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Minsu Kim, Sang Wook Kang
Poly (ether-block-amide) resin-1657 (PEBAX-1657)/silver nanoparticle (AgNPs)/7,7,8,8-tetracyanoquinodimethane (TCNQ) composite membranes were prepared for olefin/paraffin separation. The long-term performance of composite membranes can be improved by preventing the reduction of silver ions by adding Al(NO3 )3 and PEBAX-1657, which has 40% amide groups and 60% ether groups, to the polymer matrix for high permeance. In this study, silver ions were reduced to form nanoparticles to which 7,7,8,8-tetracyanoquinodimethane (TCNQ, electron acceptor) was added to produce long-term olefin carriers...
March 12, 2019: Scientific Reports
Megan A Jamiolkowski, Matthew C Hartung, Richard A Malinauskas, Qijin Lu
A reliable in vitro dynamic test method to evaluate device thrombogenicity is very important for the improvement of the design and safety of blood-contacting medical devices, while reducing the use of animal studies. In this study, a recirculating flow loop system was developed for thrombogenicity testing, using donor sheep blood anticoagulated with Anticoagulant Citrate Dextrose Solution A (ACDA) and used within 24-36 hr postdraw. Immediately before testing, the blood was recalcified and heparinized to a donor-specific target concentration...
February 19, 2019: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
Rongrong He, Shenzhen Cong, Jing Wang, Jindun Liu, Yatao Zhang
The computational simulation of porous graphene oxide (PGO) indicated that it has great potential for the preparation of gas separation membranes. However, scaling up the manufacture of multi-layer, defect-free porous graphene oxide membrane with consistently sized nanopores is extremely challenging. Here, we prepared layer-by-layer CO2-philic Pebax@1657 membranes that functionalized by o-hydroxyazo-hierarchical porous organic polymers (o-POPs) and PGO. The d-spacing of pristine PGO could be finely regulated through CO2-philic o-POPs to facilitate the permeability of CO2...
January 7, 2019: ACS Applied Materials & Interfaces
Roman Selyanchyn, Miho Ariyoshi, Shigenori Fujikawa
The effect of thickness in multilayer thin-film composite membranes on gas permeation has received little attention to date, and the gas permeances of the organic polymer membranes are believed to increase by membrane thinning. Moreover, the performance of defect-free layers with known gas permeability can be effectively described using the classical resistance in series models to predict both permeance and selectivity of the composite membrane. In this work, we have investigated the Pebax® -MH1657/PDMS double layer membrane as a selective/gutter layer combination that has the potential to achieve sufficient CO₂/N₂ selectivity and permeance for efficient CO₂ and N₂ separation...
December 2, 2018: Membranes
Haiyang Zhang, Ruili Guo, Jinli Zhang, Xueqin Li
Mixed matrix membranes (MMMs) have exhibited advantages in overcoming the trade-off effect, although it is still intensively demanded in the design of multifunctional fillers to improve CO2 separation performance. At present, MMMs with transport channels present an effective strategy to obtain ultrahigh CO2 permselectivity. In this work, Pebax-based MMMs was fabricated by incorporating nanocapsules (NCs), whose exterior, interior and transverse shell surfaces contained abundant carboxylic acid groups. NCs, similar to vesicles in cells, provide favourable physical and chemical microenvironments to the constructed CO2 transport channels, enhancing the CO2 permselectivity via both a facilitated transport mechanism and a solution-diffusion mechanism...
November 19, 2018: ACS Applied Materials & Interfaces
Baosheng Ge, Yanyan Xu, Haoru Zhao, Haixiang Sun, Yaoli Guo, Wenguang Wang
Mixed matrix membranes (MMMs) attract great attention due to their outstanding gas separation performance. The compatibility between the fillers and the polymer matrix is one of the key points for the preparation of high-performance MMMs. In this work, MMMs consisting of metal-organic frameworks (MOFs) of amine-modified Cu-BTC (NH₂-Cu-BTC; BTC = 1,3,5-benzenetricarboxylic acid) and submicrometer-sized amine-modified Cu-BTC (sub-NH₂-Cu-BTC) incorporated into a Pebax-1657 polymer were fabricated for the gas separation...
August 13, 2018: Materials
Gabriele Clarizia, Paola Bernardo, Giuliana Gorrasi, Daniela Zampino, Sabrina C Carroccio
Dense films based on the hydrophobic Pebax® 2533 were prepared by using solution casting in different solvents as well as compression molding and subjected to photo⁻aging under ultraviolet (UV) irradiation. The influence of the preparation method, including the casting solvents, as well as the UV irradiation time selected to treat the samples, were evaluated in terms of permeation rates of pure gases (CO₂, N₂, O₂, CH₄, He, and H₂). The transport data were correlated with the microstructure and surface properties by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), as well as water contact angle measurements...
