Ionel Marcel Popa

Gheorghe Asachi Technical University of Iasi | TU Iasi · Faculty of Chemical Engineering and Environmental Protection

Fine-tuning of the scaffolds structural features for bone tissue engineering can be an efficient approach to regulate the specific response of the osteoblasts. Here, we loaded magnetic nanoparticles aka superparamagnetic iron oxide nanoparticles (SPIONs) into 3D composite scaffolds based on biological macromolecules (chitosan, collagen, hyaluronic...

Background and objectives: Cancer is the second leading cause of death globally, an alarming but expected increase. In comparison to other types of cancer, malignant bone tumors are unusual and their treatment is a real challenge. This paper’s main purpose is the study of the potential application of composite scaffolds based on biopolymers and cal...

Composites based on combination of biopolymers (chitosan, hyaluronic acid and bovine serum albumin or gelatin), calcium phosphates (CP) and magnetic nanoparticles have been prepared by a biomimetic co-precipitation method. The biomimetic strategy is inspired by natural mineralization processes, where the synthesized minerals are usually combined wi...

Natural proteins have been extensively studied as matrices for tissue engineering, due to their excellent biocompatibility and biological properties associated with increasing cell proliferation. By generating complex materials, cell and tissue functions can be tailored to obtain a specific direction, according to the medical needs. The aim of this...

Considering its functions (support, protection, assisting in movement and storage of minerals), the bone is an essential organ for the human body and the bone trauma/damages have a great impact on the human body functionality. For that reason a variety of biomaterials are studied for potential applications in bone regeneration or substitution. Bone...

The elaboration of chemically crosslinked hydrogels based on collagen (C), hyaluronanic acid (HA) and sericin (S) with different polymer ratios was investigated by in-situ rheology. This reaction was performed via amide or ester bond reaction activated by carbodiimide, in pure water. Prior to molecule crosslinking, the rheological behaviour of the...

Carboxymethyl guar gum (CMGG) synthesized from commercially available polysaccharide was formulated into nanoparticles via ionic gelation using trisodium trimetaphosphate (STMP) as cross-linking agent. Characterisation using a range of analytical techniques (FTIR, NMR, GPC, TGA and DLS) confirmed the CMGG structure and revealed the effect of the CM...

The aim of this study is to evaluate novel hybrid materials as potential candidates for producing coatings with hierarchical roughness and controlled wetting behaviour. Magnetite (Fe3O4) nanoparticles obtained by co-precipitation were embedded in matrices synthesized by radical graft co-polymerization of butyl acrylate (BA), butyl methacrylate (BMA...

Evaluate and compare the wetting behavior of hybrid composite coatings prepared with two different UV initiators for water-repellent applications.

An original Ni-AlSiO2 mesoporous catalyst (Si/Al = 6.5, 2.0 wt% Ni) was prepared using a commercial mesoporous non-ordered silica as a support. It exhibited notable catalytic behaviour for the oligomerization of ethylene in both batch and flow mode. Thus, at 150 °C and 3.5 MPa, the catalyst was highly active (up to 130 g of oligomers per gram of th...

In this paper we report the preparation and characterization of new hybrid composites based on ZnAl-nitrate layered double hydroxides (ZnAlLDHs) and tramadol hydrochloride (TrH) via anionic exchange method. LDHs and their hybrid composites were studied by X-ray diffraction (XRD), FT-IR, RAMAN and energy dispersive x-ray (EDX) spectroscopy and scann...

An efficient process for preparing a series of magnetic chitosan grafted (alkyl acrylate) composite particles as novel adsorbent materials has been proposed. Magnetite nanoparticles (Fe3O4) were produced by co-precipitation. Modified chitosan (CSg) bearing surface vinyl groups was synthesized by glycidyl methacrylate coupling in acidic aqueous solu...

Magnetic scaffolds have been obtained using a process of precipitation of calcium phosphates from precursors (CaCl2 and NaH2PO4) on a mixture of biopolymers (chitosan, collagen, sodium hyaluronate) and SPIONs (magnetite coated with chitosan). Three-dimensional porous structures of the magnetic scaffolds has been revealed by Scanning Electron Micros...

In rural areas of Romania and other developing countries wounds and dermal affections represent one of the five most common reasons for people seeking medical care. The use of traditional medicines to treat many of these conditions has received little research or policy attention. The present work addresses the discovery of non-toxic treatments for...

