- I am professor at Gheorghe Asachi Technical University of Iasi. Romania. I am working in the natural polymers contain... moreI am professor at Gheorghe Asachi Technical University of Iasi. Romania. I am working in the natural polymers contained in biomass. I am interesting in their separation by biorefining and their biological properties. Also we study their influence in bioremediation and environmental protectionedit
The paper presents some peculiar aspects of the life and scientific activity of acad. Cr.I.S., seen through the eyes of his close collaborators.
Natural polymers are characterized by three main properties: multifunctionality, biodegradability and biocompatibility, which are essential for various applications that should comply with the environment. Due to the hugeavailability of... more
Natural polymers are characterized by three main properties: multifunctionality, biodegradability and biocompatibility, which are essential for various applications that should comply with the environment. Due to the hugeavailability of the phytomass sources resulted from photosynthesis, there are several possibilities to achieve some complex composite systems based on the utilization of natural/synthetic polymer mixtures. On the other hand, it is known that hydrophilic lignocellulosic materials and hydrophobic synthetic polymers are incompatible. The compatibility between the two kinds of polymers could be achieved by modification of either the hydrophilic natural polymer or of the synthetic one. The paper discusses the results on the modification of hardwood flour chemicals by reactions with epichlorohydrin and steroyl chloride, for the introduction of modified flour into the composite materials. The modified products were characterized by FTIR spectroscopy, thermodifferential ana...
Research Interests:
Phenolic extracts of bilberry: they protect lipid from oxidation in in vitro simulated digestion conditions. ICP 2016 - XXVIIIth International Conference on Polyphenols
Research Interests:
Research Interests: Chemistry and De Gruyter
Research Interests:
The present paper focused on the effect of unmodified and modified lignins and copper ions on the interaction between birch veneer and some biocides. The aim of the present study was to modify commercial lignins (Protobind 1000, Protobind... more
The present paper focused on the effect of unmodified and modified lignins and copper ions on the interaction between birch veneer and some biocides. The aim of the present study was to modify commercial lignins (Protobind 1000, Protobind 2000, Protobind 3000) by the hydroxymethylation reaction in an alkaline medium and to describe the lignin derivatives by chemical, spectral (H NMR) and thermal analyses (TG). The studies revealed some functional changes, which are correlated with both the different reactivity of lignins and the reaction conditions. Also, lignin derivatives were observed by thermal analysis, which allowed establishing a correlation between the modification degree and the thermal stability. Treatments with unmodified and hydroxymethylated lignins were applied to birch veneer strips by immersing them in copper chloride solutions. The lignin products were dissolved in 0.1 N ammonia solution of 5% concentration. The biostability of the treated veneer was tested by buryi...
Research Interests:
Research Interests:
A comparative study of oxidative degradation with S 2 O 8 2 - /Ag + and Fenton systems was performed on a series of ammonium lignosulphonate (ALS) solutions of different concentrations (0.079 - 3.785 mg/mL - 1 ), by means ofcyclic... more
A comparative study of oxidative degradation with S 2 O 8 2 - /Ag + and Fenton systems was performed on a series of ammonium lignosulphonate (ALS) solutions of different concentrations (0.079 - 3.785 mg/mL - 1 ), by means ofcyclic voltametry. These oxidized solutions have a complex composition and are susceptible of mutual interferences. However, cyclic voltametry can give only an overall view and estimation of such redox processes. The obtained voltammograms are quite different, as a function of the oxidants selected, and of the preliminary results (UV-VIS spectrophotometry, conductibility and turbidity data, total amount of hydroxylated aromatic compounds) obtained.
Research Interests:
In this study, the adsorption of Cu(II) ions from aqueous solutions onto wheat straw lignin was investigated. The experiments were performed in a batch system, at room temperature (20 ± 0.5 °C), and the copper ions analysis was done after... more
In this study, the adsorption of Cu(II) ions from aqueous solutions onto wheat straw lignin was investigated. The experiments were performed in a batch system, at room temperature (20 ± 0.5 °C), and the copper ions analysis was done after equilibrium was attained. Different experimental parameters (initial solution pH, sorbent dose, initial Cu(II) concentration and contact time) were varied in order to establish the optimum conditions for copper removal using wheat straw lignin. The experimental results were fitted using the Langmuir, Freundlich and Sips isotherm models, and the characteristic adsorption parameters were determined. Experimental data were also tested using two kinetic models: the pseudo-first-order Lagergren model and the pseudo-second-order Ho model. Based on these models, the kinetic parameters (rate constant and equilibrium adsorption capacity) for Cu(II) adsorption on lignin were calculated.
