Incorporating Aminated Nanodiamonds to Improve the Mechanical Properties of 3D-Printed Resin-Based Biomedical Appliances

The creation of clinically patient-specific 3D-printed biomedical appliances that can withstand the physical stresses of the complex biological environment is an important objective. To that end, this study aimed to evaluate the efficacy of aminated nanodiamonds (A-NDs) as nanofillers in biological-grade acrylate-based 3D-printed materials. Solution-based mixing was used to incorporate 0.1 wt% purified nanodiamond (NDs) and A-NDs into UV-polymerized poly(methyl methacrylate) (PMMA). The ND and A-ND nanocomposites showed significantly lower water contact angles (p < 0.001) and solubilities (p < 0.05) compared to those of the control. Both nanocomposites showed markedly improved mechanical properties, with the A-ND-containing nanocomposite showing a statistically significant increase in the flexural strength (p < 0.001), elastic modulus (p < 0.01), and impact strength (p < 0.001) compared to the control and ND-containing groups. The Vickers hardness and wear-resistance values of the A-ND-incorporated material were significantly higher (p < 0.001) than those of the control and were comparable to the values observed for the ND-containing group. In addition, trueness analysis was used to verify that 3D-printed orthodontic brackets prepared with the A-ND- and ND-nanocomposites exhibited no significant differences in accuracy. Hence, we conclude that the successful incorporation of 0.1 wt% A-ND in UV-polymerized PMMA resin significantly improves the mechanical properties of the resin for the additive manufacturing of precisive 3D-printed biomedical appliances.

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Engineering the Surface and Mechanical Properties of Water Desalination Membranes Using Ultralong Carbon Nanotubes

Membranes ◽

10.3390/membranes8040106 ◽

2018 ◽

Vol 8 (4) ◽

pp. 106 ◽

Cited By ~ 5

Author(s):

Yehia M. Manawi ◽

Kui Wang ◽

Viktor Kochkodan ◽

Daniel J. Johnson ◽

Muataz A. Atieh ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Aspect Ratio ◽

Water Flux ◽

Contact Angles ◽

Water Desalination ◽

Membrane Properties ◽

Porous Membranes ◽

Water Contact ◽

And Performance

In this work, novel polysulphone (PS) porous membranes for water desalination, incorporated with commercial and produced carbon nanotubes (CNT), were fabricated and analyzed. It was demonstrated that changing the main characteristics of CNT (e.g., loading in the dope solutions, aspect ratio, and functionality) significantly affected the membrane properties and performance including porosity, water flux, and mechanical and surface properties. The water flux of the fabricated membranes increased considerably (up to 20 times) along with the increase in CNT loading. Conversely, yield stress and Young’s modulus of the membranes dropped with the increase in the CNT loading mainly due to porosity increase. It was shown that the elongation at fracture for PS/0.25 wt. % CNT membrane was much higher than for pristine PS membrane due to enhanced compatibility of commercial CNTs with PS matrix. More pronounced effect on membrane’s mechanical properties was observed due to compatibility of CNTs with PS matrix when compared to other factors (i.e., changes in the CNT aspect ratio). The water contact angle for PS membranes incorporated with commercial CNT sharply decreased from 73° to 53° (membrane hydrophilization) for membranes with 0.1 and 1.0 wt. % of CNTs, while for the same loading of produced CNTs the water contact angles for the membrane samples increased from 66° to 72°. The obtained results show that complex interplay of various factors such as: loading of CNT in the dope solutions, aspect ratio, and functionality of CNT. These features can be used to engineer membranes with desired properties and performance.

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Facile fabrication of photoinduced superhydrophobic–superhydrophilic surfaces on cellulose substrate without strength loss

Textile Research Journal ◽

10.1177/0040517518779251 ◽

2018 ◽

Vol 89 (9) ◽

pp. 1807-1822

Author(s):

Yunjie Yin ◽

Yanyan Zhang ◽

Xiaoqian Ji ◽

Tao Zhao ◽

Chaoxia Wang

Keyword(s):

