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![‘Nanoporous’ membranes from phase separated polystyren-block-polylactide (PSt-b-PL) copolymers with varied copolymer structure (molar mass in kg/mol, molar fraction of PL), after selective hydrolysis of the PL phase: (a) 32, 0.28 (Dcyl=15nm), (b) 58, 0.38 (Dcyl=31nm), (c) 92, 0.36 (Dcyl=45nm), (d) 40, 0.42 (Dcyl=42nm)—the diameter of the cylinder, Dcyl, as determined by SAXS agrees well with the pore diameter found from SEM (reprinted with permission from [171], Copyright (2002) American Chemical Society).](profile/Mathias-Ulbricht/publication/222122862/figure/fig6/AS:269540802166796@1441274943725/Nanoporous-membranes-from-phase-separated-polystyren-block-polylactide-PSt-b-PL.png)
‘Nanoporous’ membranes from phase separated polystyren-block-polylactide (PSt-b-PL) copolymers with varied copolymer structure (molar mass in kg/mol, molar fraction of PL), after selective hydrolysis of the PL phase: (a) 32, 0.28 (Dcyl=15nm), (b) 58, 0.38 (Dcyl=31nm), (c) 92, 0.36 (Dcyl=45nm), (d) 40, 0.42 (Dcyl=42nm)—the diameter of the cylinder, Dcyl, as determined by SAXS agrees well with the pore diameter found from SEM (reprinted with permission from [171], Copyright (2002) American Chemical Society).
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This feature article provides a comprehensive overview on the development of polymeric membranes having advanced or novel functions in the various membrane separation processes for liquid and gaseous mixtures (gas separation, reverse osmosis, pervaporation, nanofiltration, ultrafiltration, microfiltration) and in other important applications of mem...
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In relation to some inorganic membranes, polymeric membranes have relatively low separation
performance. However, the processing flexibility and low cost of polymers still make them highly attractive
for many industrial separation applications. Polymer–inorganic hybrid membranes constitute an emerging
research field and have been recently developed...
Citations
... This occurs because semipermeable membranes possess pores or structures that exclusively permit molecules of a certain size and polarity to pass through. Typically, semipermeable membranes have pores with sizes ranging from approximately 1 nanometer to 10 nanometers [20], [22]. Solutions containing solutes with larger and more complex molecules encounter difficulty passing through the pores of semipermeable membranes, particularly when the size or polarity of the solute molecules doesn't align with the membrane's structure [19], [20]. ...
In chemistry, there are three levels of representation namely macroscopic, submicroscopic, and symbolic. Chemistry is a branch of science that requires students to have an understanding of concepts and mathematical skills, one of which is colligative properties. The aim of this research is to analyze the concept of colligative properties so that students don't have misconceptions and can enhance their understanding through a multi-representation approach. The method used is the scientific approach, based on a series of five main learning experiences: Observing, Questioning, Reasoning, Associating, and Communicating. Information collection techniques include concept maps, concept analysis, and propositions. Colligative properties consist of vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure. The van't Hoff factor is present in most colligative properties where the solute is an electrolyte substance.
... The transport properties of a membrane for distinct components in a mixture dictate its role in a separation process. The separation method does not require any chemicals, operates at low temperatures, and consumes very little energy [25]. Membranes are also the most environmentally friendly branch of separation technology due to its nontoxic content. ...
BIOCHEMICAL INVESTIGATION OF MUSHROOM
... Typical membrane templates made by phase separation usually suffer from irregular porous structures in random distribution. 18 In contrast, the tracketched 19,20 and anodic aluminium oxide (AAO) 21,22 membranes feature the narrower hole-size distribution and lower tortuosity. However, the use of nuclear ssion or corrosive chemicals induces laborious procedures and undesirable contaminations. ...
Material patterning through templates has provided an efficient way to meet the critical requirement for surface function in various fields. Here, we develop a self-releasing photolithographic process to make large-area freestanding templates with precise patterns. The low surface energy of substrates by hydrophobic treatment with proper silane modification ensures the template self-releasing. This method eliminates the need of mechanical separation or any sacrificial layers. Major steps including UV exposure and baking are optimized to realize high-quality structures and the final release of templates. The negative photoresists of SU-8 and polyimide are chosen to confirm the feasibility of this process. Wafer-scale freestanding templates with uniform microhole arrays are obtained with high structural fidelity, smooth surfaces and excellent flexibility. The hole size ranges from several to several tens of micrometers with an extremely low variation (<1%). These advantages could promote the application of precisely structured templates for surface patterning in material and surface science.
... Track-etched membranes (TeMs) have the potential to be used as universal and cost-effective flexible sensors for a variety of applications including environmental monitoring, medical diagnostics, and food safety [2,3]. In general, choice of material for TeMs used in sensor systems depends on the specific requirements of the application, including pore size, shape, and chemical or biological function [4][5][6][7][8]. ...
As a result of anthropogenic activities, the environment is polluted by heavy metals. The most important task is to find methods to control their content in water. Track-etched membranes (TeMs) can be relatively easily modified by nanometer layers of functional materials with using the Langmuir ‒ Blodgett technique, which makes it possible to specifically change the structural, selective properties of the membrane surface and obtain new materials with desired properties. The aim of the work was to develop flexible sensors for the analysis of lead ions in water based on poly(ethylene terephthalate) (PET) TeMs with perfluorodecanoic acid (PFDA) nanolayers. Techniques for modifying TeMs based on PET with a monolayer coating based on PFDA by the Langmuir ‒ Blodgett method, and with two-layer coatings, formed by soaking PET TeMs/PFDA in xylenol orange solutions have been developed. The microstructure and local mechanical properties of the sensor surface were studied by atomic force microscopy, and the wettability and values of the specific surface energy of PET TeMs before and after modification were evaluated using the ''sessile'' drop method. Based on the measurement of electrochemical characteristics, it was found that PET TeMs/PFDA have a higher response of electrochemical characteristics compared to PET TeMs and PET TeMs/PFDA/XO. The limit of detection for lead ions in aqueous solutions at pH = 12 was of 0.652 µg/l within 5 measurements.