The aim of this experiment is to study the therapeutic effect on cutaneous incision wounds of a new ointment based on lyophilized albumin extracted from egg. The therapeutical assessments of the proposed ointment were carried out in vivo on the skin linear incisions induced on Wistar rat. The wounds were treated topically once a day, during 21 days...

Iron oxide nanoparticles able to magnetically assemble during the curing stage of a polymeric support to create micro-scale surface protuberances in a controlled manner were prepared and characterized. The bare Fe3O4 particles were obtained by two methods: co-precipitation from an aqueous solution containing Fe3+/Fe2+ ions with a molar ratio of 2:1...

The thermal decomposition of hydrogels based on N-maleoyl chitosan and poly(acrylic acid-co-ethyl acrylate) (NMACs-P(AA-co-EA)) and its precursors (chitosan and N-maleoyl chitosan) was studied by thermogravimetric analysis coupled to Fourier transform infrared spectroscopy and mass spectrometry (TGA/FTIR/MS). These coupled techniques allow collecti...

Ni-exchanged mesoporous materials with SBA-15 topology were prepared by post-synthesis alumination of SBA-15 silica with sodium aluminate at room temperature, followed by ion exchange with nickel. Exploration of various parameters resulted in a simple preparation method for catalysts with perfect pore system and aluminium tetrahedrally coordinated...

Ni-AlSBA-15 oligomerization catalysts (2.6 wt% Ni, Si/Al = 7) were prepared by post-synthesis alumination of SBA-15 silica with sodium aluminate, followed by ion exchange with nickel. Characterization techniques, including powder X-ray diffraction, N2 sorption, TEM, 27Al, and 29Si MAS NMR proved the perfect pore system of the SBA-15 materials, with...

An original method for converting ethylene to propylene involving cascade oligomerization/isomerization/metathesis reactions over two robust and highly active heterogeneous catalysts is investigated. In a single flow reactor and under identical conditions, ethylene was first selectively dimerized/isomerized over Ni-AlSBA-15 catalyst to form 2-buten...

New hydrogels based on hyaluronic acid derivative were obtained by acrylic acid (AA) copolymerization with maleoyl-hyaluronic acid (HAD), in the presence of a redox initiation system. Simultaneously with the crosslinked co-polymerization, the homopolymerization of the acrylic acid takes place due to its highly reactivity and semi-interpenetrated ne...

Reactive Blue 19 (RB 19) dye removal from aqueous solutions by using layered double hydroxides containing nitrate as the intergallery anion (MgAlLDH) as adsorbents was investigated. The adsorption process was found to be influenced by the contact time, the initial dye concentration, the presence of inorganic anions and the temperature. The XRD and...

Aims: Carrier polymeric materials based on chitosan and chitosan / montmorillonite crosslinked with glutaraldehyde were prepared and studied for their biocompatibility, nontoxicity, and biodegradability aiming their application in drug delivery. Study Design: Polymeric materials based on chitosan and chitosan/ montmorillonite crosslinked with gluta...

This experiment studies the therapeutic effect of a new ointment based on lyophilized albumin extracted from egg on cutaneous excision lesion. The therapeutical assessments of the proposed ointment were done in vivo on the excisions excided on Wistar rat. The wounds were treated topically once a day, along 21 days. Clinical and macroscopic tests, t...

Flaxseed lignans are a natural source of useful biologically active components that show a diverse spectrum of health-promoting properties. The valuable effects of the phenolic molecules are mainly due to their antioxidant activity by preventing oxidative stress and stimulate collagen synthesis, therefore, providing benefits to the skin. The presen...

We prepared solid spheres, with diameters between 100 and 400 nm, encapsulating silver nanocrystallites (about 20 +/- 10 nm in diameter), by heating colloidal solutions of silver in methoxyethanol at 120 degrees C. Stable coatings were obtained using spin coating and rapid thermal processing on optical glass substrates. UV-Vis spectroscopy measurem...

The ampicillin coupling on BIOZAN R (a polysaccharide of microbial synthesis Xanthomonas campestris) is studied by the activation of carboxylic groups by dicyclohexylcarbodiimide. The following optimum reaction parameters are settled on the basis of an experimental program: time = 7.5 h, temperature = 10 °C, dicyclohexylcarbodiimide concentration =...

