Chiral separation has become a crucial topic for effectively utilizing superfluous racemates synthesized by chemical means and satisfying the growing requirements for producing enantiopure chiral compounds. However, the remarkably close physical and chemical properties of enantiomers present significant obstacles, making it necessary to develop novel enantioseparation methods. This review comprehensively summaries the latest developments in the main enantioseparation methods, including preparative-scale chromatography, enantioselective liquid–liquid extraction, crystallization-based methods for chiral separation, deracemization process coupling racemization and crystallization, porous material method and membrane resolution method, focusing on significant cases involving crystallization, deracemization and membranes. Notably, potential trends and future directions are suggested based on the state-of-art “coupling” strategy, which may greatly reinvigorate the existing individual methods and facilitate the emergence of cross-cutting ideas among researchers from different enantioseparation domains.

Strategies for chiral separation: from racemate to enantiomer

Highly sensitive ratiometric biosensors have attracted much attention in biomarker detection, but most rely on single-mode signals, which can affect accuracy. The development of new principles and methods for dual-mode ratiometric sensing can enhance detection accuracy. Herein, the zinc(II) meso-tetra(4-carboxyphenyl) porphyrin/MXene (ZnTCPP/Ti3C2Tx) hybrids with phosphate-induced stimuli-responsive behavior are used to develop a novel dual-mode fluorescent/electrochemiluminescent (FL/ECL) ratiometric biosensor. The composites exhibit FL quenching and enhanced ECL behavior involving dissolved O2. The FL quenching of ZnTCPP/Ti3C2Tx is caused by energy transfer (EnT) and photo-induced electron transfer (PET) from ZnTCPP to Ti3C2Tx. While the introduction of MXene compensates for the inadequate conductivity of ZnTCPP, facilitating electron transfer, which further makes the surface ZnTCPP more capable of activating O2 to produce singlet oxygen (1O2), thereby generating enhanced cathodic ECL. Furthermore, phosphate ions (PO43−) can interact with the Ti sites of ZnTCPP/Ti3C2Tx, leading to competition for coordination with ZnTCPP, which in turn detaches ZnTCPP, resulting in enhanced FL and reduced ECL. On the basis of the phosphate-induced stimuli-responsive behavior, the dual-mode FL/ECL ratiometric biosensing of alkaline phosphatase (ALP) is achieved through ALP-catalyzed production of PO43− cascade effect with ZnTCPP/Ti3C2Tx. The linear detection range for ALP is 0.1–50 mU/mL, with a detection limit as low as 0.0083 mU/mL. This proposed ZnTCPP/Ti3C2Tx composites with stimuli-responsive behavior is expected to provide new ideas for the development of high-sensitivity dual-mode ratiometric biosensors with promising applications in the precise detection of important biomarkers. 

Zinc porphyrin/MXene hybrids with phosphate-induced stimuli-responsive behavior for dual-mode fluorescent/electrochemiluminescent ratiometric biosensing.

Emerging highly selective MXene-based membranes have drawn a greater scientific interest in the field of water treatment due to their ion-selective and controlled molecular transport characteristics. However, MXene-based membranes have limitations in water treatment due to the difficulties including permeability-selectivity trade-off, swelling, fouling, oxidation, etc. Thus, a better understanding of the rational structural design principles of the membranes and their separation mechanisms are essential to further their development in water treatment. This review provides a concise overview of the key timeline in the fabrication of MXene-based membranes, the membrane characterization approaches used to understand their structure-property correlations, and the present difficulties in synthesizing high-performance MXene-based membranes. To overcome these challenges, new designing approaches are comprehensively reviewed to enhance the permeability, selectivity, stability, and antifouling properties of MXene-based membranes. These approaches include physical intercalation, chemical cross-linking, membrane surface modification, etc. Then, the separation mechanisms involved in the membranes in water treatment are presented, followed by the related applications. Looking forward, the perspective is provided on the future research directions for further advancing the membranes. This timely review may help to bridge the gap between academic research and industrial needs of MXene-based membranes for water treatment. 

MXene-based membranes in water treatment: Current status, and future prospects

High emission of carbon dioxide (CO2) has caused CO2 levels to reach more than 400 ppm in air and led to a serious climate problem. In addition, in confined spaces such as submarines and aircraft, the CO2 concentration increase in the air caused by human respiration also affects human health. In order to protect the environment and human health, the search for high-performance adsorbents for carbon capture from high and low concentration gas is particularly important. Porous carbon materials, possessing the advantages of low cost and renewability, have set off a boom in the research of porous adsorbents, which have the opportunity to be utilized on a large scale for industrial carbon capture in the future. In this review, we summarize the recent research progress of porous carbons for carbon capture from flue gas and directly from air in the last five years, including activated carbon (AC), heteroatom-modified porous carbon, carbon molecular sieves (CMS), and other porous carbon materials, with a focus on the effects of temperature, water content, and gas flow rate of industrial flue gas on the performance of porous carbon adsorbents. We summarize the preparation strategies of various porous carbons and seek environmental friendly porous carbon materials preparation strategies under the premise of improving the CO2 adsorption capacity and selectivity of porous carbon adsorbents. Based on the effects of real industrial flue gas on adsorbents, we provide new ideas and evaluation methods for the development and preparation of porous carbon materials.

Recent Progress on Porous Carbons for Carbon Capture.

