The aim of the present paper is to investigate the properties of three binary systems based on 2% w/v sodium alginate (AlgNa) and 3% w/v starch, prepared by means of a magnetic stirrer. 3% w/v n-clay was added over the binary mixtures, while the amount of n-clay to all mixtures was 1.5% and 3%, respectively. Microspheres were obtained by crosslinking the prepared mixtures with 1.5 M CaCl 2 ·2 H 2 O. The resulted composites were evaluated in terms of surface morphology (scanning electron microscopy -SEM), elemental composition (energy dispersive X-ray -EDX), swelling, thermal analysis (differential scanning calorimetry -DSC), electrochemical surface properties (zeta potential) and batch adsorption-desorption. The obtained results evidenced that the tested alginate/starch/n-clay 1/2/3 composite has the most promising properties for a biomaterial with potential applications in recovery of Cu(II) from polluted water.

The present paper reported the obtaining of an environmental friendly adsorbent based on sodium alginate, chitosan and glass bubbles. CaCl2 was used as crosslinking agent for sodium alginate favoring the interactions by physical bonds between the negative groups (-COO) of biopolymer and the Ca ions. The experimental study to determine the Cu(II) uptake using an atomic absorption spectrometer was conducted in the testing stand at the 1:50 and 1:100 ratios between the adsorbent mass and the amount of pollutant in solution. The number of cycles of regeneration of the adsorbent material was also evaluated. The characterization of alginate/chitosan/glass bubbles adsorbent by scanning electron microscopy (SEM) coupled with energy dispersive spectrometer (EDS) and Fourier transform infrared spectroscopy (FTIR) showed that the Cu(II) was found out on the surface of adsorbent.

A sodium alginate/cellulose/n-clay composite was prepared as potential adsorbent for removal of Pb(II) from wastewater. The results showed that obtained adsorbent used for 4 mg L-1 initial concentration of Pb(II) in wastewater after 90 min adsorption time led to 90% removal efficiency and the adsorption capacity of the prepared composite was 0.11 mg .g-1. The isotherms and kinetics of adsorption revealed that the equilibrium adsorption and kinetics were well-described by the Langmuir model and pseudo-second-order kinetics, respectively.

We present the studies carried out on the transport properties of some membranes obtained from synthetic polymers: polyurethane and ethylene-vinyl acetate copolymer, for use in the development of transdermal therapeutic systems with limiting membranes of speed. The properties of drug active substances transport through membranes were highlighted by performing studies with a diffusion cell. Experimental drug active substances were paracetamol and tetracycline. The experimental data obtained was processed using a general mathematical model for drug release from non-porous, non-swellable transdermal devices, which starts from Fick�s second law and has terms that also take into account the possibility of retaining the drug in the membrane polymer. Even though the mathematical model does not take into account neither the swelling phenomenon nor the possibility of membrane erosion, a good agreement between model and experimental data was obtained. The values of effective diffusion coefficients of drug in the polymeric membranes were also determined.

Lemon balm (Melissa officinalis L.) belongs to the Lamiaceae family. Essential oil extracted from the aerial parts of lemon balm has been investigated for the protection of fruits during storage, as insecticidal, as well as in medicine, due to its bioactive properties. In this paper, the composition and identification of components from Melissa officinalis L. essential oil were determined by gas chromatography coupled with mass spectrophotometry (GC/MS) analysis. Total phenol content (TPC) and the scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH·) and 2,2′-azino-bis (3-ethylbenzthiazoline)-6-sulfonic acid (ABTS+·) free radicals were evaluated by UV-VIS spectrometry. Antibacterial activities were carried out against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Seventeen bioactive compounds were found as constituents of Melissa officinalis L. essential oil, among which o-cymene (19.735%), dehydro-p-cymene (17.180%), and limonene (11.589%) were found as the major components. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR) provided a confirmation for the chemical components of lemon balm essential oil identified by GC/MS. The values recorded for TPC and antioxidant activity were as follows: 54.72 mg GAE/g dry substance, 28.53% for DPPH, and 46.17% for ABTS assays, respectively. 100 µL lemon balm essential oil proved total antibacterial activity against the tested microorganisms. The results showed that the Melissa officinalis L. may be a good candidate as plant-derived antioxidant and antibacterial agent for medical footwear, wound dressings and other medical applications.