Flaxseed cake, a by-product of the oil cold pressing technology, was subjected to extraction and acidic hydrolysis to obtain extracts rich in polyphenols and especially in lignans. The second step was to assess the extracts in order to evaluate their potential to be used as additives in the food and cosmetics industries. The identification and quan...

Poly(acrylic acid) (PAA) and poly(ethylene glycol) (PEG), four-arm, amine-terminated particles with nanometer size and spherical shape were obtained by the polymers cross-linking, via activation with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride, in a w/o emulsion. The morphology and surface charge of the final particles are strongl...

This paper presents the synthesis and characterization of gellan gum derivatives containing quaternary ammonium groups, with the purpose of obtaining particulate controlled release systems for ciprofloxacin. Quaternized gellan derivatives were synthesized by grafting N-(3-chloro-2-hydroxypropyl)-trimethyl ammonium chloride onto gellan primary hydro...

The intercalation of 2,6-dichlorobenzonitrile (DBN) into the NiMgAlLDH, CuMgAlLDH and MgAlLDH layered double hydroxides was carried out using the calcination-rehydration reaction using NiMgAl, CuMgAl and MgAl oxide precursors, obtained by calcination at 550 degrees C. X-ray diffraction (XRD), elemental analysis, infrared spectroscopy (FTIR) and the...

Hydrogels with semi-interpenetrating (semi-IPN) structure were synthesized by radical copolymerization of maleoyl-chitosan (N-MA-Cs) and acrylic acid (AA) in the presence of ammonium persulfate (APS) and N,N,N′,N′-tetramethylethylenediamine (TEMED) as initiating system. Network structure and morphology were confirmed by Fourier Transform Infrared S...

The present paper deals with the microscopic and colorimetric characterization of 18 thermally and photo-resistant pigments, obtained by co-precipitation in an aqueous system, based on phosphate and zinc chromate chromophore structures, chemically doped with Mn(II), Fe(II), Fe(III), Co(II), Ni(II) and Bi(III) cations. The optical microscopic analys...

This paper presents a comparative study regarding the impact behavior between two biocomposites with different matrices, polypropylene and furan resins, reinforced with the same volume fractions of hemp shives. Also the paper analyzes the influence of the volume fraction of the hemp shives on the impact properties of polypropylene-based biocomposit...

Oxide ion conductors have been increasingly studied for many years because of their application in devices with high economical impact such as solid oxide fuel cells (SOFC), oxygen sensors, and dense ceramic membranes for oxygen separation, and membrane reactors for oxidative catalysis. New fast oxide ion conductors for low temperature applications...

The article studies thermal resistance variation by analyzing the colorimetric parameters correlated with the optical microscopy data of two groups of ceramic pigments obtained by co-precipitation in aqueous medium of phosphate anion and of a mixture of chromium phosphate with various chromophore cations. This research enabled us to reveal the ther...

This work reports on the physicochemical properties and in vitro cytotoxicity assessment of chitosan-calcium phosphate (Cs-CP) scaffolds for bone tissue engineering, which were synthesized by a novel biomimetic co-precipitation method. X-ray diffraction (XRD) along with scanning electron microscopy (SEM) analysis confirmed the porous morphology of...

This paper aimed at developing a procedure for the entrapment of flaxseed extract into xanthan-chitosan polyionic complex and studying the kinetic aspects of its in vitro release. The total phenolic content, radical scavenging activity and the concentration of delivered secoisolariciresinol (SECO) were determined. The release of SECO from the Xa-CS...

The xanthan/chondroitin sulfate (X/CS) hydrogels, obtained by a crosslinking technique, were evaluated in vitro and in vivo as matrices for theophylline release. The influence of pH of simulated physiological media on the X/CS swelling behaviour at 37 0C was investigated. The hydrogels loading degree with theophylline was evaluated by near infrared...

This paper presents the obtaining and the characterization of composites with polypropylene matrix and hemp shives as filler in different ratios and containing poly(propylene)-co maleic anhydride (MAH-PP) 3% wt as compatibility agent. The weathering behavior of the composite enclosing 60% hemp shives, performed after the exposure to UV radiations a...

The production of a wide variety of biocompatible thin films by laser ablation deposed on the biomaterial substrates does not induce inflammatory response and repulsion by the immunization human body. Anodic potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were used for the study of the electrochemical behavi...

