Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
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Book Part Advances in Nanocomposite Membranes for CO2 Removal(Elsevier, 2024) Marpani,F.; Othman,N.H.; Alias,N.H.; Mat Shayuti,M.S.; Alsoy Altınkaya, SacideNanocomposite membranes have emerged as a promising solution for efficient carbon dioxide (CO2) removal in gas separation processes. These membranes combine polymeric matrices with inorganic nanofillers to synergize the excellent separation performance of inorganic materials with the mechanical stability of polymers. The choice of nanofillers, such as porous and nonporous materials, significantly influences the gas permeability and selectivity of the resulting nanocomposite membranes. Porous fillers with interstitial channels and large surface areas are found to selectively adsorb CO2, enhancing membrane separation performance. On the other hand, nonporous fillers alter the polymer chain orientation, influencing gas separation differently. The 1D, 2D, and 3D morphologies of nanofillers offer unique properties in terms of surface-to-volume ratio, permeability, and selectivity. The fabrication of nanocomposite membranes also plays a crucial role, and advances in materials and manufacturing techniques have enabled the design of high-performing membranes. Asymmetric and symmetric configurations have been explored to optimize separation efficiency. Nevertheless, challenges such as aging, compaction, and swelling need to be addressed to ensure the long-term stability of nanocomposite membranes. Future research should focus on developing advanced theoretical models to better predict gas permeation behaviors in these membranes. Overall, nanocomposite membranes offer a promising avenue for efficient CO2 removal, contributing to sustainable environmental practices and energy production. © 2024 Elsevier Ltd. All rights reserved.Article Citation - WoS: 4Citation - Scopus: 5Antifouling Polydopamine-Modified Poly (ether Sulfone) Membrane Immobilized With Alumina-Calcium Oxide Catalyst for Continuous Biodiesel Production(Elsevier, 2023) Güngörmüş, Elif; Şeker, Erol; Alsoy Altınkaya, SacideBiodiesel is an alternative biofuel that can be blended with conventional petroleum-derived diesel fuel to partly reduce the dependence on the imported oil. Catalytic membrane reactors are promising candidates for sustainable biodiesel production. Herein, we report a novel catalytically active polydopamine-modified poly (ether sulfone) (PES) membrane immobilized with an alumina-calcium oxide catalyst. The reaction temperature, butanol to canola oil ratio, and transmembrane pressure applied through the membrane were optimized with response surface methodology and Box-Behnken design. In contrast to all previous catalytic membrane studies for biodiesel production, we used butanol as a co-reactant to improve the winter problems of biodiesel made with methanol. FTIR and SEM-EDX analysis confirmed the successful immobilization of the catalyst. At the end of 30 days of storage in the reactant mixture, 95% of the catalyst loaded to the membrane was still on the surface, and biodiesel yield values and butanol flux of the membrane did not change. We compared the batch and flowthrough operation modes by measuring the catalytic activity of membranes under static and dynamic conditions within 24 h (8-cycle). The biodiesel yield under dynamic condition decreased in the first three cycles from 54.54 +/- 0.65% to 47.31 +/- 0.70% and then stayed constant, whereas a continuous decrease from 25.42 +/- 0.57% to 17.19 +/- 0.58% was observed under static condition. In each cycle, the equilibrium limitation for the yield was overcome only when the membrane was operated under pressure. The main reason for the decrease in catalytic activities was the fouling on the catalyst surface which was quickly removed by backwashing with butanol. It is concluded that catalytic membranes with antifouling properties and alcohol stability can make biodiesel production more cost-effective and environmentally friendly.Article Citation - WoS: 16Citation - Scopus: 15Ultrasound-Assisted Dopamine Polymerization: Rapid and Oxidizing Agent-Free Polydopamine Coatings on Membrane Surfaces(Royal Society of Chemistry, 2021) Cihanoğlu, Aydın; Schiffman, Jessica D.; Alsoy Altınkaya, SacideHerein, we report a controllable pathway to accelerate the polymerization kinetics of dopamine using ultrasound as a trigger. The use of ultrasound was demonstrated to dramatically accelerate the slow liquid phase reaction kinetics and increase the deposition rate of the polydopamine coating on the surface of polymeric membranes.Article Citation - WoS: 54Citation - Scopus: 62A Positively Charged Loose Nanofiltration Membrane Fabricated Through Complexing of Alginate and Polyethyleneimine With Metal Ions on the Polyamideimide Support for Dye Desalination(Elsevier, 2021) Metecan, Ayşe; Cihanoğlu, Aydın; Alsoy Altınkaya, SacideNowadays, loose nanofiltration (NF) membranes are preferred for dye desalination to achieve high dye/salt selectivity and enable filtration at low operating pressure. However, current fabrication techniques require rigorous reaction conditions and long preparation times. Herein, we used the chelating ability of the polyethyleneimine (PEI) and alginate with the metal ions to fabricate loose NF membranes via a facile approach. The positively charged polyamide imide (PAI)/PEI support was used to build the assembly. Direct attachment of Zn or Fe ions to the PEI chains did not result in a stable complex in the presence of a high salt concentration (1000 ppm NaCl). On the other hand, alginate coated on the support allowed building permanent assemblies after crosslinked with Fe3+ and Zn2+ transition metal ions. The PAI/PEI-Alg-Fe3+ membrane exhibited the highest permeability, excellent antifouling behaviour upon exposure to synthetic textile wastewater, and maintained long-term stability