2018, Volume 64(68), Issue 1 (March)

Contents

pages 1- 8    Download

TG/MS/FTIR Study of Thermal Decompositions of Some Baby Teats

ANDREEA MIHĂILĂ, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
MĂDĂLINA MACOVEI, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
LĂCRĂMIOARA MAIECZKI, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
MARINA VODUŢ, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
NIŢĂ TUDORACHI, "Petru Poni" Institute of Macromolecular Chemistry, Iași, Romania
GABRIELA LISĂ, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, gapreot@ch.tuiasi.ro

pages 9 - 18    Download
Abstract
Our research consisted of the determination of the mass losses and degradation products in gaseous state obtained further to the analysis of teats used for the feeding of babies by means of the TG/MS/FTIR technique. The TG curve profiles are similar in the teats made of silicone rubber, the resulting residue amounting to 57%. The teat made of latex is almost fully degraded, the resulting amount of residue being only 0.5%. The analysis of the MS spectra obtained at 371°C temperature has provided information of the main ionic fragments resulting during the thermal decomposition onset stage. The findings were also confirmed by the FTIR spectra recorded for the same temperature. Our research also confirmed the presence of Bisphenol A in one of the two teats made of silicone rubber.
Keywords: thermal decompositions; TG/MS/FTIR; baby teats; Bisphenol A.

Azo-Polymers – Photocromic Behaviour Studies

CRISTINA-MARIA HERGHILIGIU, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, c_paius@ch.tuiasi.ro
IRINA CÂRLESCU, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
DAN SCUTARU, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
NICOLAE HURDUC, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection

pages 19 - 32    Download
Abstract
Understanding the response to illumination at molecular level and characteristics of azo-materials features the key to new bio-science applications and not only. Although a number of mechanisms have been proposed, the entire process of forming structured surfaces is not yet fully elucidated. For a better understanding of the nanostructuration process, the irradiation studies of azo-polymeric films were performed only in condensed phase. Response rate evaluation of azo-polysiloxanic materials to light stimuli, respectively the determination of the cis-trans equilibrium value were carried out at different radiation intensity values to highlight the phenomena occurring both at the surface and in the film depth, within photoinduced patterning processes. Films were irradiated in UV and VIS field. Results indicate that photochemical response of the azo-material is different depending on its chemical structure, irradiation wavelength, irradiation intensity value and the film thickness.
Keywords: azo-polysiloxanes; UV/Vis irradiation; photoisomerization; bulk film.

Preliminary Assessments About the Sorbtive Properties of New Types of Tempo-Oxidized Cellulose and Pullulan - PVA Hybrid Hydrogels: Organic Dyes and Metallic Ions Retentions

IULIA NICA, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
RALUCA IOANA BARON, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iași, Romania
GABRIELA BILIUȚĂ, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iași, Romania
SERGIU COȘERI, "Petru Poni" Institute of Macromolecular Chemistry of Romanian Academy, Iași, Romania
DANIELA ȘUTEU, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, danasuteu67@yahoo.com

pages 33 - 42 Download
Abstract
Polyvinyl alcohol (PVA) is a biodegradable polymer, largely used in the last years for the production of biodegradable hybrid materials, as a substitute of traditional polyethylene or polypropylene polymers. These materials have proved beneficial applications in water filtration, paper industry, mats and films production, and packaging. However, the PVA itself suffer of poor mechanical strength, requiring other components able to improve this property. Thereby, we propose the use of various amounts of natural polymers, i.e. cellulose and pullulan, in the form of C6 oxidized derivatives, as multifunctional key components, acting both as cross-linking agents, but also increasing the strengthening and stiffness properties of the as prepared hybrid PVA hydrogels. Therefore, several hybrid PVA hydrogels, with different amounts of incorporated polysaccharide (PVA-5P, PVA-10P, PVA-25P; PVA-5C, PVA-10C and PVA-25C) were synthesized and tested as sorbents for two models of dyes (Orange 16 and Methylene Blue) and Co2+ as metallic ions.
Keywords: hydrogels; cellulose; pullulan; dyes; metallic ions; sorbent.

Changes in Soil pH Due to The Use of Chemical Fertilizers

RAMONA-ELENA TĂTARU-FĂRMUȘ, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
ROXANA GEORGIANA COCEA, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
ANCA ADOMNICĂ, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
NICOLAE APOSTOLESCU, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, napostol@ch.tuiasi.ro

pages 43 - 50 Download
Abstract
Although soil is commonly referred to as "fertile substrate", not all soils are favorable for crop cultivation. Soils ideal for agriculture are balanced in terms of mineral, organic, air and water. Each of these factors plays a direct role in obtaining a good quality soil for agriculture. Soil pH is a very important element to be known because it occurs in many physicochemical and biological soil mechanisms. Optimal soil pH range for plant growth varies from one crop to another. Generally, soil pH 6.0-7.5 is acceptable for most plants like most nutrients are available in this pH range. The use of mineral fertilizers, although beneficial and imperative to obtain good qualitative and quantitative crops, changes the soil pH. The present paper proposes a laboratory study on changes in pH caused by the use of mineral fertilizers such as urea, ammonium nitrate, NPK complex fertilizer, combinations of these, with or without the addition of calcium carbonate - as an amendment. The research has revealed the direct link between the use of fertilizers and the modification of soil pH values.
Keywords: chemical fertilizers; NPK; soil pH; urea.

Comparative Study of Alginate Extraction Methods from Red Marine Algae Callithamnion Corymbosum Sp.

ALINA-ROXANA LUCACI, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection
LAURA BULGARIU, "Gheorghe Asachi" Technical University of Iași, Romania, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, lbulg@tuiasi.ro

pages 51 - 60 Download
Abstract
In recent years studies related to the metal ions biosorption on biological materials have increased significantly. Unfortunately, the relatively low biosorptive performances of most of natural biomasses have determined the finding of simple and cheap methods for the separation of various compounds from biomass composition, which are more efficient in the biosorption processes. Alginate is an active compound found in marine algae, and which is a great interest in environmental engineering. In this study are adapted and compared two methods for alginate extraction using red algae biomass (Callithamnion corymbosum sp.) as raw material. The main advantages and disadvantages of each extraction procedure are highlighted, in order to provide the best way to extract the alginate from marine algae biomass. Also, the biosoptive performances of the extracted alginate was tested in the biosorption process of Cu(II) ions from aqueous solution.
Keywords: Alginate extraction; red marine algae; biosorption; Cu(II) ions; aqueous solution.

Habilitation thesis summary:
Heavy Metals Removal from Wastewaters by Sorption Processes

LAVINIA TOFAN, "Gheorghe Asachi" Technical University of Iaşi, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, lavinia_tofan@yahoo.com

pages 61 - 68 Download
Abstract
The habilitation thesis presents the most significant results of the researches oriented towards polymeric materials (organic synthetic resins and polyurethane foams) and waste materials as sorption media for heavy metal ions. Some new chelating sorbents have been prepared by covalent immobilization of desired groups, also by some special, noncovalent methods. The proposed polymer sorbents have enhanced efficiency and good selectivity towards targeted precious and toxic heavy metal ions. Some indigenous wastes (hemp, rapeseed, Romanian pine bark, fly ash) have been investigated as potential sorbents for Cu(II), Cd(II), Zn(II), Pb(II) ions. The obtained results of are significant for the future development of the tested wastes into beneficial materials for industrial and environmental applications.