Hybrid HAp-Maleic Anhydride Copolymer Nanocomposites Obtained by In Situ Functionalisation

2005 ◽  
Vol 106 ◽  
pp. 47-56 ◽  
Author(s):  
Roxana M. Piticescu ◽  
Gabrielle Charlotte Chitanu ◽  
Mihaela Albulescu ◽  
Maria Giurginca ◽  
Madalina Laura Popescu ◽  
...  
Keyword(s):  
Maleic Anhydride ◽  
Grain Growth ◽  
Sem Analysis ◽  
Hydrothermal Conditions ◽  
Synthesis Conditions ◽  
Different Temperatures ◽  
Ft Ir ◽  
Maleic Anhydride Copolymer

The aim of the work is to establish if maleic anhydride copolymer acts as a grain growth modulator and/or as a biocompatible functionalisation agent for hydroxyapatite. Experimental work was developed in three directions: nanocomposites synthesis, nanocomposites characterization and citotoxicity tests on nanocomposites. Maleic anhydride copolymer – HAp nanocomposites were prepared by in situ functionalisation in hydrothermal conditions and were characterized by chemical quantitative analysis, XRD, FT-IR, SEM, specific surface area and picnometric densities. Chemical bonding between the copolymer carboxyl groups and calcium ions of HAp induced a peak of 1577 cm-1 on the FT-IR analysis. Following the evolution of this characteristic peak with the hydrothermal synthesis conditions (different temperatures and pressures) and corroborates the results with XRD and SEM analysis it was pointed out the copolymer grain growth modulator behaviour. Citotoxicity studies in vitro on mice fibroblast cultures were performed. The results proved the biocompatibility of new hybrid –polymer nanocomposites.

scholarly journals Synthesis of Poly(methacrylic acid-co-butyl acrylate) Grafted onto Functionalized Carbon Nanotube Nanocomposites for Drug Delivery

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 533 ◽  
Author(s):  
Josué A. Torres-Ávalos ◽  
Leonardo R. Cajero-Zul ◽  
Milton Vázquez-Lepe ◽  
Fernando A. López-Dellamary ◽  
Antonio Martínez-Richa ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Methacrylic Acid ◽  
Butyl Acrylate ◽  
Chemical Vapor ◽  
Vis Spectroscopy ◽  
Ir And Raman Spectroscopies ◽  
Ft Ir

Design of a smart drug delivery system is a topic of current interest. Under this perspective, polymer nanocomposites (PNs) of butyl acrylate (BA), methacrylic acid (MAA), and functionalized carbon nanotubes (CNTsf) were synthesized by in situ emulsion polymerization (IEP). Carbon nanotubes were synthesized by chemical vapor deposition (CVD) and purified with steam. Purified CNTs were analyzed by FE-SEM and HR-TEM. CNTsf contain acyl chloride groups attached to their surface. Purified and functionalized CNTs were studied by FT-IR and Raman spectroscopies. The synthesized nanocomposites were studied by XPS, 13C-NMR, and DSC. Anhydride groups link CNTsf to MAA–BA polymeric chains. The potentiality of the prepared nanocomposites, and of their pure polymer matrices to deliver hydrocortisone, was evaluated in vitro by UV–VIS spectroscopy. The relationship between the chemical structure of the synthesized nanocomposites, or their pure polymeric matrices, and their ability to release hydrocortisone was studied by FT-IR spectroscopy. The hydrocortisone release profile of some of the studied nanocomposites is driven by a change in the inter-associated to self-associated hydrogen bonds balance. The CNTsf used to prepare the studied nanocomposites act as hydrocortisone reservoirs.

scholarly journals Characterization of the Physical, Chemical, and Adsorption Properties of Coal-Fly-Ash–Hydroxyapatite Composites

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 774
Author(s):  
Eleonora Sočo ◽  
Dorota Papciak ◽  
Magdalena M. Michel ◽  
Dariusz Pająk ◽  
Andżelika Domoń ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Synthesis Conditions ◽  
High Calcium ◽  
Ft Ir ◽  
Ir Analysis ◽  
Wet Synthesis