A significant proportion of pharmaceutical compounds used in daily applications are chiral in nature, wherein optical enantiomers possess analogous physical and chemical properties but may exhibit distinct therapeutic effects. Consequently, considerable scholarly attention has been directed toward the development of enhanced methodologies for the production and separation of enantiomers. Among these methodologies, membrane separation technology has emerged as a highly promising approach for industrial chiral separation applications. However, the preparation of more efficient chiral membranes remains a formidable challenge, necessitating the advancement of preparation methods. Various techniques have been devised for the preparation of chiral solid membranes, encompassing electrostatic spinning, interfacial polymerization, surface graft modification, in-situ growth, and phase inversion methods. Despite the availability of these techniques, comprehensive summaries comparing their distinctions and advantages are scant. This review aims to provide a systematic synthesis and comparative analysis of different preparation processes. It is anticipated that this elucidation of preparation technologies will foster further advancements in chiral membrane research and facilitate progress in the field of chiral materials. 

Fabrication and application of chiral separation membranes: A review

Nanoconfinement enabled non-covalently decorated MXene membranes for ion-sieving

Membrane-based enantioselective separation is a promising method for chiral resolution due to its low cost and high efficiency. However, scalable fabrication of chiral separation membranes displaying both high enantioselectivity and high flux of enantiomers is still a challenge. Here, we report the preparation of homochiral porous organic cage (CC3-R)-based enantioselective thin-film-composite membranes using polyamide (PA) as the matrix, where fully organic and solvent-processable cage crystals have good compatibility with the polymer scaffold. The hierarchical CC3-R channels consist of chiral selective windows and inner cavities, leading to favorable chiral resolution and permeation of enantiomers; the CC3-R/PA composite membranes display an enantiomeric excess (ee) of 95.2% for R-(+)-limonene over S-(-)-limonene and a high flux of 99.9 mg h-1 m-2. This work sheds light on the use of homochiral porous organic cages for preparing enantioselective membranes and demonstrates a new route for the development of next-generation chiral separation membranes. This article is protected by copyright. All rights reserved.

A Homochiral Porous Organic Cage-Polymer Membrane for Enantioselective Resolution.

High‐performance proton exchange membranes (PEMs) play a vital role in the efficiency of high‐temperature proton exchange membrane fuel cells. In this study, a novel PEM with a hyperbranched interpenetrating hydrogen bond network (HIHBN) is developed by incorporating hyperbranched poly(benzyl‐triptycene) (PBT) and SnP2O7 hydrogen bond networks. This innovative design significantly enhances the proton conductivity. Additionally, the unique structure of the hyperbranched PBT polymer with a branching point (triptycene, a π‐conjugated aromatic ring compound with a three‐cyclic configuration) contributes to an impressive glass transition temperature exceeding 400 °C, enabling the membrane to operate at elevated temperatures (above 220 °C) in fuel cell applications. This membrane shows promise as an alternative to commonly used polybenzimidazole (PBI)‐based membranes, offering improved mechanical strength and a reduced swelling ratio. When applied in fuel cells, the HIHBN PEM achieves an excellent through‐plane proton conductivity of 0.108 S cm−¹ and a peak power density of 0.75 W cm−2 at 220 °C under dry H2/O2 conditions. Notably, it exhibited minimal degradation after ≈33 h under harsh operating conditions, demonstrating its stability and long‐term durability. These findings highlight the potential of HIHBN PEMs for high‐efficiency, durable performance in high‐temperature fuel cell environments.

Hyperbranched Interpenetrating Hydrogen Bond Network (HIHBN) Proton Exchange Membrane for Fuel Cells Above 220 °C

To investigate the changes in colonic pouch function and retention rate after ileal pouch-anal anastomosis in elderly patients with ulcerative colitis: a multicenter retrospective analysis.

Chiral separation membranes have shown great potential for efficient separation of racemic mixtures into enantiopure components for many applications such as in food and pharmaceutical industries; however, scalable fabrication of membranes with both high enantioselectivity and flux remains a challenge. Herein, enantiopure S -poly(2,4-dimethyl-2-oxazoline) ( S -PdMeOx) macromonomers were synthesized and used to prepare a new type of enantioselective membrane consisting of a chiral S -PdMeOx network scaffolded by graphene oxide (GO) nanosheets. The S -PdMeOx-based membrane showed near-quantitative enantiomeric excess ( ee ) (98.3 ± 1.7%) of S -(-)-limonene over R -(+)-limonene and a flux of 0.32 mmol m -2 h -1 . This work demonstrates the potential of homochiral poly(2,4-disubstituted-2-oxazoline)s in chiral discrimination and provides a new route to the development of highly efficient enantioselective membranes using synthetic homochiral polymer networks.

Homochiral poly(2-oxazoline)-based membrane for efficient enantioselective separation.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Kaiqiang He

Author Tools

Chat about Author

Papers

Nanoconfinement enabled non-covalently decorated MXene membranes for ion-sieving

A Homochiral Porous Organic Cage-Polymer Membrane for Enantioselective Resolution.

Hyperbranched Interpenetrating Hydrogen Bond Network (HIHBN) Proton Exchange Membrane for Fuel Cells Above 220 °C

To investigate the changes in colonic pouch function and retention rate after ileal pouch-anal anastomosis in elderly patients with ulcerative colitis: a multicenter retrospective analysis.

Homochiral poly(2-oxazoline)-based membrane for efficient enantioselective separation.