In vitro and in vivo release of the theophylline, loaded in mixed polysaccharidic cellulose/chondroitin sulfate (C/CS) hydrogels has been evaluated. The C/CS hydrogels in various mixing ratios obtained by a crosslinking technique were supplementary characterized by swelling studies in a pH 2.2 acidic solution at 37 °C, simulating the gastrointestin...

a b s t r a c t A method for preparing magnetic composite particles with a core containing iron oxide encapsulated in crosslinked chitosan (CS) and a functionalized synthetic copolymer shell is proposed and optimized. The magnetic material is produced in situ. Surface vinyl groups are introduced by attaching glycidyl methac-rylate (GMA) to the hydr...

New hybrid materials were obtained by intercalation of the antioxidant compounds vanillic acid and gallic acid in layered double hydroxides (LDHs) resulting formulations with controlled release and antioxidant activity. The hybrid materials were prepared by using two methods: coprecipitation and ion exchange. X-ray powder diffraction, infrared spec...

Functionalized magnetic composites based on block copolymers poly(succinimide)-b-poly(ethylene glycol) have been obtained by immobilization of biotin on composites particles via activation with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDAC). Dynamic light scattering measurements showed that hydrodynamic mean diameters of the f...

Molecular dynamics simulations have been carried out to investigate the collective transport properties of shear viscosity coefficients in the penetrable-sphere model fluid. A qualitative agreement is found between simulation results and an empirical Enskog-like approximation proposed in this present work. However, the mismatching tendencies are gr...

A novel biomimetic technique for obtaining chitosan-calcium phosphates (Cs-CP) scaffolds are presented: calcium phosphates are precipitated from its precursors, CaCl(2) and NaH(2) PO(4) on the Cs matrix, under physiological conditions (human body temperature and body fluid pH; 37°C and pH = 7.2, respectively). Materials composition and structure ha...

Five alternating copolymers of maleic acid with N-vinylpyrrolidone, vinyl acetate, styrene, 2-vinylnaphthalene, and vinyl cyclohexane were used in order to study the influence of the comonomer on the polyelectrolyte behavior. The dissociation of the maleic acid copolymers was investigated by electrochemical methods in pure water and in the presence...

The paper presents the thermal characterisation of 18 photostable pigments obtained by co-precipitation in aqueous systems, based on precursors with chromophore structures of zinc phosphate and chromate, chemically doped with Mn(II), Fe(II), Fe(III), Co(II), Ni(II) and Bi(III) cations. The thermal analysis of the precursors highlighted the thermal...

The paper presents the thermal characterisation of 18 photostable pigments obtained by co-precipitation in aqueous systems, based on precursors with chromophore structures of zinc phosphate and chromáte, chemically doped with Mn(II), Fe(Il), Fe(IIl), Co(Il), Ni(II) and Bi(III) cations. The thermal analysis of the precursors highlighted the thermal...

Cited References Count:43|SPRINGER|VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS|ISI Document Delivery No.:895RY

Poly(hydroxyethyl methacrylate) (p(HEMA)) hydrogels have been proposed as promising biomaterials to replace damaged articular cartilage. A major obstacle to their use as replacement bearing tissue is their poor mechanical properties in comparison with healthy articular cartilage. The purpose of this study was to obtain p(HEMA) hydrogels with physic...

Magnetic chitosan composite particles with 40μm average size and 24emu/g saturation magnetization obtained by an in situ procedure were evaluated as a new low-cost adsorbent for radioactive wastewater decontamination. Sorbent characterization by SEM, EDX, FTIR and magnetization measurements proved that the target ions were bound and their surface d...

The present experiment evaluates the efficacy of the topical treatment with propolis, honey and Royal Jelly of chemically induced erythema in Wistar rats. Clinical and histopathological results reveal the benefic effect of the above mentioned bee products upon erythema, with complete healing of the lesion after seven days of treatment, and with evi...

The present paper presents the synthesis and chemical characterization of 18 thermally and photo-resistant ceramic pigments, obtained by aqueous system coprecipitation, based on a zinc phosphate and chromate/dichromate chromophore structure (considered as basic precursor), chemically doped with Mn(II), Fe(II), Fe(III), Co(II), Ni(II) and Bi(III) ca...

The alternating maleic acid–2-vinylnaphthalene copolymer was synthetized and characterized. The amphiphilic polyelectrolyte adopts a pseudomicellar conformation in aqueous solution. The hydrophobic microdomains are formed by the naphthalene groups and the water solubility is conferred by the hydrophilic maleic acid groups. The two-step dissociation...