(1) Hydroxyapatite (Hap), which can be obtained by several methods, is known to be a good adsorbent. Coal fly ash (CFA) is a commonly reused byproduct also used in environmental applications as an adsorbent. We sought to answer the following question: Can CFA be included in the method of Hap wet synthesis to produce a composite capable of adsorbing both heavy metals and dyes? (2) High calcium lignite CFA from the thermal power plant in Bełchatów (Poland) was used as the base to prepare CFA–Hap composites. Four types designated CFA–Hap1–4 were synthesized via the wet method of in situ precipitation. The synthesis conditions differed in terms of the calcium reactants used, pH, and temperature. We also investigated the equilibrium adsorption of Cu(II) and rhodamine B (RB) on CFA–Hap1–4. The data were fitted using the Langmuir, Freundlich, and Redlich–Peterson models and validated using R2 and χ2/DoF. Surface changes in CFA–Hap2 following Cu(II) and RB adsorption were assessed using SEM, SE, and FT-IR analysis. (3) The obtained composites contained hydroxyapatite (Ca/P 1.67) and aluminosilicates. The mode of Cu(II) and RB adsorption could be explained by the Redlich–Peterson model. The CFA–Hap2 obtained using CFA, Ca(NO3)2, and (NH4)2HPO4 at RT and pH 11 exhibited the highest maximal adsorption capacity: 73.6 mg Cu/g and 87.0 mg RB/g. (4) The clear advantage of chemisorption over physisorption was indicated by the Cu(II)–CFA–Hap system. The RB molecules present in the form of uncharged lactone were favorably adsorbed even on strongly deprotonated CFA–Hap surfaces.

Kinetic Studies on the Polymerization of Dicyclohexylmethylmethane-4,4'-Diisocyanate with Polyoxytetramethylene Diol

2013 ◽  
Vol 791-793 ◽  
pp. 32-35
Author(s):  
Jian Cheng Wang
Keyword(s):  
Rate Constant ◽  
Arrhenius Equation ◽  
Activation Enthalpy ◽  
Kinetic Studies ◽  
Activation Entropy ◽  
Dimethyl Acetamide ◽  
Different Temperatures ◽  
Ft Ir ◽  
Temperature Activation

Dicyclohexylmethylmethane-4,4'-diisocyanate is used to react with polyoxytetramethylene diol at different temperatures. N,N-Dimethyl acetamide is used as solvent.In situFT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The polymerization has been found to be a second order reaction, and the rate constant increases with the rise of temperature. Activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the polymerization are respectively calculated out, which are very useful to reveal the reaction mechanism.

scholarly journals Synthesis and Adsorption Properties of 4 –Vinylpyridine, Styrene and Maleic Anhydride Copolymer in Situ Immobilized on Silica Surface

2018 ◽  
Vol 672 (1) ◽  
pp. 104-114 ◽  
Author(s):  
E. S. Yanovska ◽  
L. O. Vretik ◽  
O. Kondratenko ◽  
O. A. Nikolaeva ◽  
D. Sternik ◽  
...  
Keyword(s):  
Maleic Anhydride ◽  
Silica Surface ◽  
Adsorption Properties ◽  
Maleic Anhydride Copolymer

In Situ FT-IR Studies on the Amine-Catalyzed Urethane Reaction Kinetics of 1,3-Butanediol

2012 ◽  
Vol 472-475 ◽  
pp. 2223-2226
Author(s):  
Peng Fei Yang
Keyword(s):  
Rate Constant ◽  
Phenyl Isocyanate ◽  
Hydroxyl Group ◽  
Activation Entropy ◽  
Ir Studies ◽  
Initial Stage ◽  
Different Temperatures ◽  
Ft Ir ◽  
Kinetics Of

Phenyl isocyanate is used to react with 1,3-butanediol at different temperatures. Toluene is used as solvent and 1,4-diazabicyclo[2,2,2]octane is used as catalyst. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of primary hydroxyl group are calculated out, which are 26.4 kJ•mol-1, 23.6 kJ•mol-1and -186.6 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.

