1
|
Cross-Linking Combined with Surfactant Bilayer Assembly Enhances the Hydrophilic and Antifouling Properties of PTFE Microfiltration Membranes. SEPARATIONS 2021. [DOI: 10.3390/separations9010002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The inherent strong hydrophobicity of Polytetrafluoroetylene (PTFE) microfiltration membranes results in low separation efficiency and easy contamination. In order to enhance its hydrophilic and antifouling properties, we first modified the PTFE microfiltration membrane by using Polyethylene glycol laurate (PEGML) for first layer deposition and then used Polyvinyl alcohol (PVA)/citric acid (CA) cross-linked coatings for second layer deposition. The Scanning Electron Microscope (SEM) results showed that the fibers and nodes of the modified PTFE microfiltration membrane were coated with PVA/CA hydrophilic coating. FT-IR Spectromete and X-ray photoelectron spectrometer (XPS) analysis results confirmed that crosslinking of PVA and CA occurred and that PEGML and PVA/CA were successfully deposited onto the membrane surface. The modification conditions were optimized by hydrophilicity testing, and the best hydrophilicity of the modified membrane was achieved when the crosslinking content of PEGML was 2 g·L−1, PVA was 5 g·L−1, and CA was 2 g·L−1. PTFE microfiltration membranes modified by the optimal conditions achieved a water flux of 396.9 L·m−2·h−1 (three times that of the original membrane) at low operating pressures (0.05 MPa), and the contact angle decreased from 120° to 40°. Meanwhile, the modified PTFE microfiltration membrane has improved contamination resistance and good stability of the hydrophilic coating.
Collapse
|
2
|
Mohd Radzali NA, Mohd Hidzir N, Abdul Rahman I, Mokhtar AK. Mechanical properties of polymeric biomaterials: Modified ePTFE using gamma irradiation. OPEN CHEM 2021. [DOI: 10.1515/chem-2021-0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Evaluating the mechanical properties of expanded polytetrafluoroethylene (ePTFE) is essential to measure its resistance to permanent deformation from an applied force. These mechanical ePTFE properties must be comparable to the properties of real tissue. Various hydrophilic comonomers 2-hydroxyethyl methacrylate (HEMA), N-isopropylacrylamide (NIPAAM), and N-vinylcaprolactam were used individually for copolymerization with acrylic acid (AA) to be grafted onto ePTFE using the gamma irradiation-induced grafting method. After surface modification, the hydrophobic and mechanical properties of ePTFE were altered. The water uptake and contact angle measurement showed that the modified ePTFE was less hydrophobic (∼500%, θ < 90°) than the unmodified ePTFE (0%, θ = 140°). Moreover, the mechanical properties of ePTFE changed after the modification process due to the polymer grafted onto the ePTFE surface. The data from mechanical tests, such as Young’s modulus (74–121 MPa), ultimate tensile strength (5–9 MPa), and elongation at break (56–121%), obtained for the sample AA-co-HEMA and AA-co-NIPAAM remain within the ranges and are considered desirable for use as a biomaterial. The mechanical strength correlates well with the percentage of the grafting yield after the modification process and is dependent on the parameters used, such as irradiation dose and type of comonomer.
Collapse
Affiliation(s)
- Nur Ain Mohd Radzali
- Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia , 43600 Bangi , Selangor , Malaysia
- Nuclear Technology Research Centre, Faculty of Science and Technology, Universiti Kebangsaan Malaysia , 43600 Bangi , Selangor , Malaysia
| | - Norsyahidah Mohd Hidzir
- Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia , 43600 Bangi , Selangor , Malaysia
- Nuclear Technology Research Centre, Faculty of Science and Technology, Universiti Kebangsaan Malaysia , 43600 Bangi , Selangor , Malaysia
| | - Irman Abdul Rahman
- Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia , 43600 Bangi , Selangor , Malaysia
- Nuclear Technology Research Centre, Faculty of Science and Technology, Universiti Kebangsaan Malaysia , 43600 Bangi , Selangor , Malaysia
| | - Abdul Khaliq Mokhtar
- Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia , 43600 Bangi , Selangor , Malaysia
- Nuclear Technology Research Centre, Faculty of Science and Technology, Universiti Kebangsaan Malaysia , 43600 Bangi , Selangor , Malaysia
| |
Collapse
|
3
|
Mohd Hidzir N, Mohd Radzali NA, Abdul Rahman I, Shamsudin SA. Gamma irradiation-induced grafting of 2-hydroxyethyl methacrylate (HEMA) onto ePTFE for implant applications. NUCLEAR ENGINEERING AND TECHNOLOGY 2020. [DOI: 10.1016/j.net.2020.03.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
4
|
Protein adsorption to poly(tetrafluoroethylene) membranes modified with grafted poly(acrylic acid) chains. Biointerphases 2020; 15:031011. [PMID: 32527100 DOI: 10.1116/6.0000137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Protein adsorption to biomaterial surfaces is important for the function of such materials with anchorage-dependent cell adhesion requiring the presence of adsorbed proteins. The current study evaluated five solid surfaces with poly(acrylic acid) (PAA) grafted from the surface of a poly(tetrafluoroethylene) membrane with respect to the adsorption of serum albumin (SA), lactoferrin (Lf), and lysozyme (Lys) from a phosphate buffer and NaCl solution or water for specific combinations. With the use of x-ray photoelectron spectroscopy, the relative amounts and protein layer thickness were evaluated. SA adsorption was governed by ionic repulsive forces and hydrophobic interactions as evidenced from an increase in the protein adsorption at lower pH (6.5 compared to 7.4) and a correlation with surface coverage when water (pH 6.5) was used as the medium. The adsorption of Lf and Lys followed similar trends for all samples. In general, ionic attractive forces dominated and a strong correlation of increasing protein adsorption with the PAA chain length was evident. This study concluded that all surfaces appear suitable for use in biomaterial applications where tissue ingrowth is desired and that the enhanced protein adsorption in a medium with high ionic strength (e.g., biological fluid) correlates with the PAA chain length rather than the surface coverage.