Research Interests:
Research Interests: Chemistry and Polyphenol
Synthese sur le potentiel et la technologie de conversion de la biomasse en produits energetiques ou chimiques
Research Interests:
Plant growth and development are influenced by various exogenous and endogenous factors. In this context, a group of substances of particular interest are polyphenols. Considering the information presented in the literature data and the... more
Plant growth and development are influenced by various exogenous and endogenous factors. In this context, a group of substances of particular interest are polyphenols. Considering the information presented in the literature data and the results obtained by our working group to date, our objective has been to study the influence of some polyphenolic extracts on the mitotic division. The investigated material comes from the seeds of maize, untreated (control) and treated with spruce bark polyphenolic extract (SBPE), hemp shives polyphenolic extract (HSPE) in different concentration. It was found that using SBPE or HSPE with lower concentration, the frequency of cells in mitosis was higher than in the control. At higher concentrations of the extracts, there were a higher number of cells with chromosomal aberrations. In the treatment variants, significant proportions had an ana-telophase (A-T) with bridges, delayed chromosomes and complex aberrations such as: A-T + bridges + late and/or...
Research Interests:
The wood suffers biodegradation processes in the environment under the biological agents’ action, influenced by environmental factors and storage or usage conditions after treatment. Depending on their structure, wood chemical... more
The wood suffers biodegradation processes in the environment under the biological agents’ action, influenced by environmental factors and storage or usage conditions after treatment. Depending on their structure, wood chemical constituents will be degraded in the following order: hemicelluloses, cellulose and lignin [1-3]. Lignin represents the resistant component to biological attack and also grants mechanical resistance to the wood. Its wide use in various fields and its relatively low stability to the action of environmental factors requires the use of chemical compounds for protection against biological agents attack. Currently, for wood protection are used toxic products for microorganisms and insects that are also environmentally incompatible. Chemical protective aqueous agents are known whose efficiency is due to the presence of copper. Part of the copper ions is fixed in the wood substratum by hydroxyl or carboxylic ionized groups in the wood at high pH. Considering lignin’s...
Polyphenols are a widespread group of secondary metabolites found in woody species, including softwood. Higher amounts of these bioactive compounds occurring in bark, heartwood, roots, branch bases and wound tissues and have a number of... more
Polyphenols are a widespread group of secondary metabolites found in woody species, including softwood. Higher amounts of these bioactive compounds occurring in bark, heartwood, roots, branch bases and wound tissues and have a number of important roles to play in viticulture and ecology, including UV protection, disease resistance, pollination, color, and defense against predation in plants, plant growth regulation and bioremediation. The use of synthetic chelates has been strongly criticized because of excessive amount of metals solubilized, associated with risk of groundwater contamination through metal leaching. This study evaluate the possibility of using natural bioactive compounds, characteristic to grape seeds extracts, in phytoextraction as an alternative to synthetic chelators. The results obtained shown an improving trend in the bioaccumulation process of heavy metals into the rape plant. It may be properly mentioned that grape seeds natural polyphenolic extract present an...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Spruce bark has been subjected to treatments with agents suitable to alkaline and acid delignification, and with organic solvents, as well as to successive extractions with petroleum ether, ethylic ether, ethylic alcohol, water and... more
Spruce bark has been subjected to treatments with agents suitable to alkaline and acid delignification, and with organic solvents, as well as to successive extractions with petroleum ether, ethylic ether, ethylic alcohol, water and alkalies. The products separated have been characterizated by elemental analysis, IR spectroscopy and get permeation chromatography, on using water or diluted alkaline solutions as elution agents. The obtained data permit to evidence some characteristics to be further employed in subsequent experiments devoted to chemical modification or utilization in various domains.
Research Interests:
Etude de l'influence des pretraitements par un alcalin et par un acide sur la biotransformation de la lignocellulose
Research Interests:
Research Interests:
The paper reviews some aspects regarding environmental protection using biodegradable composite structures based on natural and synthetic polymers. Higher plants (wood) offer the model of three-dimensional biopolymer composites, capable... more
The paper reviews some aspects regarding environmental protection using biodegradable composite structures based on natural and synthetic polymers. Higher plants (wood) offer the model of three-dimensional biopolymer composites, capable of biodegrading themselves. Starting from this, researches have been initiated for the design and realization of certain environmentally compatible products.
Research Interests:
This paper presents the results obtained by the modification of lignins through epoxydation. The reaction of lignins (commercial products Protobind 1000, Protobind 2000, Protobind 3000) with epichlorohydrin was performed in basic... more
This paper presents the results obtained by the modification of lignins through epoxydation. The reaction of lignins (commercial products Protobind 1000, Protobind 2000, Protobind 3000) with epichlorohydrin was performed in basic catalysis aiming to increase their functionality. The resulting products were characterized in terms of functionality (content of epoxy groups) and by FTIR, fluorescence and H NMR spectroscopy. The chemical and spectral characterization showed that the Pb3000 lignin was the most reactive substrate in terms of functionality. The efficiency of unmodified and epoxidated lignin derivatives was tested in biocide systems in order to ensure the protection of lignocellulosic materials. It has been noticed that the chemical modification of lignin assures a higher capacity of biostabilisation for the protection of cellulose fibers, compared to the unmodified product.