Synthesis Alloy and Composite Materials of Nano-Silver-Nickel

2014 ◽  
Vol 989-994 ◽  
pp. 181-184
Author(s):  
Wen Jing Cui ◽  
Lin Wang ◽  
Jing Wen Fu ◽  
Dong Yu Zhao
Keyword(s):  
Solid Solution ◽  
Cyclic Voltammetry ◽  
Composite Materials ◽  
Emulsion Polymerization ◽  
Nickel Alloy ◽  
In Situ Synthesis ◽  
Synthesis Conditions ◽  
Alloy Particles ◽  
Ft Ir

In this research, Silver—nickel alloy nanocomposites has been synthesized by reducing mixture solution of Ni2+, Ag+ with hydrazine hydrate as reducer and OP-10 as surfactant. Silver—nickel alloy nanocomposites were characterized by FT-IR, XRD, SEM. And the electrochemical properties of the samples were studied by cyclic voltammetry. Ag-Ni/PANI composites were prepared by in-situ synthesis and emulsion polymerization, and the effect of conduction on the conductivity was investigated including content of alloy. The detailed analysis of the synthesis conditions shows that the reduction takes place in alkaline environment and low-temperature is propitious to generate alloy solid-solution grain. Composites prepared by emulsion polymerization in acidic aqueous solutions synthesis of polyaniline shows higher conductivity than pure polymer, due to the strong interaction between alloy particles and doping PANI.

scholarly journals Studies On Compatibilization Of Recycled Polyethylene/Thermoplastic Starch Blends By Using Different Compatibilizer

2019 ◽  
Vol 17 (1) ◽  
pp. 557-563 ◽  
Author(s):  
Barıs Oner ◽  
Tolga Gokkurt ◽  
Ayse Aytac
Keyword(s):  
Maleic Anhydride ◽  
Thermoplastic Starch ◽  
Sem Analysis ◽  
Screw Extruder ◽  
Elongation At Break ◽  
Recycled Polyethylene ◽  
Twin Screw ◽  
Starch Blends ◽  
Packaging Industry ◽  
Maleic Anhydride Copolymer

AbstractIn this study, the aim was to examine the effects of three different compatibilizers on the recycled polyethylene/ thermoplastic starch (r-LDPE/TPS) blends which are used in producing garbage bags. Polyethylene-Grafted-Maleic Anhydride (PEgMAH), maleic-anhydride modified ethylene propylene rubber (EPMgMAH) and ethylene maleic anhydride copolymer (PEMAH) were selected as the compatibilizers. r-LDPE/TPS blends with or without compatibilizer were prepared by using a twin screw extruder and characterized by means of mechanical, thermal, structural and morphological analyses. It was found that tensile strength values increased with the addition of PEgMAH but decreased with the addition of EPMgMAH. Elongations at break values of the r-LDPE/TPS blends were significantly improved by using PEgMAH and EPMgMAH. Tm and Tc values have slightly affected by the compatibilizer usage in the DSC analysis. In addition, the better interfacial interaction was observed for the compatibilized blend with the PEgMAH and EPMgMAH during the SEM analysis. It was concluded that PEgMAH and EPMgMAH showed mainly changed results in elongation at break values and this is the important parameter in the packaging industry.

scholarly journals Synthesis, structural characterization and antimicrobial evaluation of some novel piperidin-4-one oxime esters

2015 ◽  
Vol 80 (9) ◽  
pp. 1101-1111 ◽  
Author(s):  
Gokula Krishnan ◽  
R. Sivakumar ◽  
V. Thanikachalam
Keyword(s):  
Biologically Active ◽  
Good Activity ◽  
Mass Spectral ◽  
Antibacterial And Antifungal Activities ◽  
Xrd Study ◽  
Antimicrobial Evaluation ◽  
Ft Ir ◽  
Antibacterial And Antifungal