... In contrast, polymeric membranes are preferred due to their greater flexibility, good pore-forming properties, mechanical strength, chemical stability, high selectivity, and inexpensive materials for their synthesis [7]. Different pressurized filtration processes such as ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) are used in many industries (gas separation, drug delivery, and wastewater treatment) [5,8,9]. ...
Membrane technology offers several advantages in comparison to traditional separation methods, including enhanced removal capacity, operational flexibility, and cost-effectiveness. Nevertheless, the widespread adoption of membrane technology is hindered primarily by the issue of membrane fouling. So, this article provides an overview of various techniques employed in the fabrication and modification of nanocomposite membranes, specifically mixed matrix membranes (MMMs) by incorporation of carbon nanotubes (CNTs). This study examines the influence of CNTs on the intrinsic properties of membranes (pore morphology, porosity, pore size, hydrophilicity/hydrophobicity, membrane surface charge, and roughness). Additionally, the performance of membranes is evaluated in terms of flux permeation, contaminant rejection, and anti-fouling and antibacterial capability. Moreover, the long-term operation and leachability of the fabricated membranes were also discussed. Finally, the challenges and future works in developing MMMs with CNTs as nanofillers are discussed. The text offers a comprehensive overview of the interrelationships between fabrication methods, membrane functionality, and membrane efficiency in various water and wastewater treatment processes. It includes a wealth of supporting evidence and illustrative examples to facilitate the reader’s comprehension of these fundamental connections.
Graphical Abstract
... Sustainable polymer materials, relying both on biobased feedstocks and biodegradable polymers, have become a central research topic in the recent decade [1,2]. Applications of high-performance materials range from chemistry to medicine, diagnostics, packaging, energy, and electronics [3][4][5][6][7][8]. To replace existing petroleum-based polymers, sustainable feedstock-based compounds must exhibit at least similar or even improved properties compared to the materials available at present. ...
... To control effectively the humidification in fuel cell systems, external membrane humidifiers are used without increasing parasitic power. The membrane installed in fuel cell systems could be classified by shape, including flat sheet, hollow fiber, and hollow capsule [7,8]. The flat sheet has very high specific surface areas and can be stacked with many layers to be a module; however, it cannot withstand high pressure. ...
... 6,7 Membranes are widely used materials in industrial, agricultural, and medical fields for their outstanding separation and purification performance. [8][9][10] Biocatalytic membrane reactors (BMRs) are membranes with immobilized enzymes, which combine the separation functions of the membranes with the catalytic abilities of the enzymes. [11][12][13] Various approaches have been employed to prepare BMRs, including covalent bonding, adsorption, or encapsulation. ...
Biocatalytic membranes combine the separation properties of membranes and the catalytic abilities of enzymes, holding great promise for industries where both purification and conversion are required. In this work, polyelectrolyte...
... Organic membranes can be separated in two main categories, the integrally skinned membranes and the thin-film composite membranes. To the first category belong the porous polymeric membranes (i.e., MF/UF) which have been used for various water treatment processes, including water and wastewater filtration and water pretreatment for NF or RO membranes [19,20]. These membranes have an integrally skinned, often asymmetric structure, consisting of an open porous support layer beneath a relatively thin, less porous, skin layer of the same material t0010 Table 17.1 Membrane classification by pore type and target species [13]. ...
... p0070 Finally, two other promising membrane types for water treatment applications are the aquaporin membranes [24,25] and the vertically aligned nanotube membranes [26,27]. In addition, electrodialysis, an electrically driven desalination method using ionexchange membranes and membrane distillation, a thermally driven desalination process, are two other technologies with high impact in water treatment applications [20]. Although the research community is still working hard on the development of new modern and promising materials, as candidates for water membrane technology, there f0020 Figure 17.3 Membrane processes for water purification and desalination [22,23]. ...
... Polymer membranes are usually prepared using NIPS (Jung et al. 2016;Dong et al. 2018;Wang et al. 2019), TIPS (Li et al. 2006Rajabzadeh et al. 2009;Roh et al. 2010), evaporation-induced (Song et al. 2018;Plisko et al. 2019;Asad et al. 2020) or vaporinduced phase separation (VIPS) (Tsai et al. 2006;Barambu et al. 2020;Ismail et al. 2020). The selection of the method depends on the polymer properties and desired morphology of the membrane (Ulbricht 2006). In NIPS, a porous membrane with a finger-like structure is produced via immediate phase separation of the cast solution in a non-solvent. ...
Bio-based polymers and their derivatives are promising green alternatives to petroleum-based polymers in the preparation of membranes. In this study, we developed microfiltration membranes based on acetylated cellulose ether (ACE), a high-molecular-weight cellulose-derived biopolymer, using vapor-induced phase separation. The properties of these membranes were analyzed and compared with those of a commercial cellulose acetate (CA) membrane. The pore sizes and pore distributions of the ACE membranes were controlled by the polyethylene glycol additives used in the preparation of the membranes. The ACE membranes with pore sizes of 0.20–0.53 μm were effective in removing Escherichia coli bacteria, demonstrating their viability in sterilization applications. The ACE membrane also exhibited high pure water permeance values (25,000 L m⁻² h⁻¹ bar⁻¹) and lower non-specific protein binding compared to those of the commercial CA membrane. We believe that our study findings will promote the use of bio-based ACE membranes in commercial applications.
Graphical Abstract