Mechanical Properties ◽

Uv Irradiation ◽

Uv Curing ◽

Contact Angles ◽

Curing Process ◽

Water Contact ◽

Cellulose Substrate ◽

Cellulose Substrates ◽

Uv Curing Process ◽

Modified Cellulose

A novel strategy was reported on the design and fabrication of functional photosensitive hybrid sols (FPHSs) by non-alcoholic emulsification in the presence of a TiO2 nanoparticle and photoinitiator via a sol-gel process using tetraethylorthosilicate, γ-methacryloxypropyltrimethoxysilane (MPS) and hydrophobic silane coupling agents as precursors. Smart cellulose substrates with alterable superhydrophobic–superhydrophilic conversion were fabricated using FPHS via the ultraviolet (UV) curing process. The liquid FPHS was photocured into solid gel during UV irradiation for 40 s with MPSs in FPHS, which was verified via Fourier transform infrared spectra. The cellulose substrates were modified with FPHSs, and the water contact angles of the modified cellulose substrates were more than 150°. The superhydrophobicity was improved by the gathering of hydrophobic chains and particle deposition of hybrid gel on the fiber surface. Nevertheless, the water contact angles of the modified cellulose substrates were receded with UV irradiation from 158° to 0° in 200 min, due to TiO2 photoinduction. The irradiated cellulose substrates were placed in the dark, and the water contact angles were recovered to about 130°, gradually. What is more, the reversible process can be repeated more than eight times. The modified cellulose substrate presented excellent washing fastness, even suffering 10 times washing processing. The mechanical properties, including breaking strength and elongation rate, were improved after the coating and UV curing process, which considerably remedied the defects of the heating curing process on the mechanical properties.

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Theoretical prediction of mechanical properties of 3D printed Kagome honeycombs and its experimental evaluation

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406219860538 ◽

2019 ◽

Vol 233 (18) ◽

pp. 6559-6576 ◽

Cited By ~ 2

Author(s):

Xuefeng Zhu ◽

Longkun Xu ◽

Xiaochen Liu ◽

Jinting Xu ◽

Ping Hu ◽

...

Keyword(s):

Mechanical Properties ◽

Shear Modulus ◽

Tensile Testing ◽

Elastic Moduli ◽

Uniaxial Tensile ◽

Anisotropy Ratio ◽

Young’S Moduli ◽

Analytical Formulas ◽

3D Printed ◽

Printed Materials

Kagome honeycomb structure is proved to incorporate excellent mechanical and actuation performances due to its special configuration. However, until now, the mechanical properties of 3D printed Kagome honeycomb have not been investigated. Hence, the objective of this work is to explore some mechanical properties of 3D-printed Kagome honeycomb structures such as elastic properties, buckling, and so on. In this paper, the analytical formulas of some mechanical properties of Kagome honeycombs made of 3D-printed materials are given. Effective elastic moduli such as Young's modulus, shear modulus, and Poisson's ratio of orthotropic Kagome honeycombs under in-plane compression and shear are derived in analytical forms. By these formulas, we investigate the relationship of the elastic moduli, the relative density, and the shape anisotropy–ratio of 3D-printed Kagome honeycomb. By the uniaxial tensile testing, the effective Young's moduli of 3D printed materials in the lateral and longitudinal directions are obtained. Then, by the analytical formulas and the experimental results, we can predict the maximum Young's moduli and the maximum shear modulus of 3D-printed Kagome honeycombs. The isotropic behavior of 3D-printed Kagome honeycombs is investigated. We also derived the equations of the initial yield strength surfaces and the buckling surfaces. We found that the sizes of the buckling surfaces of 3D printed material are smaller than that of isotropic material. The efficiency of the presented analytical formulas is verified through the tensile testing of 3D printed Kagome honeycomb specimens.

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A multi-scale analytical methodology for the prediction of mechanical properties of 3D-printed materials with continuous fibres

Additive Manufacturing ◽

10.1016/j.addma.2020.101394 ◽

2020 ◽

Vol 36 ◽

pp. 101394 ◽

Cited By ~ 1

Author(s):

E. Polyzos ◽

A. Katalagarianakis ◽

D. Polyzos ◽

D. Van Hemelrijck ◽

L. Pyl

Keyword(s):

Mechanical Properties ◽

Analytical Methodology ◽

Multi Scale ◽

3D Printed ◽

Prediction Of Mechanical Properties ◽

Printed Materials

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Superior Mechanical Behavior and Fretting Wear Resistance of 3D-Printed Inconel 625 Superalloy

Applied Sciences ◽

10.3390/app8122439 ◽

2018 ◽

Vol 8 (12) ◽

pp. 2439 ◽

Cited By ~ 8

Author(s):

Yong Gao ◽

Mingzhuo Zhou

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Wear Resistance ◽

Additive Manufacturing ◽

High Hardness ◽

Fretting Wear ◽

Inconel 625 ◽

3D Printed ◽

Inconel 625 Superalloy ◽

Electron Beam Selective Melting

Additive manufacturing (AM) nickel-based superalloys have been demonstrated to equate or exceed mechanical properties of cast and wrought counterparts but their tribological potentials have not been fully realized. This study investigates fretting wear behaviors of Inconel 625 against the 42 CrMo4 stainless steel under flat-on-flat contacts. Inconel 625 is prepared by additive manufacturing (AM) using the electron beam selective melting. Results show that it has a high hardness (335 HV), superior tensile strength (952 MPa) and yield strength (793 MPa). Tribological tests indicate that the AM-Inconel 625 can suppress wear of the surface within a depth of only ~2.4 μm at a contact load of 106 N after 2 × 104 cycles. The excellent wear resistance is attributed to the improved strength and the formation of continuous tribo-layers containing a mixture of Fe2O3, Fe3O4, Cr2O3 and Mn2O3.

