsules for efficient cargo storage and targeted release is of considerable importance in self-healing materials, nutrient preservation, agricultural applications, fragrance release, and drug delivery. 2 One of the most challenging tasks and the ultimate purpose of developing delivery systems are to modulate the release of encapsulated cargo substances. Strategies such as heat treatment, pH change, magnetic fields and light-induced morphology change have been used to alter the shell density and integrity, and then to influence capsule permeability. 3-5 As one of the most interesting parts of stimuli-responsive capsules, photo-stimuli responsive capsules are capable of affecting their micro-/nano-structures in the form of remote control triggered by external light e.g., sun light, without requirement of direct contact or interactions. Moreover, triggering the release of microcapsules by light has a number of advantages over other external stimuli: light does not contaminate the reaction systems; the excitation wavelength can be controlled through the design of the photo-responsive molecule, it is easy to control the time and/or local excitation.6-9 The development of such highly light sensitive vesicles is of great importance, especially in the fields of surface sciences and environmental applications, where sometimes light would be the only available stimulus to drive the systems. Our aim was first to synthesize and characterize visible light sensitive monomer: 4,4’-bis(chlorocarbonyl)-2,2’-dimethoxy azobenzene and then, based on it, photo-triggered microcapsules containing a perfume oil as a core material. These microcapsules were obtained by oil-in-water interfacial polymerization reaction. In this communication we present preliminary results of microcapsules preparation, characterization and controlled perfume release, by means of different techniques (OM, SEM, Light scattering, GCMS). Financial support from European Community\u27s Seventh Framework Programme, under IOF Marie Curie grant agreement no. 328794 is gratefully acknowledged

Preparation and Characterization of Light-Sensitive Microcapsules Based on a Liquid Crystalline Polyester

Photosensitive microcapsules and membranes based on poly­(α-methylstilbenesebacoate-co−α–methylstilbeneisophthalate), containing the photosensitive α-methylstilbene moiety, were prepared by a phase-inversion precipitation process. In order to simulate the morphology and behavior of the microcapsule shell under UV irradiation, an exhaustive characterization of a membrane was first performed by ESEM, POM, AFM, and contact angle measurements. The prepared microcapsules contained either chloroform or a concentrated solution of vanillin in chloroform as the core; in all cases, before UV irradiation, their outer surface appeared smooth and dense. The influence of vanillin on microcapsule cross-section morphology was observed by ESEM microscopy. Release of vanillin in water, at room temperature, was markedly influenced by UV irradiation: in the absence of irradiation, it was practically negligible, while when microcapsules were submitted to continuous irradiation with UV light, the surface morphology of the capsules changed drastically and vanillin started to be released after ca. 20 min of irradiation