July 31, 2018: Materials
Yatao Zhang, Yijia Shen, Jingwei Hou, Yiming Zhang, Winny Fam, Jindun Liu, Thomas Douglas Bennett, Vicki Chen
Block copolymer materials have been considered as promising candidates to fabricate gas separation membranes. This microphase separation affects the polymer chain packing density and molecular separation efficiency. Here, we demonstrate a method to template microphase separation within a thin composite Pebax membrane, through the controllable self-assembly of one-dimensional halloysite nanotubes (HNTs) within the thin film via the solution-casting technique. Crystallization of the polyamide component is induced at the HNT surface, guiding subsequent crystal growth around the tubular structure...
June 13, 2018: ACS Applied Materials & Interfaces
Anahid Sabetghadam, Xinlei Liu, Marvin Benzaqui, Effrosyni Gkaniatsou, Angelica Orsi, Magdalena M Lozinska, Clemence Sicard, Timothy Johnson, Nathalie Steunou, Paul A Wright, Christian Serre, Jorge Gascon, Freek Kapteijn
To gain insight into the influence of metal-organic framework (MOF) fillers and polymers on membrane performance, eight different composites were studied by combining four MOFs and two polymers. MOF materials (NH2 -MIL-53(Al), MIL-69(Al), MIL-96(Al) and ZIF-94) with various chemical functionalities, topologies, and dimensionalities of porosity were employed as fillers, and two typical polymers with different permeability-selectivity properties (6FDA-DAM and Pebax) were selected as matrices. The best-performing MOF-polymer composites were prepared by loading 25 wt % of MIL-96(Al) as filler, which improved the permeability and selectivity of 6FDA-DAM to 32 and 10 %, while for Pebax they were enhanced to 25 and 18 %, respectively...
June 4, 2018: Chemistry: a European Journal
Winny Fam, Jaleh Mansouri, Hongyu Li, Jingwei Hou, Vicki Chen
Blends containing ionic liquid (IL) 1-ethyl-3-methyimidazolium tetrafluoroborate [emim][BF4 ] gelled with Pebax 1657 block copolymers were modified by adding graphene oxide (GO) and fabricated in the form of thin film composite hollow fiber membranes. Their carbon dioxide (CO2 ) separation performance was evaluated using CO2 and N2 gas permeation and low-pressure adsorption measurements, and the morphology of films was characterized using scanning electron microscopy, atomic force microscopy, and transmission electron microscopy...
February 28, 2018: ACS Applied Materials & Interfaces
Jinpeng Hou, Xueqin Li, Ruili Guo, Jianshu Zhang, Zhongming Wang
To improve CO2 separation performance, porous carbon nanosheets (PCNs) were used as a filler into a Pebax MH 1657 (Pebax) matrix, fabricating mixed matrix membranes (MMMs). The PCNs exhibited a preferential horizontal orientation within the Pebax matrix because of the extremely large 2D plane and nanoscale thickness of the matrix. Therefore, the micropores of the PCNs provided fast CO2 transport pathways, which led to increased CO2 permeability. The reduced pore size of the PCNs was a consequence of the overlapping of PCNs and the polymer chains penetrating into the pores of the PCNs...
March 23, 2018: Nanotechnology
Vaishnavi Chandrasekar, Dustin W Janes, David M Saylor, Alan Hood, Akhil Bajaj, Timothy V Duncan, Jiwen Zheng, Irada S Isayeva, Christopher Forrey, Brendan J Casey
A novel approach for rapid risk assessment of targeted leachables in medical device polymers is proposed and validated. Risk evaluation involves understanding the potential of these additives to migrate out of the polymer, and comparing their exposure to a toxicological threshold value. In this study, we propose that a simple diffusive transport model can be used to provide conservative exposure estimates for phase separated color additives in device polymers. This model has been illustrated using a representative phthalocyanine color additive (manganese phthalocyanine, MnPC) and polymer (PEBAX 2533) system...
January 2018: Annals of Biomedical Engineering
Ehsan Ghasemi Estahbanati, Mohammadreza Omidkhah, Abtin Ebadi Amooghin
In this research, Pebax1657 as an organic phase and silver nanoparticles as an inorganic phase were used for preparation of binary mixed matrix membranes (MMMs). Silver nanoparticles as a filler could enter the polymer chains and enhance the gas permeability by increasing the fractional free volume of membranes. Afterward, ternary MMMs were fabricated by addition of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4 ]) ionic liquid, in order to have better polymer/filler adhesion and eliminate interfacial defects and nonselective voids...
