scholarly journals Production and Characterization of Porous Polymeric Membranes of PLA/PCL Blends with the Addition of Hydroxyapatite

2019 ◽  
Vol 3 (2) ◽  
pp. 45 ◽  
Author(s):  
Nayara Koba de Moura ◽  
Idália A. W. B. Siqueira ◽  
João Paulo de Barros Machado ◽  
Hueliton Wilian Kido ◽  
Ingrid Regina Avanzi ◽  
...  
Keyword(s):  
Polymer Surface ◽  
Calcium Nitrate ◽  
Polymer Membranes ◽  
Ammonium Phosphate ◽  
Polymeric Membranes ◽  
Porous Polymer ◽  
Poly Lactic Acid ◽  
Biological Studies ◽  
Phosphate Salts

Polymer membranes have been widely used in guided tissue regeneration (GTR) and guided bone regeneration (GBR). The literature recognizes that poly (lactic acid) (PLA)/poly (ε-caprolactone) (PCL) blends have better physicochemical properties and that a porous polymer surface facilitates cell adhesion and proliferation. In addition, hydroxyapatite (HAp) incorporated into the polymer matrix promotes osteoinduction properties and osteoconduction to the polymer-ceramic biocomposite. Therefore, polymer membranes of PLA/PCL blend with the addition of HAp could be an alternative to be used in GBR. HAp was obtained by precipitation using the mixture of solutions of tetrahydrate calcium nitrate and monobasic ammonium phosphate salts. The porous membranes of the PLA/PCL (80/20) blend with the addition of HAp were obtained by solvent casting with a controlled humidity method, with the dispersion of HAp in chloroform and subsequent solubilization with the components of the blend. The solution was poured into molds for solvent evaporation under a controlled humidity atmosphere. The membranes showed the formation of pores on their surface, together with dispersed HAp particles. The results showed an increase in the surface porosity and improved bioactivity properties with the addition of HAp. Moreover, in biological studies with cell culture, it was possible to observe that the membranes with HAp have no cytotoxic effect on MC3T3 cells. These results indicate a promising use of the new biomaterial for GBR.

scholarly journals Effect of Some Physical-Chemical Variables in the Synthesis of Hydroxyapatite by the Precipitation Route

2005 ◽  
Vol 284-286 ◽  
pp. 47-50 ◽  
Author(s):  
Claudia P. García ◽  
C. Paucar ◽  
J. Gaviria ◽  
Alicia Durán
Keyword(s):  
Heat Treatment ◽  
Manufacturing Process ◽  
Ageing Time ◽  
Calcium Nitrate ◽  
Ammonium Phosphate ◽  
Physical Chemical ◽  
Synthetic Hydroxyapatite ◽  
Optimal Values ◽  
Temperature Time

The synthetic hydroxyapatite is a very useful material for numerous applications in medicine as a biomaterial. One of the most economic manufacturing process is the precipitation route. In the present work, synthetic hydroxyapatite was prepared using the precipitation route, starting with aqueous solutions of calcium nitrate (Ca(NO3).4H2O ) and ammonium phosphate (H2(PO4)NH4). The effects of physical-chemical variables such as pH, temperature, time of agitation, ageing time and heat treatment of the mixture were evaluated. The characterization of the samples obtained in different conditions made possible to conclude about the optimal values of the studied variables for the synthesis of this material in laboratory conditions.

Characterization of Graft-Modified Porous Polymer Membranes

1996 ◽  
Vol 35 (2) ◽  
pp. 450-457 ◽  
Author(s):  
Joni Hautojärvi ◽  
Kyösti Kontturi ◽  
Jan H. Näsman ◽  
Bror L. Svarfvar ◽  
Pasi Viinikka ◽  
...  
Keyword(s):  
Polymer Membranes ◽  
Porous Polymer

scholarly journals Development and Characterization of a Biodegradable PLA Food Packaging Hold Monoterpene–Cyclodextrin Complexes against Alternaria alternata

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1720 ◽  
Author(s):  
Velázquez-Contreras Friné ◽  
Acevedo-Parra Hector ◽  
Nuño-Donlucas Sergio Manuel ◽  
Núñez-Delicado Estrella ◽  
Gabaldón José Antonio
Keyword(s):  
Alternaria Alternata ◽  
Food Packaging ◽  
Polymer Surface ◽  
Thermal Characterization ◽  
Intermolecular Forces ◽  
Polymer Chains ◽  
Economic Losses ◽  
Poly Lactic Acid ◽  
Injection Process

