Molecularly imprinted polymer (MIP) technology and its prospective used in the surveillance of the environment are the focus of this review article, which aims to give an in-depth understanding of the field. The approach of generating highly cross-linked polymeric structures with effective binding sites that precisely match the analyte of interest by templating with it is covered in the study as a means of producing biomimetic ligands. It also highlights the stability and robustness of MIPs, making them ideal for challenging environmental conditions. The originality of this paper lies in its exploration of various physical forms and synthesis techniques of MIPs, as well as the development of specialized MIPs to address specific challenges. It emphasizes the diverse applications of MIPs in environmental monitoring, including sample pretreatment, solid-phase extraction, microextraction, sensors, and chromatographic separations with the discussion on integration of MIPs with advanced analytical tools, highlighting the potential for enhancing the accuracy and reliability of environmental monitoring. Furthermore, the integration of MIPs with advanced analytical instruments opens up new possibilities for qualitative and quantitative evaluation of detection systems. Capillary electrochromatography and thin-layer chromatography are mentioned as the examples of analytical techniques that can be seamlessly integrated with MIPs. This integration enables improved accuracy and reliability in environmental monitoring, enhancing our understanding and protection of the environment. It not only explores the fundamentals of MIP technology but also delves into the synthesis methods, specialized MIPs, and integration with advanced analytical instruments. By providing this holistic view, the paper offers a valuable resource for researchers and practitioners interested in utilizing MIPs for environmental monitoring applications.
Show more
A study of the self-healing capabilities of 2-aminophenyl disulfide (AFD)/epoxy systems is carried out. It has been observed that an excess of AFD promotes an increase of both the storage modulus and the glass transition temperature (Tg) due to an increase of the cross-link density. Concerning the self-healing properties, every AFD/epoxy system shows very good healing efficiencies (above 90%) with no prevalent differences among the different stoichiometries. Furthermore, CNT addition induces an increase of the storage modulus when there is no excess of AFD, but no significant effect is observed on the Tg. In addition, the incorporation of these nanoparticles allows thermal activation by the Joule effect. The results of self-healing tests under convective and resistive heating show similar healing efficiencies (all above 94%). Here, the thermal activation by Joule’s heating presents a lower power consumption and allows localized repair, which is very promising for this type of application.
Show more
The application of ordinary epoxy resins is severely limited by their poor dielectric properties and toughness, and the increasing focus on sustainability calls for raw materials to be renewable. Thus, a resveratrol-based compound (AE-Res) with three active ester structures was prepared and used to cure glycidyl ethers of bisphenol A (DGEBA) and a liquid crystal epoxy monomer (BPDGE). Test results showed that the combination (AE-Res/BPDGE) of resveratrol derivatives with liquid crystal epoxy monomers exhibited an excellent comprehensive performance. The mechanical strength and toughness of AE-Res/BPDGE were improved. Specifically, the tensile strength, elongation at break, flexural strength, and impact strength of AE-Res/BPDGE were 108.45 MPa, 12.31%, 159.92 MPa, and 39.51 kJ/m2, which were 48.14, 164.16, 92.51, and 143.74% higher than that of BPDGE cured by commercial methylhexahydrophthalic anhydride (MHHPA), respectively. This can be attributed to the introduction of a rigid structure and flexible ether bonds generated after curing. Meanwhile, the dielectric constant (Dk) of AE-Res/BPDGE decreased from 3.81 to 3.00 (10 MHz) compared to MHHPA/BPDGE, mainly owing to the enhanced d-spacing (4.69 vs 4.45 Å) and the absence of highly polar hydroxyl groups. In addition, AE-Res/BPDGE also exhibited good thermal stability and hydrophobicity with a T5% of 383.22 °C, a water contact angle of 110°, and a water absorption of 0.15% because of the presence of a rigid conjugated stilbene and biphenyl structure. Due to its ease of synthesis and environmental friendliness, AE-Res could be a satisfactory alternative to commercial epoxy curing agents.
