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Molecularly imprinted polymer (MIP) beads for proto-hypericin recognition were prepared by suspension polymerization. In order to study the impact of monomers on the MIPs properties, various monomers such as acrylic acid (AA), hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA) and itaconic acid (IA) in their combinations were crosslinked with ethylene glycol dimethacrylate (EDMA) in the presence of a complex phyto-extract template derived from Hypericum perforatum L. The synthesized MIPs and corresponding non-imprinted polymers NIPs were characterized by infrared spectroscopy analysis, morphology and thermogravimetric analysis. High-performance liquid chromatography combined with UV-Visible spectroscopy, used to investigate the recognition properties of the MIPs for various naphthodianthrones, pointed out that the MIP IA-AA system seemed to be the most adequate for favoring quantitative rebinding of proto-hypericin and proto-pseudohypericin against competitors with similar structures, like hypericin and pseudo-hypericin, which are usually present in high quantities in the primary Hypericum perforatum L. phyto-extracts.

New nanogels (NGs) with tailored properties were obtained using a mini-emulsion technique, from poly(ethylene glycol) diacrylate (PEGDA) self-crosslinking macromers of various molecular weight. By modifying synthesis parameters (hydrophilic-lipophilic balance, emulsifier and the ratio of organic-aqueous medium), optimum recipes of NGs were selected. Therefore, the molecular weight distribution and the functionalization degree of the PEGDA2000 macromer were assessed by Gel Permeation Chromatography (GPC) and Nuclear Magnetic Resonance (NMR), respectively. Furthermore, the PEGDA-NGs were investigated by Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM) for size distributions and morphology. DLS and TEM results confirm that these new PEGDA-NGs hold potential for biomedical applications.

Hypericum perforatum L., traditionally called St. John�s Wort has been used for decades as a phyto-therapeutic herb due to antidepressant, antimicrobial and antiseptic properties. As a result, the presented study evaluates the influence of the harvesting season for the Hypericum perforatum L. plant material, which is crucial for obtaining significant amounts of active principles.

In this study, composite hydrogels with interpenetrated polymer networks (IPNs), based on bacterial cellulose (BC) and poly(acrylic acid-co-N,N′-methylene-bis-acrylamide) (PAA), were synthesized by radical polymerization and characterized herein for the first time. Liquid fertilizer (LF) formulations, containing potassium, phosphorus, ammonium oxides and micronutrients, were encapsulated directly into the IPNs of the composite hydrogels during synthesis. Thermal analyses and scanning electron microscopy of control and composite xerogels highlighted the formation of IPNs between BC and PAA. Swelling determinations confirmed the influence of the crosslinker and of the liquid fertilizer concentration upon the density of the IPNs. Further rheology studies and release profiles indicated how the presence of BC and the increase of the crosslinking density of IPNs improved the mechanical strength and the release profile of LF for the innovative composite BC-PAA hydrogels. Results regarding the fertilizer release indicated that the presence of the BC led to a more controlled liberation of the fertilizer proving that this new formulation is potentially viable for application in agricultural practices.

In this study, TiO 2 films were successfully grown in-situ onto a FTO substrate by a hydrothermal method, using TiCl 4 as Ti precursor, and further on functionalized with a 2,4,6-trinitrotoluene-molecularly imprinted polymer (TNT-MIP) film as a preliminary step in developing a trinitrotoluene (TNT) reusable sensor to overcome the international security issues. For investigating the TiO 2 film thickness, crystalline structure and morphology, the films were autoclaved at 200 °C at different times. The X-ray diffraction showed that TiO 2 films possessed a rutile structure, with no cracks visible by atomic force microscopy (AFM), and the films morphology observed by scanning electron microscopy (SEM) was highly dependent upon the hydrothermal treatment time. Yet, the TiO 2 films with a more porous surface were more suitable for TNT-MIP film deposit. Rheology of precursor polymer film solutions, based on poly (acrylonitrile- co -acrylic acid), poly (acrylonitrile- co -methacrylic acid) or poly (acrylonitrile- co -itaconic acid), and the structure and adherence of TNT-MIP films were investigated in order to establish the correct recipe of the MIP. The removal yield of TNT from the imprinted films, the thickness, the porosity and the compatibility with the inorganic TiO 2 film were adequate for the poly (acrylonitrile- co -acrylic acid) system with an acrylonitrile: acrylic acid practical ratio of 86.1:13.9 (wt./wt.). Farmore, AFM morphology corroborated with SEM results highlighted the effect of TNT imprinting in the copolymer matrix as the surface of the imprinted layer was quite different from that of the non-imprinted layer.

