Carbonaceous Deposits in a Fuel-Film-Cooled Rocket Combustor: Optical Profilometry

A commercial thin film composite (TFC) polyamide (PA) reverse osmosis membrane was grafted with 3-sulfopropyl methacrylate potassium (SPMK) to produce PA-g-SPMK by atom transfer radical polymerization (ATRP). The grafting of PA was done at varied concentrations of SPMK, and its effect on the surface composition and morphology was studied by Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), optical profilometry, and contact angle analysis. The grafting of hydrophilic ionically charged PSPMK polymer brushes having acrylate and sulfonate groups resulted in enhanced hydrophilicity rendering a reduction of contact angle from 58° of pristine membrane sample labeled as MH0 to 10° for a modified membrane sample labeled as MH3. Due to the increased hydrophilicity, the flux rate rises from 57.1 L m−2 h−1 to 71.2 L m−2 h−1, and 99% resistance against microbial adhesion (Escherichia coli and Staphylococcus aureus) was obtained for MH3 after modification

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

Nanomaterials ◽

10.3390/nano11030607 ◽

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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Characterization of Carbonaceous Deposits on an End-of-Life Engines for Effective Cleaning for Remanufacturing

Sustainability ◽

10.3390/su13020950 ◽

2021 ◽

Vol 13 (2) ◽

pp. 950

Author(s):

Xing Wang ◽

Jianfeng Li ◽

Xiujie Jia ◽

Mingliang Ma ◽

Yuan Ren

Keyword(s):

End Of Life ◽

Sustainable Manufacturing ◽

Hybrid Structure ◽

Nuclear Magnetic Resonance Study ◽

Carbonaceous Deposit ◽

X Ray ◽

Cleaning Method ◽

Carbonaceous Deposits ◽

Strong Adhesion

Remanufacturing is one of the most effective strategies to achieve sustainable manufacturing and restore the performance of end-of-life products. However, the lack of an effective cleaning method to clean carbonaceous deposits severely hampers the remanufacturing of end-of-life engines. To explore an appropriate cleaning method, it is necessary to first study the characterization of the carbonaceous deposits. A broad range of analyses including X-ray fluorescence spectrometry, thermogravimetric analysis, 1H-nuclear magnetic resonance study, X-ray diffraction analysis, and scanning electron microscopy were performed to conduct an in-depth characterization of the carbonaceous deposits. The results showed that a hybrid structure composed of organics and inorganics is the most distinguishing feature of the carbonaceous deposit in end-of-life engines. The inorganics form the skeleton on which organics get attached, thereby resulting in a strong adhesion of the deposit and increasing the difficulty of cleaning. Therefore, a method in which several cleaning forces can be simultaneously applied is more suitable for the present purpose. Molten salt cleaning was chosen to verify the feasibility of this proposal. This method was shown to have the potential to effectively clean the carbonaceous deposit. This finding could contribute towards promoting the effective remanufacturing of end-of-life engines.

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Investigation of the Splat Deposition Behavior onto a Composite Coating in Cold Spray

Materials Science Forum ◽

10.4028/www.scientific.net/msf.941.1639 ◽

2018 ◽

Vol 941 ◽

pp. 1639-1644

Author(s):

Xin Chu ◽

Phuong Vo ◽

Stephen Yue

Keyword(s):

Electron Microscope ◽

Composite Coating ◽

Cold Spray ◽

Spray Deposition ◽

Cold Spraying ◽

Single Component ◽

Optical Profilometry ◽

Deposition Behavior ◽

Polished Substrate ◽

Scanning Electron

The splat test is usually generated by low feed rate cold spraying of particles onto an as-polished substrate and it can be considered as a monolayer coating deposition. In this study, in order to investigate cold spray deposition mechanisms, Fe splats were sprayed onto the cold-sprayed single component 316L, Fe, and a composite 90Fe coatings. Results showed that although there is only 3.6 vol.% of 316L in the composite 90Fe coating, Fe splats exhibit a much better deposition behavior onto the 90Fe as compared with the single component Fe coating. To explain this observation, Fe splat samples were characterized using the scanning electron microscope (SEM), optical profilometry, splat adhesion tests, and splat nanoindentation. Finally, a preliminary explanation towards the Fe splat deposition behavior onto the composite coating was drawn.

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