scholarly journals Assessment of Naturally Sourced Mineral Clays for the 3D Printing of Biopolymer-Based Nanocomposite Inks

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 703
Author(s):  
Rebeca Leu Alexa ◽  
Horia Iovu ◽  
Bogdan Trica ◽  
Catalin Zaharia ◽  
Andrada Serafim ◽  
...  
Keyword(s):  
Inorganic Nanoparticles ◽  
Inorganic Filler ◽  
Barrier Effect ◽  
Inorganic Component ◽  
Physical Barrier ◽  
3D Printed ◽  
Hydrogel Swelling ◽  
Clay Layers ◽  
Nanocomposite Scaffolds ◽  
Clay Type

The present study investigated the possibility of obtaining 3D printed composite constructs using biomaterial-based nanocomposite inks. The biopolymeric matrix consisted of methacrylated gelatin (GelMA). Several types of nanoclay were added as the inorganic component. Our aim was to investigate the influence of clay type on the rheological behavior of ink formulations and to determine the morphological and structural properties of the resulting crosslinked hydrogel-based nanomaterials. Moreover, through the inclusion of nanoclays, our goal was to improve the printability and shape fidelity of nanocomposite scaffolds. The viscosity of all ink formulations was greater in the presence of inorganic nanoparticles as shear thinning occurred with increased shear rate. Hydrogel nanocomposites presented predominantly elastic rather than viscous behavior as the materials were crosslinked which led to improved mechanical properties. The inclusion of nanoclays in the biopolymeric matrix limited hydrogel swelling due the physical barrier effect but also because of the supplementary crosslinks induced by the clay layers. The distribution of inorganic filler within the GelMA-based hydrogels led to higher porosities as a consequence of their interaction with the biopolymeric ink. The present study could be useful for the development of soft nanomaterials foreseen for the additive manufacturing of customized implants for tissue engineering.

scholarly journals Evaluation of synovium-derived mesenchymal stem cells and 3D printed nanocomposite scaffolds for tissue engineering

2015 ◽  
Vol 16 (4) ◽  
pp. 045001 ◽  
Author(s):  
Jian-Feng Pan ◽  
Shuo Li ◽  
Chang-An Guo ◽  
Du-Liang Xu ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
3D Printed ◽  
Nanocomposite Scaffolds

scholarly journals Peanut Shell Derived Carbon Combined with Nano Cobalt: An Effective Flame Retardant for Epoxy Resin

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6662
Author(s):  
Jing Liang ◽  
Wenhao Yang ◽  
Anthony Chun Yin Yuen ◽  
Hu Long ◽  
Shuilai Qiu ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardants ◽  
Gravimetric Analysis ◽  
Peanut Shell ◽  
Barrier Effect ◽  
Physical Barrier ◽  
Char Layer ◽  
Peak Heat Release Rate ◽  
2D Structure

Biomass-derived carbon has been recognised as a green, economic and promising flame retardant (FR) for polymer matrix. In this paper, it is considered that the two-dimensional (2D) structure of carbonised peanut shells (PS) can lead to a physical barrier effect on polymers. The carbonised sample was prepared by the three facile methods, and firstly adopted as flame retardants for epoxy resin. The results of thermal gravimetric analysis (TGA) and cone calorimeter tests indicate that the carbon combined with nano Cobalt provides the most outstanding thermal stability in the current study. With 3 wt.% addition of the FR, both peak heat release rate (pHRR) and peak smoke production rate (PSPR) decrease by 37.9% and 33.3%, correspondingly. The flame retardancy mechanisms of the FR are further explored by XPS and TG-FTIR. The effectiveness of carbonised PS can be mainly attributed to the physical barrier effect derived by PS’s 2D structure and the catalysis effect from Cobalt, which contribute to form a dense char layer.

scholarly journals Silicon promotes the control of Meloidogyne incognita in lettuce by increasing ascorbic acid and phenolic compounds