Fifteen novel biologically active piperidin-4-one oxime esters (8-22) have been synthesized with good yields. These compounds were prepared from in-situ activated carboxylic acids using POCl3 and pyridine with piperidin-4- one oximes. The structure of the title compounds were elucidated on the basis of FT-IR, NMR (1D and 2D) and mass spectral analyses. The single crystal XRD study of compounds 12 and 20 were the further evidence for the proposed structure unambiguously. All the synthesized compounds were tested for in vitro antibacterial and antifungal activities. Many of these derivatives exhibited good activity against Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Trigoderma veride and Aspergillus flavus.

scholarly journals Ανάπτυξη και χαρακτηρισμός προηγμένων νανοϋβριδικών υλικών

2016 ◽  
Author(s):  
Απόστολος Καραναστάσης
Keyword(s):  
1H Nmr ◽  
Ft Ir

Η παρούσα διατριβή πραγµατεύεται την ανάπτυξη και τον χαρακτηρισµό προηγµένων νανοϋβριδικών µικροπηκτών µε έµφαση σε τελικές βιοϊατρικές εφαρµογές ενθυλάκωσης, µεταφοράς και αποδέσµευσης ενεργών φαρµακευτικών ουσιών. Το θερµοαποκρίσιµο πολυµερές πολυ(Νισοπροπυλακρυλαµίδιο) υπήρξε το βασικό συστατικό των µικροπηκτών και το ακρυλικό οξύ χρησιµοποιήθηκε ως το δεύτερο δραστικό συµµονοµερές. Για την επιτεύξη των αριστοποιηµένων ιδιοτήτων (µέγεθος ~ 200 nm, θερµοκρασία µετάπτωσης φάσης ~ 36.7 °C, µορφολογία πυρήνα/κελύφους και επιφανειακή χηµική δραστικότητα) αναπτύχθηκε ένα πρωτόκολο πολυµερισµού κατά το οποίο το δραστικό συµµονοµερές υπεισέρχεται στην αντίδραση σε χρόνο µεταγενέστερο της έναρξης του πολυµερισµού. Για την ερµηνεία των αποτελεσµάτων προτάθηκε ένα νέο µηχανιστικό µοντέλο, σύµφωνα µε το οποίο η εισαγωγή µονοµερικών στοιχείων ακρυλικού νατρίου στις διαδιδόµενες υδροφοβικές (στην θερµοκρασία διεξαγωγής του πολυµερισµού) αλυσίδες τουPNiPAm επάγει ψευδοτασιενεργό δράση και ως εκ τούτου προκαλεί την σταθεροποίηση των αναπτυσσόµενων κολλοειδών. Ο χαρακτηρισµός των υδροδυναµικών διαστάσεων πραγµατοποιήθηκε µε δυναµική σκέδαση φωτός(DLS) µεταβλητής θερµοκρασίας σε διαφορετικές τιµές του pH. O χαρακτηρισµός του συνολικού φορτίου και των επιφανειακών δραστικών θέσεων πραγµατοποιήθηκε µέσω του συνδυασµού µετρήσεων ηλεκτροφορετικής σκέδασης φωτός (ELS) µε pH-µετρικές και ηλεκτρολυτικές τιτλοδοτήσεις. Το αριστοποιηµένο υλικό χρησιµοποιήθηκε ως ικρίωµα για την ανάπτυξη του τελικού τριλειτουγικού νανοϋβριδικού υλικού. Αρχικά συντέθηκε ένα παράγωγο της χρωµοφόρας φθορεσίνη µε φέρουσα άµινο δραστικότητα, το οποίο προσδέθηκε οµοιοπολικά στην επιφάνεια των καρβόξυλο δραστικών µικροπηκτών. Στην συνέχεια ακολούθησε η in-situ εναπόθεση της µαγνητικής νανοφάσης του γ-οξειδίου του σιδήρου στην επιφάνεια των φθορίζοντων µικροπηκτών, µέσω µίας διεργασίας καθοδηγούµενης συγκαταβύθισης αλάτων σιδήρου στις παραµένουσες δραστικές θέσεις. Ο µοριακός χαρακτηρισµός περιελάµβανε την χρήση φασµατοσκοπικών τεχνικών FT-IR, 1H-NMR και 13CNMR.Οι φωτοφυσικές ιδιότητες µελετήθηκαν µε φασµατοσκοπίες φθορισµού και ορατού-υπεριώδους (UV-Vis). Τα φθορίζοντα και φθορίζοντα/νανοϋβριδικάυλικά επέδειξαν αξιοσηµείωτη συµπεριφορά, µε διττή θερµική/οπτική αποκρισιµότητα ανάλογα µε το pH. Τα υλικά χαρακτηρίστηκαν στην στερεά κατάσταση µε θερµική σταθµική ανάλυση (TGA) και µαγνητοµετρία παλλόµενου δείγµατος (VSM) για τον προσδιορισµό του ανόργανου ποσοστού και την µελέτη των µαγνητικών ιδιοτήτων αντίστοιχα. Στο τελευταίο στάδιο της ανάπτυξης, η βιοσυµβατότητα των υλικών ως νανοφορείς αξιολογήθηκε µέσω της πρόσληψης από καρκινικά κύτταρα της σειράς HeLa και την µελέτη της κυτταρικής βιωσιµότητας µε δοκιµή ΜΤΤ. Τα υλικά αξιοποιήθηκαν περαιτέρω για την ενθυλάκωση του αντικαρκινικού φαρµάκου δοξορουβικίνη. Η µελέτη κυτταρικής πρόσληψης των νανοφορέων µε ενθυλακωµένη δοξορουβικίνη απέδειξε την ενδοκυτταρικά ελεγχόµενη απελευθέρωση του φαρµάκου από όλα τα σύστηµατα. Η παρουσία της µαγνητικής φάσης αποδεικνύεται ότι συµβάλλει καθοριστικά στην ενθυλάκωση της δοξορουβικίνης σε πολύ µεγάλο ποσοστό.Για την εξακρίβωση του µηχανισµού απελευθέρωσης, πραγµατοποιήθηκαν δοκιµές in-vitro από τις οποίες επιβεβαιώθηκε ότι η διεργασία απελευθέρωσης ελέγχεται από το pH και συγκεκριµένα πραγµατοποιείται σε ελαφρώς όξινες συνθήκες.