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Polyjet 3D printing of tissue-mimicking materials: how well can 3D printed synthetic myocardium replicate mechanical properties of organic myocardium?

10.1101/825794 ◽

2019 ◽

Cited By ~ 3

Author(s):

Leah Severseike ◽

Vania Lee ◽

Taycia Brandon ◽

Chris Bakken ◽

Varun Bhatia

Keyword(s):

Mechanical Properties ◽

Biological Tissue ◽

Mechanical Response ◽

Axial Loading ◽

Stress Concentrations ◽

Friction Forces ◽

Compliance Testing ◽

3D Printed ◽

Printed Materials ◽

Digital Anatomy

AbstractAnatomical 3-D printing has potential for many uses in education, research and development, implant training, and procedure planning. Conventionally, the material properties of 3D printed anatomical models have often been similar only in form and not in mechanical response compared to biological tissue. The new Digital Anatomy material from Stratasys utilizes composite printed materials to more closely mimic the mechanical properties of tissue. Work was done to evaluate Digital Anatomy myocardium under axial loading for comparison with porcine myocardium regarding puncture, compliance, suturing, and cutting performance.In general, the Digital Anatomy myocardium showed promising comparisons to porcine myocardium. For compliance testing, the Digital Anatomy was either within the same range as the porcine myocardium or stiffer. Specifically, for use conditions involving higher stress concentrations or smaller displacements, Digital Anatomy was stiffer. Digital Anatomy did not perform as strongly as porcine myocardium when evaluating suture and cutting properties. The suture tore through the printed material more easily and had higher friction forces both during needle insertion and cutting. Despite these differences, the new Digital Anatomy myocardium material was much closer to the compliance of real tissue than other 3D printed materials. Furthermore, unlike biological tissue, Digital Anatomy provided repeatability of results. For tests such as cyclic compression, the material showed less than two percent variation in results between trials and between parts, resulting in lower variability than tissue. Despite some limitations, the myocardium Digital Anatomy material can be used to configure structures with similar mechanical properties to porcine myocardium in a repeatable manner, making this a valuable research tool.

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Surface Modification of Additively Manufactured Nitinol by Wet Chemical Etching

Materials ◽

10.3390/ma14247683 ◽

2021 ◽

Vol 14 (24) ◽

pp. 7683

Author(s):

Denis Nazarov ◽

Aida Rudakova ◽

Evgenii Borisov ◽

Anatoliy Popovich

Keyword(s):

Mechanical Properties ◽

Free Surface ◽

Surface Energy ◽

Surface Composition ◽

Three Dimensional ◽

Physicochemical Characteristics ◽

Contact Angles ◽

Free Surface Energy ◽

Flat Plates ◽

Water Contact

Three-dimensional printed nitinol (NiTi) alloys have broad prospects for application in medicine due to their unique mechanical properties (shape memory effect and superplasticity) and the possibilities of additive technologies. However, in addition to mechanical properties, specific physicochemical characteristics of the surface are necessary for successful medical applications. In this work, a comparative study of additively manufactured (AM) NiTi samples etched in H2SO4/H2O2, HCl/H2SO4, and NH4OH/H2O2 mixtures was performed. The morphology, topography, wettability, free surface energy, and chemical composition of the surface were studied in detail. It was found that etching in H2SO4/H2O2 practically does not change the surface morphology, while HCl/H2SO4 treatment leads to the formation of a developed morphology and topography. In addition, exposure of nitinol to H2SO4/H2O2 and HCl/H2SO4 contaminated its surface with sulfur and made the surface wettability unstable in air. Etching in NH4OH/H2O2 results in surface cracking and formation of flat plates (10–20 microns) due to the dissolution of titanium, but clearly increases the hydrophilicity of the surface (values of water contact angles are 32–58°). The etch duration (30 min or 120 min) significantly affects the morphology, topography, wettability and free surface energy for the HCl/H2SO4 and NH4OH/H2O2 etched samples, but has almost no effect on surface composition.

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