2021 ◽  
Author(s):  
Tales Arthur de Souza Alonso ◽  
Dalila Lopes da Silva ◽  
Renato de Mello Prado ◽  
Pedro Luiz Martins Soares ◽  
Luis Felipe Lata Tenesaca ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Phenolic Compounds ◽  
Mechanisms Of Action ◽  
Plant Tissues ◽  
Barrier Effect ◽  
Physical Barrier ◽  
Chemical Action ◽  
Chemical Mechanisms ◽  
Second Stage ◽  
Chlorophyll Index

Abstract The use of silicon (Si) has a physical barrier effect on plant tissues, decreasing nematode infection in different crops. Notwithstanding, research on lettuce crop is lacking, especially regarding the chemical mechanisms of action of this beneficial element. Therefore, this study evaluates the effect of Si supply on lettuce plants infested with 0, 6000, and 12000 eggs and second stage juveniles of M. incognita, both in the absence and in the presence of Si (2 mM) in the nutrient solution. Silicon increases phenolic compounds and ascorbic acid, reducing the M. incognita population and decreasing oxidative stress. It also increases chlorophyll index and the quantum efficiency of the photosystem II (FV/FM), favoring the growth and production of lettuce plants. The use of Si decreased the number of nematodes and affected their reproduction, decreasing the number of eggs and galls in the roots of lettuce plants, being yet another sustainable alternative for the control of M. incognita. The Si benefit would be due to the combined effect of the physical barrier and the chemical action from the increase in phenolic compounds and ascorbic acid in plant tissues, improving the physiological aspects of plants.

Properties of Thermal Conductivity on Polyimide/Clay Nanocomposite Foams

2012 ◽  
Vol 229-231 ◽  
pp. 215-218
Author(s):  
Eunk Young Kim ◽  
Seung Yong Jeong ◽  
Gyo Jic Shin ◽  
Sang Kug Lee ◽  
Kyung Ho Choi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Barrier ◽  
Barrier Effect ◽  
X Ray Diffraction ◽  
Insulating Material ◽  
X Ray ◽  
Polymer Clay Nanocomposite ◽  
Nanocomposite Foams ◽  
Polyimide Matrix ◽  
Clay Layers

We synthesized polyimide (based on ODA-PMDA) and polyimide foam and polyimide/clay foam that pore size was uniform about 1㎛. We identified that the clay layers are well dispersed in polyimide matrix and achieved exfoliation structure by X-ray diffraction. And we compared thermal conductivity of PI, PI foam, PI/clay foam. Thermal conductivity decreased up to maximum 28 % by introducing both pores and clay layers. Exfoliated structure of clay leads to decrease of thermal conductivity by thermal barrier effect. Also, the presence of clay could considerably reinforce the poor mechanical properties of polyimide by foam because of interfacial interaction between clay layers and polymer matrix. Through the this results, it has shown that this study may provide an effective method to prepare polymer/clay nanocomposite foams having exfoliation structure, and can be used as insulating material having low thermal conductivity.

scholarly journals Maleimide Functionalized Siloxane Resins

1999 ◽  
Vol 576 ◽  
Author(s):  
R. M. Shaltout ◽  
D. A. Loy ◽  
D. R. Wheeler
Keyword(s):  
Diels Alder ◽  
Inorganic Filler ◽  
Side Reactions ◽  
Inorganic Component ◽  
New Class ◽  
Silicon Alkoxides ◽  
Filler Phase ◽  
Alder Adduct ◽  
Organic Monomer

ABSTRACTIn-situ filling through hydrolysis and condensation of silicon alkoxides dissolved into polymers has been utilized to generate nanocomposites in which the filler phase can be intimately associated with the polymer on relatively small length scales. One problem of the method has been achieving useful fill volumes without bulk phase separation of the growing inorganic component from the polymer. In this paper, we describe the preparation of a new class of nanocomposite materials in which the inorganic filler phase is pre-assembled before copolymerization with an organic monomer. Maleimide monomers, prepared from alkoxysilylpropyl amines and maleic anhydride, were protected against side reactions by forming the oxonorbornene Diels-Alder adduct with furan. The monomers were then reacted under solgel conditions to form oligomers or polymers making up the filler phase. The material was activated by thermal deprotection of the maleimide and reacted with organic monomers or polymers to form the filled nanocomposite.