A method for preparing magnetic crosslinked chitosan microparticles was developed. The chitosan (CS) encapsulated magnetic particles were produced in alkaline conditions by in situ oxidation of the ferrous ions initially dispersed uniformly within the polysaccharide matrix. The polymer was then crosslinked using glutaraldehyde (GLA). The products w...

This paper reports a novel biomimetic technique for obtaining chitosan–calcium phosphate composite scaffolds (Cs–CP) by calcium phosphate precipitation from its precursors,CaCl2 and NaH2PO4 in the presence of ammonia and Cs, followed by product freeze-drying. The structural and morphological analysis showed the arrangement of CP onto Cs fibers, whi...

Chitosan (CS), the unique cationic groups-containing polysaccharide, is a natural, renewable, nontoxic and biodegradable material, considered as an ecologically-friendly product. Several studies on the obtaining of intermolecular complexes (IMC) between CS and natural or synthetic anionic polyelectrolytes have been reported. CS and dextran sulphate...

Recent studies focus on the chemical modification of polysaccharides for biomedical applications. Guar gum is a natural polymer composed of linear chains of (l-4)-ß-D mannopyranosyl units with α-Dgalactopyranosyl units attached by (1-6) linkages, in a ratio of about 1.5-2, possessing hydroxyl groups available for the attachment of biologically acti...

This work addresses the obtaining of biocompatible magnetic polyvinyl alcohol—chitosan microspheres, specifically tailored/functionalised to bind directly blood toxins using an emulsion crosslinking preparation method. The following synthesis parameters were studied: water to oil phase ratio, polyvinyl alcohol molecular weight, chitosan to polyviny...

Biofunctionalized magnetic composites have been obtained by immobilization of biotin via activation with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDAC) on chitosan-magnetite based particles. FT-IR and TEM analyses confirmed that biotinylated particles have been successfully prepared. Dynamic light scattering measurements showe...

In the present work we describe a novel route for preparation of biomimetic bone scaffolds based on biopolymers as chitosan (Cs), hyaluronic acid (Hya), chondroitin sulfate (ChS) and calcium phosphate (CP). The biopolymers-CP composite scaffolds were analyzed by Fourier transformed infrared spectroscopy, scanning electron microscopy, X-ray diffract...

The purpose of this experiment was to evaluate the influence of apitherapy diet in Wistar rats with experimentally carbon tetrachloride (CCl 4) induced hepatopathy by determining the evolution of hematological parameters (number of erythrocytes - RBC; hemoglobin - HGB; hematocrit - HCT; mean corpuscular volume - MCV, VEM; mean corpuscular hemoglobi...

The present experiment aims to evaluate the influence of apitherapy diet on CCl 4 induced liver disease in Wistar rats by achieving the values of direct and indirect bilirubin. In order to reduce the factors that accelerate the progression of liver damage apitherapy products (Apiregya, ApiImunomod, ApiImunostim, ApiImunostim Forte) have been admini...

Palladium nanoparticles supported within hybrid organic–inorganic foams have been generated. The as-synthesized catalysts, labeled “Pd@gOrgano-Si(HIPE)” (high internal phase emulsion), have been tested with or without addition of triphenylphosphine (PPh3), considering both the Suzuki–Miyaura and Mizoroki–Heck coupling reactions. Particularly, the c...

Current surgical implants such as artificial hip and knee joints undergo degradation after 10-15 years of use. Despite the success of surgical implants materials used in these procedures still do not satisfy the demands of a durable functioning joint. The most common causes of implant failure have been and still are stem loosening and wear between...

Ketoprofen (Ket) was intercalated into layered double hydroxides (ZnAlLDH and MgAlLDH) using the ionic exchange method. The drug intercalation was confirmed by X-ray diffraction (XRD) and FTIR spectroscopy. Ket release from the inorganic matrix was studied at pH 7.4 in continuous regime with a flow rate of 0.5 and respectively 1.0 ml/min. The kinet...

Organo-mineral nanohibrid materials in which the organic moiety is intercalated inside the inorganic lamella were prepared by an ion exchange method. Ketoprofen (KET) anions were used as guest molecules, while ZnAl and MgAl layered double hydroxides (ZnAlLDH and MgAlLDH) were used as inorganic hosts. The intercalated compounds were examined by X-ra...