The fungi of the genus Alternaria are among the main pathogens causing post-harvest diseases and significant economic losses. The consumption of Alternaria contaminated foods may be a major risk to human health, as many Alternaria species produce several toxic mycotoxins and secondary metabolites. To protect consumer health and extend the shelf life of food products, the development of new ways of packaging is of outmost importance. The aim of this work was to investigate the antifungal capacity of a biodegradable poly(lactic acid) (PLA) package filled with thymol or carvacrol complexed in β-cyclodextrins (β-CDs) by the solubility method. Once solid complexes were obtained by spray drying, varying proportions (0.0%, 1.5%, 2.5%, and 5.0 wt%) of β-CD–thymol or β-CD–carvacrol were mixed with PLA for packaging development by injection process. The formation of stable complexes between β-CDs and carvacrol or thymol molecules was assessed by Fourier-transform infrared spectroscopy (FTIR). Mechanical, structural, and thermal characterization of the developed packaging was also carried out. The polymer surface showed a decrease in the number of cuts and folds as the amount of encapsulation increased, thereby reducing the stiffness of the packaging. In addition, thermogravimetric analysis (TGA) revealed a slight decrease in the temperature of degradation of PLA package as the concentration of the complexes increased, with β-CD–carvacrol or β-CDs–thymol complexes acting as plasticisers that lowered the intermolecular forces of the polymer chains, thereby improving the breaking point. Packages containing 2.5% and 5% β-CD–carvacrol, or 5% β-CD–thymol showed Alternaria alternata inhibition after 10 days of incubation revealing their potential uses in agrofood industry.

Synthesis and characterization of porous polymer membranes produced by interparticle crosslinking

2000 ◽  
Vol 171 (2) ◽  
pp. 285-291 ◽  
Author(s):  
Ulrich Mähr ◽  
Herry Purnama ◽  
Ellen Kempin ◽  
Reinhard Schomäcker ◽  
Karl-Heinz Reichert
Keyword(s):  
Polymer Membranes ◽  
Porous Polymer ◽  
Synthesis And Characterization

Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple

2018 ◽  
Vol 39 (4) ◽  
pp. 474-482
Author(s):  
Hoang Thi Le Thuong ◽  
Nguyen Quang Hao ◽  
Tran Thi Thuy
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Low Ph ◽  
Yeast Strains ◽  
Biological Studies ◽  
Taxonomic Characterization

Eight yeast strains (denoted as D1 to D8) were isolated from samples of natural fermented pineapple. Strain D8 showed highest alcoholic production at low pH and special aroma of pineapple has been chosen for further study. Taxonomic characterization of strain D8 using morphological, biochemical and molecular biological studies confirmed that strain D8  belong to Saccharomycetaceae family, Saccharomycetales order and Saccharomyces cerevisiae species. Therefore, we named this strain as Saccharomyces cerevisiae D8 for further study on Brandy production from pineapple. Citation: Hoang Thi Le Thuong, Nguyen Quang Hao, Tran Thi Thuy, 2017. Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple. Tap chi Sinh hoc, 39(4): 474- 482. DOI: 10.15625/0866-7160/v39n4.10864.*Corresponding author: [email protected] Received 5 December 2016, accepted 12 August 2017

scholarly journals Characterization of selective layer and biomolecules fouling in polymeric membranes for microalgae filtration applications using 3D FIB/SEM

2021 ◽  
Vol 27 (S1) ◽  
pp. 774-775
Author(s):  
Hélène Roberge ◽  
Philippe Moreau ◽  
Estelle Couallier ◽  
Patricia Abellan
Keyword(s):  
Polymeric Membranes ◽  
Selective Layer

scholarly journals Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part I: Membrane Synthesis and Characterization

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 607
Author(s):  
Carolina Hermida-Merino ◽  
Fernando Pardo ◽  
Gabriel Zarca ◽  
João M. M. Araújo ◽  
Ane Urtiaga ◽  
...  
Keyword(s):  
Polymer Membranes ◽  
Small Addition ◽  
Polymeric Membranes ◽  
Synthesis And Characterization ◽  
Complete Disappearance ◽  
Optical Profilometry ◽  
Scanning Calorimetry ◽  
Exfoliated Graphene ◽  
The Stability ◽  
Scanning Electron

In this work, polymeric membranes functionalized with ionic liquids (ILs) and exfoliated graphene nanoplatelets (xGnP) were developed and characterized. These membranes based on graphene ionanofluids (IoNFs) are promising materials for gas separation. The stability of the selected IoNFs in the polymer membranes was determined by thermogravimetric analysis (TGA). The morphology of membranes was characterized using scanning electron microscope (SEM) and interferometric optical profilometry (WLOP). SEM results evidence that upon the small addition of xGnP into the IL-dominated environment, the interaction between IL and xGnP facilitates the migration of xGnP to the surface, while suppressing the interaction between IL and Pebax®1657. Fourier transform infrared spectroscopy (FTIR) was also used to determine the polymer–IoNF interactions and the distribution of the IL in the polymer matrix. Finally, the thermodynamic properties and phase transitions (polymer–IoNF) of these functionalized membranes were studied using differential scanning calorimetry (DSC). This analysis showed a gradual decrease in the melting point of the polyamide (PA6) blocks with a decrease in the corresponding melting enthalpy and a complete disappearance of the crystallinity of the polyether (PEO) phase with increasing IL content. This evidences the high compatibility and good mixing of the polymer and the IoNF.

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