Research Interests:
The aim of this study is to evaluate the possibility of using hemp shives as natural amendments in a phytoremediation sequence. Thus, plant growth tests were conducted for rapeseed (Brassica napus) and flax (Linum usitatissimum) in... more
The aim of this study is to evaluate the possibility of using hemp shives as natural amendments in a phytoremediation sequence. Thus, plant growth tests were conducted for rapeseed (Brassica napus) and flax (Linum usitatissimum) in vegetation pots with sandy soil. These were seeded in a cadmium artificial contaminated environment with or without hemp shives. The efficiency of hemp shives as natural amendments was evaluated after 40 days of initiating experimental model, by evaluation of plant growth and development of plants through biometric and gravimetric measurements. Also, the concentration of assimilatory pigments was determined. In order to establish bioaccumulation capacity, degree of recovery and translocation factor, it was determined the concentration of cadmium metal ions absorbed in various parts of rapeseed and flax plants. It has been found that the development of the root system is more pronounced in the presence of hemp shives both in contamination with cadmium ions...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Over the past few years, special attention has been paid to biomass valorization. The aim of this paper is to evaluate the effect of the phenolic rich extracts obtained from raw materials on the growth and development of lemon balm... more
Over the past few years, special attention has been paid to biomass valorization. The aim of this paper is to evaluate the effect of the phenolic rich extracts obtained from raw materials on the growth and development of lemon balm (Melissa officinalis L.). The extracts were obtained from the bark of spruce (Picea abies (L.) H. Karst) and beech (Fagus sylvatica L.) separated as waste product during wood processing. The growth and development of the plants was assessed by measuring elongation of vegetative organs, biomasses including root, stem, and leaf, and photosynthetic pigment content. In addition, the analysis of some histo-anatomic characteristics of the vegetative organs were made. Elongation biomasses and photosynthetic pigments concentration presented higher values in case of plants treated with beech bark phenolic extract compared to control plants. The spruce bark phenolic extract had a stimulatory effect on the germination but inhibited the growth and development of the ...
Research Interests:
Research Interests:
Research Interests:
Severian Dumitriu (founder editor) and Valentin Popa (editor), Polymeric Biomaterials (2vols), Structure and function (vol I); Medicinal and Pharmacutical Applications (vol II), CRC Press/Taylor& amp;Francis Publication Date: January 16, 2013 | ISBN-10:1420094726 | ISBN-13:978-1420094725 | Editio...more
Research Interests:
In the present paper the mechanism and kinetics of methane-water mixtures decomposition in cold plasma are discussed. It was found that nature and composition of the products depend on reaction time, ratio of the two components, and how... more
In the present paper the mechanism and kinetics of methane-water mixtures decomposition in cold plasma are discussed. It was found that nature and composition of the products depend on reaction time, ratio of the two components, and how long the products are in contact after the decomposition was performed. Reactions in the decomposition system generally follow two mechanisms: corresponding to the discharge phase and to postreaction one. The highest yield of formaldehyde was obtained for the ratio methane water of 0.6-1 and two minutes of discharge.
Research Interests:
Two industrial by-products, deuterium depleted water (DDW) and polyphenolic extract from spruce wood bark (SB) were tested as bioregulators for maize callus cultures. The effects of deuterium depleted water alone or in combination with... more
Two industrial by-products, deuterium depleted water (DDW) and polyphenolic extract from spruce wood bark (SB) were tested as bioregulators for maize callus cultures. The effects of deuterium depleted water alone or in combination with spruce bark extract on growth and development in vitro of callus maize plant were studied. Specific parameters including biomass accumulation, adventitious roots and aerial adventitious roots organogenesis, formation of new callus, as well as activity of enzymes such as peroxidase, superoxide dismutase, catalase and total content of polyphenolic compounds accumulated in callus have been closely monitored. The results have shown that the tested solutions have stimulated the fresh biomass acumulation, adventitious roots organogenesis and formation of new callus by comparison with the control sample. The most significant stimulatory effect on callus biomass accumulation and total content of polyphenolic compounds was observed when the deuterium depleted ...
Research Interests:
Research Interests:
At present the universities play an important role in the knowledge society by their significant contributions not only in the people education, but also in the countries with social and economical progresses. The functions of the... more
At present the universities play an important role in the knowledge society by their significant contributions not only in the people education, but also in the countries with social and economical progresses. The functions of the universities can be accomplished taking into account the well-known humboldtian concept of synergism between education and research activities which is discussed in this paper. The excellence has to characterize the university and this can be achieved only if the government includes education and research fields in its strategy.