Collapse
|
5
|
Feng S, Zhong Z, Wang Y, Xing W, Drioli E. Progress and perspectives in PTFE membrane: Preparation, modification, and applications. J Memb Sci 2018. [DOI: 10.1016/j.memsci.2017.12.032] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
6
|
Ranjbarzadeh-Dibazar A, Barzin J, Shokrollahi P. Microstructure crystalline domains disorder critically controls formation of nano-porous/long fibrillar morphology of ePTFE membranes. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.06.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
7
|
In vitro mineralization of dual grafted polytetrafluoroethylene membranes. Biointerphases 2017; 12:02C413. [PMID: 28565915 DOI: 10.1116/1.4984012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The modification of biomaterials by radiation induced grafting is a promising method to improve their bioactivity. Successful introduction of carboxyl and amine functional groups on the surface of a polytetrafluoroethylene membrane was achieved by grafting of acrylic acid (AA) and 2-aminoethyl methacrylate hydrochloride (AEMA) using simultaneous gamma irradiation grafting. Chemical characterization by attenuated total reflectance Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy confirmed the presence of amine and carboxylate functionalities and indicated that all protonated amines formed ion pairs with carboxyl groups, but not all carboxyl are involved in ion pairing. It was found that the irradiation doses (2, 5, or 10 kGy) affected the grafting outcome only when sulfuric acid (0.5 or 0.9 M) was added as a polymerization enhancer. The use of the inorganic acid successfully enhanced the total graft yield (GY), but the changes in the graft extent (GE) were not conclusive. Dual functional films were produced by either a one- or a two-step process. Generally, higher GY and GE values were observed for the samples produced by the two-step grafting of AA and AEMA. The in vitro mineralization in 1.5× simulated body fluid (SBF) induced the formation of carbonated hydroxyapatite as verified by FITR. All samples showed an increase in weight after mineralization with significantly larger increases observed for the samples which had the 1.5× SBF changed every third day compared to every seventh. For the dual functional samples, it was found that the sample grafted by the one-step method shows a significantly higher increase in weight despite a much lower GY compared to the sample prepared by the two-step method and this was attributed to the different architecture of grafted chains.
Collapse
|
8
|
Hidzir NM, Hill DJ, Martin D, Grøndahl L. In vitro mineralisation of grafted ePTFE membranes carrying carboxylate groups. Bioact Mater 2017; 2:27-34. [PMID: 29744408 PMCID: PMC5935022 DOI: 10.1016/j.bioactmat.2017.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 02/17/2017] [Accepted: 02/19/2017] [Indexed: 11/19/2022] Open
Abstract
In vitro mineralisation in simulated body fluid (SBF) of synthetic polymers continues to be an important area of research as the outcomes cannot be predicted. This study evaluates a series of ePTFE membranes grafted with carboxylate-containing copolymers, specifically using acrylic acid and itaconic acid for grafting. The samples differ with regards to graft density, carboxylate density and polymer topology. The type and amount of mineral produced in 1.5 × SBF was dependent on the sample characteristics as evident from XPS, SEM/EDX, and FTIR spectroscopy. It was found that the graft density affects the mineral phases that form and that low graft density appear to cause co-precipitation of calcium carbonate and calcium phosphate. Linear and branched graft copolymer topology led to hydroxyapatite mineralisation whereas crosslinked graft copolymers resulted in formation of a mixture of calcium-phosphate phases. This study demonstrates that in vitro mineralisation outcomes for carboxylate-containing graft copolymers are complex. The findings of this study have implications for the design of bioactive coatings and are important for understanding the bone-biomaterial interface.
Collapse
Affiliation(s)
- Norsyahidah Mohd Hidzir
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, 4072, Australia
| | - David J.T. Hill
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, 4072, Australia
| | - Darren Martin
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, QLD, 4072, Australia
| | - Lisbeth Grøndahl
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, 4072, Australia
| |
Collapse
|
9
|
Synthesis of narrow molecular weight distribution polyvinyl acetate by gamma–rays initiated RAFT/MADIX miniemulsion polymerization. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
10
|
Kepa K, Coleman R, Grøndahl L. In vitro mineralization of functional polymers. BIOSURFACE AND BIOTRIBOLOGY 2015. [DOI: 10.1016/j.bsbt.2015.09.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
11
|
Meléndez-Ortiz HI, Varca GHC, Lugão AB, Bucio E. Smart Polymers and Coatings Obtained by Ionizing Radiation: Synthesis and Biomedical Applications. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/ojpchem.2015.53003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|