Show more
Adding copolymerizable components into thermosetting resins is a common strategy to improve the thermal and mechanical properties of thermosets. However, it remains quite challenging to discover a universal copolymerizable additive that is applicable for various thermosetting systems. Here, the flexible molecular design of benzoxazine allows us to design a biobased benzoxazine monomer (CHR-ac) with several smart functionalities, which can copolymerize with various traditional thermosetting systems, including benzoxazine, epoxy, and bismaleimide resins. CHR-ac has been synthesized using paraformaldehyde, 3-aminophenylacetylene, and natural renewable chrysin as raw materials via the Mannich condensation. Specifically, the built-in intramolecular hydrogen bonding in CHR-ac results in a low polymerization temperature while it still maintains the advantage of long shelf life. In addition, the phenolic hydroxyl and acetylene groups in CHR-ac enable it to cross-link with well-commercialized thermosetting resins and significantly enhance their performance through the formation of highly cross-linked networks. Potentially, the rationally designed biobased benzoxazine in the current work can be used as a generic additive in thermosetting resins for applications spanning from the microelectronic to the aerospace industries.
Cited: 40
Show more
The simple, high-performance, and flame-retardant modification method is significantly important for the effective utilization of wood. In this work, ammonium polyphosphate (APP) and waterborne epoxy resin (WEP) were used for the treatment of fast-growing poplar by vacuum pressure impregnation to resolve the flammability, poor dimensional stability, and low mechanical strength problems. The results showed that 5A-E-Wood had strong self-extinguishing properties and passed the UL-94 V-0 combustion test, and the limiting oxygen index (LOI) value can reach 32.1%. Furthermore, the residue char weight of 5A-E-Wood reached 41.07%, which significantly promoted char-forming. Especially, the cone results showed a low heat release rate and an excellent smoke suppression effect. In addition, the incorporation of APP/WEP into wood can reduce water uptake (WU) and equilibrium moisture content (EMC), significantly improving dimensional stability and mechanical properties. Most important of all, the weight leaching ratio (WLR) of APP was extremely reduced. Therefore, this research presented that the mechanical properties and flame retardancy of the wood improved visibly due to the successful penetration of APP and WEP into the wood cell, which laid the foundation of its use as a high-performance wood-based material.
Cited: 37
Show more
Water recycling is one of the most sustainable solutions to growing water scarcity challenges. However, wastewaters usually contain organic pollutants and often are at extreme pH, which complicates the treatment of these streams with conventional membranes. In this work, we report the synthesis of a robust membrane material that can withstand prolonged exposure to extreme pH (of 1 or 13 for 2 months). Polyamine thin film composite (TFC) membranes are prepared in situ by interfacial polymerization between 1,3,5-tris(bromomethyl)benzene (tBrMeB) and p-phenylenediamine (PPD). Contrary to conventional polyamide TFC membranes, enhanced pH stability is achieved by eliminating the carbonyl groups from the polymer network. The membranes showed pure water permeance and molecular weight cutoff (MWCO) of 0.28 ± 0.09 L m–2 h–2 bar–1 and 820 ± 132 g mol–1, respectively. The membrane performance is further enhanced by manipulating the monomer structures and replacing p-phenylenediamine with m-phenylenediamine, resulting in a higher permeance of 1.3 ± 0.3 L m–2 h–1 bar–1 and a lower MWCO of 566 ± 43 g mol–1. Given the ease of fabrication and excellent stability, this chemistry represents a step forward in the fabrication of robust membranes for industrial wastewater recycling.
Cited: 37
Show more
N-Nitrosamine-derived nitric oxide (NO) delivery agents find widespread use in diverse biomedical applications, including cancer therapy. To understand how NO is released from these compounds and acts within cells, herein, we report a facile approach to synthesize N-nitrosamine-bound water-soluble napthalimide-based block copolymers (BCPx-NO) with improved regulation over their molecular weight and aqueous solution self-assembly. These polymers exhibit a fluorescence “turn-on” response upon photostimulated (365 nm, 3.71 mW/cm2) NO release, delivering 47–53 μM of NO within 10 h, while their concentration varied from 0.26 to 0.60 mg/mL. This accounts for approximately 67–75% of the theoretically bound NO within the polymers. The fluorescence “turn-on” response is characteristic of the small-molecule NO donor (NOD), although the emission time has a longer half-life in the polymers. The type of NO released from the NOD is a nitric oxide radical (•NO), as per the electron paramagnetic resonance spectroscopy results. The in vitro NO release in response to the photoirradiation and the consequent acquired fluorescence are corroborated using flow cytometry and confocal imaging studies. It was also manifested that these NO conjugated polymers can physically encapsulate doxorubicin (DOX) in aqueous environment, and the synergistic effect of DOX and NO is reflected in the exhibited cytotoxicity against the MCF-7 (human breast adenocarcinoma) cells. The spatiotemporally modulated NO release steered fluorescence “turn-on” may find abundant biomedical applications.
Download: 0
Show more
Download: 0
Show more
Download: 0
Show more