scholarly journals Effects of Electron Beam Irradiation on 3D-Printed Biopolymers for Bone Tissue Engineering

2021 ◽  
Vol 5 (7) ◽  
pp. 182
Author(s):  
Conrad Mastalerz ◽  
Isabelle Vroman ◽  
Xavier Coqueret ◽  
Sébastien Alix
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Inorganic Filler ◽  
Great Promise ◽  
Breaking Strain ◽  
3D Printed ◽  
Dimensional Printing

Implanting scaffolds designed for the regeneration or the replacement of bone tissue damaged by diseases and injuries requires specially designed biomaterials that promote cell adhesion. However, the biodegradation rate of these scaffolds based on a single material is uniform. Four-dimensional printing appears to be a promising method to control this aspect by changing the shape and/or the intrinsic properties of 3D-printed objects under the influence of external stimuli. Two main classes of biomaterials and biocomposites based on biopolyesters, namely poly(lactic acid) (PLA) and poly(caprolactone) (PCL), were used in this study. Each of them was mixed with the inorganic filler hydroxyapatite (HA), which is a component of natural bone. The biocomposites and biomaterials were prepared using the melt extrusion process and then shaped using a 3D printer. Three-dimensional specimens showed a decrease in elongation at break and breaking strain due to variations of crystallinity. The crystallinity of irradiated samples increased slightly with irradiation and a new crystalline phase was observed in the case of the PLA. Four-dimensional printing of biomaterials using electron radiation shows great promise for bone tissue engineering based on biocomposite scaffolds and other medical applications.

scholarly journals Tissue Engineering Scaffolds Fabricated in Dissolvable 3D-Printed Molds for Patient-Specific Craniofacial Bone Regeneration

2018 ◽  
Vol 9 (3) ◽  
pp. 46 ◽  
Author(s):  
Angela de la Lastra ◽  
Katherine Hixon ◽  
Lavanya Aryan ◽  
Amanda Banks ◽  
Alexander Lin ◽  
...  
Keyword(s):  
Bone Grafting ◽  
Complex Geometry ◽  
Dry Weight ◽  
Patient Specific ◽  
Tissue Engineering Scaffolds ◽  
Defect Site ◽  
3D Printed ◽  
Hydrogel Swelling ◽  
Specific Tissue ◽  
Craniofacial Defects

The current gold standard treatment for oral clefts is autologous bone grafting. This treatment, however, presents another wound site for the patient, greater discomfort, and pediatric patients have less bone mass for bone grafting. A potential alternative treatment is the use of tissue engineered scaffolds. Hydrogels are well characterized nanoporous scaffolds and cryogels are mechanically durable, macroporous, sponge-like scaffolds. However, there has been limited research on these scaffolds for cleft craniofacial defects. 3D-printed molds can be combined with cryogel/hydrogel fabrication to create patient-specific tissue engineered scaffolds. By combining 3D-printing technology and scaffold fabrication, we were able to create scaffolds with the geometry of three cleft craniofacial defects. The scaffolds were then characterized to assess the effect of the mold on their physical properties. While the scaffolds were able to completely fill the mold, creating the desired geometry, the overall volumes were smaller than expected. The cryogels possessed porosities ranging from 79.7% to 87.2% and high interconnectivity. Additionally, the cryogels swelled from 400% to almost 1500% of their original dry weight while the hydrogel swelling did not reach 500%, demonstrating the ability to fill a defect site. Overall, despite the complex geometry, the cryogel scaffolds displayed ideal properties for bone reconstruction.

Sign in / Sign up

Export Citation Format

Share Document