March 22, 2017: ACS Applied Materials & Interfaces
Vaishnavi Chandrasekar, Dustin W Janes, Christopher Forrey, David M Saylor, Akhil Bajaj, Timothy V Duncan, Jiwen Zheng, Kausar B Riaz Ahmed, Brendan J Casey
Many polymeric medical device materials contain color additives which could lead to adverse health effects. The potential health risk of color additives may be assessed by comparing the amount of color additive released over time to levels deemed to be safe based on available toxicity data. We propose a conservative model for exposure that requires only the diffusion coefficient of the additive in the polymer matrix, D, to be specified. The model is applied here using a model polymer (poly(ether-block-amide), PEBAX 2533) and color additive (quinizarin blue) system...
January 2018: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
Yu Wu, Pan Jia, Linli Xu, Zhangyan Chen, Linhong Xiao, Jinhua Sun, Jun Zhang, Yong Huang, Christopher W Bielawski, Jianxin Geng
Here, we describe an in situ approach for growing polyepoxides from the surfaces of graphene oxide (GO) using a surface-initiated polymerization reaction. The polymerization methodology is facile and general as a broad range of epoxides carrying various functional groups have been successfully polymerized by simply adding GO powders in the epoxide monomers. The resultant polyepoxide grafted GO are found to show enhanced dispersibility in various common solvents and to exhibit increased d-spacing between the basal planes...
February 8, 2017: ACS Applied Materials & Interfaces
Mohammadmahdi Etemadi, Saman Samadi, Shabnam Sharif Yazd, Pooya Jafari, Negin Yousefi, Majid Aliabadi
In the present study, a novel Cr(6+)-imprinted Pebax/chitosan/GO/APTES nanofibrous adsorbent (Cr(6+)-PCGA) was prepared and its performance was compared with PCGA nanofibers for selective sorption of Cr(VI) ions from aqueous solutions. The prepared nanofibers were characterized using FTIR, SEM and EDAX analysis. The influence of batch sorption experiments including GO/APTES content, pH, contact time, Cr(VI) initial concentration and temperature on the Cr(VI) sorption efficiency using synthesized nanofibers was investigated...
February 2017: International Journal of Biological Macromolecules
Haiyang Zhang, Ruili Guo, Jinpeng Hou, Zhong Wei, Xueqin Li
In this study, a carbon nanotubes composite coated with N-isopropylacrylamide hydrogel (NIPAM-CNTs) was synthesized. Mixed-matrix membranes (MMMs) were fabricated by incorporating NIPAM-CNTs composite filler into poly(ether-block-amide) (Pebax MH 1657) matrix for efficient CO2 separation. The as-prepared NIPAM-CNTs composite filler mainly plays two roles: (i) The extraordinary smooth one-dimensional nanochannels of CNTs act as the highways to accelerate CO2 transport through membranes, increasing CO2 permeability; (ii) The NIPAM hydrogel layer coated on the outer walls of CNTs acts as the super water absorbent to increase water content of membranes, appealing both CO2 permeability and CO2 /gas selectivity...
October 26, 2016: ACS Applied Materials & Interfaces
Yijia Shen, Huixian Wang, Xiang Zhang, Yatao Zhang
Molybdenum disulfide (MoS2) is a graphene-like two-dimensional inorganic material, which has been used for the first time as an inorganic nanofiller to prepare a composite mixed matrix membrane to separate CO2 and N2. Polysulfone (PSf) was used as a support substrate and poly(dimethylsiloxane) (PDMS) was used as the gutter layer. The selective layer was prepared by mixing a CO2-philic copolymer Pebax 1657 with MoS2 nanosheets to enhance CO2 permeance. In addition, a simple drop-coating and evaporation method was developed to prepare the selective layer...
September 7, 2016: ACS Applied Materials & Interfaces
Sae Woon Sohn, Myounggyu D Noh, Jong-Hyun Lee, Kyoung Nam Kim, Chang-Sik Kim, Byung Heon Ahn
PURPOSE: We explored the performance of and pressure elevation caused by small-diameter microtubes used to reduce overfiltration. METHODS: Using a syringe pump-driven constant-flow setting (2 µL/min), pressures were measured for polytetrafluoroethylene (PTFE) microtubes 5 mm in length with inner diameters of 51, 64, and 76 µm and for polyether block amide (PEBAX) microtubes with an inner diameter of 76 µm. Experiments (using microtubes only) were initially performed in air, water, and enucleated pig eyes and were repeated under the same conditions using intraluminal 9/0 nylon stents...
June 2016: Korean Journal of Ophthalmology: KJO
Rachel Berry, Niranchan Paskaranandavadivel, Peng Du, Mark L Trew, Gregory O'Grady, John A Windsor, Leo K Cheng
BACKGROUND: Gastric slow waves regulate peristalsis, and gastric dysrhythmias have been implicated in functional motility disorders. To accurately define slow wave patterns, it is currently necessary to collect high-resolution serosal recordings during open surgery. We therefore developed a novel gastric slow wave mapping device for use during laparoscopic procedures. METHODS: The device consists of a retractable catheter constructed of a flexible nitinol core coated with Pebax...
January 2017: Surgical Endoscopy
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