Novocaine was immobilized on BIOZANR after activation with dicyclohexylcarbodiimide. Under the optimum coupling conditions described (temperature, reagent concentration) a reaction product with novocaine content of 37% was obtained. Penicillin G was then bound to the BIOZAN-novocaine complex resulting in an antibiotic with prolonged action and high...

The objective of this study is to compare the tribological characteristic at macro- and nano-scale between the hydrogels based on hydroxylethyl methacrylate (HEMA) in articular cartilage. This study shows that the mechanical and tribological properties are similar at the nano- and macro-scale, irrespective of whether the surface roughness is small...

In this study, new hybrid Organo-Si(HIPE) macrocellular foams have been synthesized via sol–gel process, direct emulsions and lyotropic mesophases as templating agents followed by a final grafting process of silane organically modified. A variety of sililated groups, including methyl, benzyl, amines, mercapto, pyrrol and dinitro have been successfu...

Chitosan (CS) based microparticles for controlled release of theophylline (THP) were obtained by ionic gelation. The microparticles were characterized by laser diffraction analysis (particle size), scanning electron microscopy (SEM), FTIR spectroscopy, and thermogravimetric analysis. The average diameter of the CS-THP microparticles was 182 μ m. Th...

Nanostructured membranes and films of cationic surfactant-chitosan with tannic acid as polyphenol model were obtained by phase inversion method. The membranes were investigated by Attenuated Total Reflectance Fourier Transform InfraRred, X-Ray Diffraction, Scanning Electron Microscopy and Thermogravimetry, and the films topography was analysed by A...

A method for the preparation of magnetite/chitosan composite nanoparticles was developed. Colloidal magnetite particles (Fe 3 O 4) produced by co-precipitation and stabilized in suspension by adding a non-ionic surfactant (Pluronic F127) were subsequently covered with a layer of chitosan (CS) prepared by ionotropic gelation using sodium tripolyphos...

The amphiphilic polymers can form associated structures in aqueous solution by mutual interaction and/or interaction with other components such as surfactants and active colloidal molecules. In this paper, results regarding nanolevel associative behaviour of chitosan based systems with surfactant and paracetamol are presented. The viscosity measure...

The aim of this paper is theophylline (THP) inclusion into xanthan–chitosan polyionic complex (Xa–CS) and the study of its in vitro and in vivo kinetic release. Xa–CS hydrogel was obtained by ionic complexation between two oppositely charged polysaccharides. THP was loaded into the Xa–CS matrix by diffusion of the drug solution. The obtained sample...

Chitosan-Hydroxyapatite (Cs-Hap) composites were prepared through a biomimetic method by Hap precipitation from its precursors, CaCl2 and NaH2PO4, on the chitosan fibres. Materials composition and structure have been analyzed by usual analytical techniques, Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). FT-I...

Two types of microparticles based on alginate and chitosan with encapsulated ciprofloxacine (CF) were prepared directly, by ionic exchange. The particles were characterized by FTIR spectroscopy and analyzed by termogravimetric techniques. The FTIR specters indicated the presence of the polymer-drug complex obtained via electrostatic interactions be...

The paper presents the obtaining and properties of films based on collagen and chitosan; the influence of the molecular weight of the chitosan on the polymers compatibility was analysed. Films were characterised by FTIR, thermo gravimetric analysis, AFM. In the aim to use the collagen-chitosan films as materials for wound dressing, in vitro degrada...

In this work, we present the experimental values of excess molar enthalpies, [image omitted], and excess molar volumes, [image omitted], for a set of mixtures composed of ethylbenzene with several alkanes, from heptane to hexadecane, and the first four alkyl ethanoates. In all cases, measurements were made at the two temperatures of 298.15 and of 3...

Co nanocrystallites were encapsulated in boron nitride closed shells using a one-step simple chemical method, the decomposition of amine complex in the presence of KBH4 and nitrogen atmosphere at 1000 °C. Magnetic measurements determined a value of the saturation magnetization of 72 emu/g and a weak ferromagnetic behavior, with a coercivity of 82 O...

The preparation of microspheres containing chitosan, sodium alginate and ibuprofen and the pH dependent drug release were investigated. The microspheres were prepared by two experimental routes: the first one starting with a chitosan/ibuprofen core subsequently coated by an alginate shell (S1) and the second one based on an alginate/ibuprofen core,...