Injectable polyelectrolyte complex-nascent HAP biodegradable antibiotic delivery system for the treatment of osteomyelitis

2021 ◽  
Author(s):  
Liz Hannah George ◽  
Aswin Arakkal ◽  
Prathapan Sreedharan ◽  
G. S. Sailaja
Keyword(s):  
Polyelectrolyte Complex ◽  
Degradation Kinetics ◽  
Diffusion Method ◽  
Alizarin Red ◽  
E Coli ◽  
Macromolecular Network ◽  
Ft Ir ◽  
Kinetics Of

Abstract An injectable osteoconductive polyelectrolyte complex –hydroxyapatite formulation capable of controlled delivery of ciprofloxacin has been developed from a novel biodegradable polyelectrolyte complex and antibiotic loaded nascent hydroxyapatite (n-HAP) for the treatment of osteomyelitis. A single source (chitosan) derived polyelectrolytes were complexed in situ in the presence of n-HAP, pre-loaded with ciprofloxacin. The PEC- (n-HAP) nanoformulation (HPEC) was characterized by FT-IR, XRD, TGA and TEM analyses. HPEC combines functionalities of n-HAP (crystallinity and osteoconductivity) as well as PEC (biodegradable hydrophilic electrostatically bound macromolecular network) imparting better control over swelling and degradation kinetics favourable for drug release and transport of micronutrients. MTT assay and cytoskeleton staining (MG 63 cells) established cytocompatibility of HPEC. Early biomimetic mineralization of apatite was manifested under simulated physiological condition with a Ca/P of 1.23 (day 3) and 1.55 (day 6) complimented by in vitro biomineralization of MG-63 and Human Osteosarcoma (HOS) cells in a week (Alizarin Red S staining), which was further validated by calcium quantification. Antibacterial efficacy of HPEC has been evaluated by delivery kinetics of ciprofloxacin and by disc diffusion method against S. aureus and E. coli. The injectable system therefore possesses unique combination of functionalities: osteoconduction enriched with early biomineralization, antibacterial activity and is biodegradable; hence highly suitable for osteomyelitis treatment.

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