This paper debates the effect of the stabilizer (vinyl benzyl trimethyl ammonium chloride—VBTAC or cetyl trimethyl ammonium chloride—CTAC) and the structure (typical SiO2 matrix or inorganic–organic interpenetrated matrix) influence in molecular imprinting of gallic acid-polyphenol class of templates. For this purpose, gallic acid-imprinted particles were obtained via typical polycondensation sol–gel reactions and via sol–gel/radical polymerization concurrent reactions of tetraethoxy silane (TEOS) and aminopropyl ethoxy silane (APTES) or vinyl triethoxy silane (VTES), respectively. The influence of the mesophase formation and stabilizer nature upon the re-binding of gallic acid was investigated using thermal, infrared and morphology measurements. Adsorption assays of organosilica particles were well correlated with their physical properties. Unlike the polycondensation of TEOS with APTES in the presence of CTAC, concurrent radical polymerization of VBTAC consumed the vinyl functionalities of VTES, decreasing the capacity of VBTAC to mediate the mesophase formation and the capacity of VTES to coordinate template molecules; hence, both the binding capacity and the “memory” effect of the interpenetrated organosilica structure were significantly affected.

The present paper was aimed at studying the possibility of zinc (Zn) removal from the wastewater discharged from zinc electroplating processes. In order to save industrial and environmental resources, the concentrated solution could be reused after electrodialysis process. A mini-electrodialysis system with three cylindrical compartments and different membranes containing various resins (Purolite A500 and Hypersol-Macronet MN500) was employed, which can be further applied for the treatment of synthetic effluent which contained zinc ions. The electrodialysis system was operated at constant voltage using different concentrations of synthetic solutions of zinc ions, without and with electrolyte recirculation for 1.5 h. The pH and conductivity of solutions were measured before and after the electrodialysis process occurs. Also the removal ratio (Rr) and mass flow (J) of zinc ions, energy consumption (EC) and current efficiency (CE) were determined. It was found that electrodialysis treatment generated a very low conductivity solution, enabling its reuse as rinse water. According to the obtained results when using a membrane pair with higher ion exchange capacity (IEC) the removal ratio is improved (over 80%). The physico-chemical, structural and mechanical properties of prepared membranes were registered, before and after electrodialysis process takes place, by means of complementary analytical techniques, namely, ion-exchange capacity, water content and thickness measurements. Furthermore analysis were also carried out by Fourier transform infrared spectroscopy (FT-IR), environmental scanning electron microscopy (ESEM), thermal gravimetric analysis (TGA) and electrochemical impedance spectroscopy (EIS).

The host–guest radical polymerization of vinyl acetate in the inorganic porous matrix improved both, thermal and mechanical properties of final modified material, relative to the polymer alone, which can be further used for various applications where stability in aggressive environments is required. The bulk material was characterized by various techniques i.e. elemental analysis, X-ray photoelectron spectroscopy (XPS), gel permeation chromatography (GPC), thermal gravimetric analysis (TGA), dynamic mechanical analysis (DMA), scanning electron microscopy (SEM) and porosity measurements (BET). XPS measurements indicated a preferential order of acetate groups at the surface of the hybrid and BET analyses highlighted the formation of a new porous structure derived from the mesoporous inorganic host. GPC results of the polymer extracted from the zeolite matrix showed variations of molecular weight and low polydispersity index relative to the pure polymer, which could be a consequence of a controlled polymerization mechanism induced by the presence of metal ions found in the zeolite matrix. Thermal stability and elasticity of the restrained polymer compared to that of pure PVAc was notably enhanced. Char formation in the sixth degradation stage and demethylation were additional steps compared to PVAc alone indicating some modifications of the thermal degradation mechanism for the entrapped PVAc.

A facile and inexpensive approach was established to prepare spherical molecularly imprinted polymers with hypericin (H-MIPs) via the wet-phase inversion method. The H-MIPs were characterized by infrared spectroscopy and thermogravimetric analysis. High-performance liquid chromatography combined with UV-Visible spectroscopy were used to assess the efficiency of the extraction procedure and, furthermore, to investigate the recognition properties of the H-MIPs. Obtaining an imprinting factor of 3.38 for hypericin strongly indicated a successful formation of molecularly imprinted cavities onto the H-MIPs. A fair selectivity towards hypericin was tested in comparison to the interfering molecule pseudohypericin.

St. John s Wort (SJW) or Hypericum perforatum L. is a therapeutic plant highly used in pharmacology. Recent in vivo anti-cancer action of naphtodianthrones (NTs) has extended the research related to enrichment methodologies of SJW phyto-extracts. Therefore, the presented study pursuits the optimization of single-step extraction methodologies to obtain NTs-rich extracts from SJW.

In this work, a synthetic effluent containing Methylene blue dye has been treated by novel membrane enriched with commercial gooseberry buds extract using a mini-laboratory electrodialysis cell. The electrodialysis system was operated at various time and constant voltage applied at electrodes. Methylene blue removal percentage (CR %) and energy consumption (E.C.) were calculated. The obtained results showed that pH increase in solution and lead to an increase of deprotonated methylene groups, which may favor methylene dichloride complex formation. The values of CR % and E.C. increased with time. The high value of CR % was obtained at 60 min(CR] 89 %). The membranes were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Environmental Scanning Electron Microscopy (ESEM).