under static and dynamic conditions. Also, the same membrane rejected dyes and coloured substances in real wastewater sample during 72 h continuous filtration. With alginate metal complex formation on a suitable support, a scalable loose NF membrane was manufactured, demonstrating improved throughput value compared to current NF membranes.Article Citation - WoS: 14Citation - Scopus: 16Facile Fabrication of Anti-Biofouling Polyaniline Ultrafiltration Membrane by Green Citric Acid Doping Process(Elsevier, 2021) Güngörmüş, Elif; Alsoy Altınkaya, SacideThis study aimed to enhance the anti-biofouling property of the polyaniline (PANI) based ultrafiltration (UF) membrane by utilizing its self-acid doping ability. A naturally derived biodegradable agent, citric acid, was doped to the membrane by filtering at 1 bar. Acid doping increased the hydrophilicity, made the surface nearly electroneutral, and imparted biocidal characteristics to the membrane. Biofouling was simulated by filtering a suspension of E.coli and S.aureus through the membranes. Most fouling on the doped membrane was reversible and easily removed by simple washing, leading to a high flux recovery ratio. The SEM images taken after filtration and washing steps showed that the modified membrane surface was free of bacteria while many bacteria accumulated on the pristine membrane surface. The doped membrane was stored in 1 M NaCl solution for up to five months. A tiny amount of citric acid was lost from the membrane, and at the end of storage, the flux, rejection, and antibacterial activity values did not change, demonstrating the antibacterial agent's stability. The protocol proposed in this study is fast, simple, facile, and easily scalable for large-scale production. Using a green antibacterial agent and its loading with a one-step process without consuming chemicals or functionalizing the support makes the proposed method environmentally friendly.Conference Object Predicting Drying in Solvent-Coated Polymeric Films(American Chemical Society, 2000) Alsoy Altınkaya, Sacide; Duda, John Larry[No abstract available]Conference Object Development of Functional Materials for Sirna Delivery and Neural Tissue Engineering(AIChE, 2015) Uz, Metin; Alsoy Altınkaya, Sacide; Mallapragada, Surya K.The current nonviral siRNA delivery systems in the literature face many problems such as, cellular entry, endosomal escape and efficient siRNA release. Considering this motive, we developed gold nanoparticles (AuNPs) and temperature/pH responsive pentablock copolymer based siRNA delivery systems to address these problems. The temperature and pH responsive cationic and amphiphilic pentablock copolymers, which were consisted of the temperature responsive Pluronic F127 middle block constructed by PEO-PPO-PEO ((poly(ethyleneoxide)-block-poly(propyleneoxide)-block-poly(ethyleneoxide))) blocks contributing cellular entry through temperature responsive micellization and pH responsive cationic PDEAEM (poly(2-diethylaminoethyl methacrylate)) end blocks facilitating nucleic acid condensation and endosomal escape, were used for the first time in the development of polyplex and AuNP based multicomponent siRNA delivery systems (MCSs). The results indicated that systems managed to protect siRNA from external effects, maintain the system stability, facilitate cellular entry and enhance endosomal escape. It was noted that the transfection efficiency of the MCSs, which were boosted by the presence of cleavable disulfide bond, was ~15% higher than the commercial product RNAiMax while the efficacy of polyplexes alone were similar to the RNAiMax.Article Citation - WoS: 12Citation - Scopus: 13Development of Agcl-Tio2 Xerogels Entrapped Antibacterial Polyacrylonitrile Membranes: the Effect of High Salinity Water on Silver Release, Antibiofouling and Antibacterial Efficacies(Elsevier Ltd., 2020) Uz, Metin; Yaşar Mahlıçlı, Filiz; Şeker, Erol; Alsoy Altınkaya, SacideSilver-containing antibacterial membranes are commonly used to control biofouling during bacteria filtration. Unfortunately, fast and uncontrolled release of silver to water is a challenge since this causes mass accumulation of silver in water resources and insufficient long-term antimicrobial effect. To overcome these disadvantages, we propose to add AgCl-TiO2 xerogels (0–0.8 wt%) in the polyacrylonitrile membranes. The long-term silver retaining of the membranes was evaluated by measuring the silver release under filtration of deionized water in the absence and the presence of 1 M NaCl up to 5 days. The antibiofouling and the antibacterial efficacies were determined by measuring the changes in antibacterial activity and DI water flux of the membranes at the end of 5 days of E. coli filtration. The 0.2 wt% AgCl-TiO2 xerogel incorporated polyacrylonitrile membrane demonstrated a constant ~1 ?g of silver release/cm2 per filtration cycle after a total filtration of 0.05 L/cm2 with 1 M NaCl solution. Additionally, it showed antibacterial efficacy and ~100% recovery of deionized water flux by simple backwashing with water after having been used in many E. coli filtration cycles. Thus, this membrane could potentially be used up to ~5.8 years for 8000 h a year for the filtration of high salinity water. Statement of novelty: Silver-containing antibacterial membranes are commonly used to control biofouling during bacteria filtration. Uncontrolled release of silver from the membrane causes massive silver accumulation in water which in turn leads to contamination of water resources and threat to aquatic organisms. Although silver release is strongly influenced by the salinity of water, the release data was collected through filtration of pure DI water or tap water in literature. To overcome the shortcomings of the published studies, we propose to use AgCl-TiO2 xerogels in membranes due to low solubility of AgCl in water and measure the release by filtering high-salinity water. © 2020 Elsevier B.V.