Complementary Hydrogen Research Articles

An optimal dispatch strategy of off-grid park integrated energy system considering source volatility

An off-grid integrated energy system (IES) with hydrogen storage at park-level is proposed, utilizing wind, solar and natural gas as the main energy supply to replace fossil fuels, in order to overcome the insufficient consideration of energy source conversion and information exchange in the traditional energy system. Firstly, an IES schematic consisted with typical devices is proposed, and all the components are modelled in detail. Then, based on the renewable energy (RE) input requirements and the facility parameters, an optimal dispatch model for multi-energy conversion based on hydrogen storage has been demonstrated. In addition, an improved particle swarm optimization algorithm is also introduced to improve the strategy. Combined with the environmental characteristics, the multi-objective solution with the lowest economic cost and environmental cost, the highest energy supply reliability and energy efficiency as the optimization objectives is determined. Finally, a case study is conducted using the practical data of the Chongli Large-Scale Wind-Solar Complementary Coupled Hydrogen Production System Application Demonstration Project to validate the feasibility of the study under real conditions. The result shows that the RE consumption rate is greater than 99 % under the premise of considering the environmental cost and ensuring the operation reliability, which can effectively improve the operation economy and user economy of the power grid

Morphological Transformation and Surface Engineering of Glycovesicles Driven by Bioinspired Hydrogen Bonds of Nucleobases.

Glycopolymer-based supramolecular glycoassemblies with signal-driven cascade morphological deformation and accessible surface engineering toward bioinspired functional glycomaterials have attracted much attention due to their diverse applications in fundamental and practical scenarios. Herein, we achieved the cascade morphological transformation and surface engineering of a nucleobase-containing polymeric glycovesicle through exploiting the bioinspired complementary multiple hydrogen bonds of complementary nucleobases. First, the synthesized thymine-containing glycopolymers (PGal30-b-PTAm249) are capable of self-assembling into well-defined glycovesicles. Several kinds of amphiphilic adenine-containing block copolymers with neutral, positive, and negative charges were synthesized to engineer the glycovesicles through the multiple hydrogen bonds between adenine and thymine. A cascade of morphological transformations from vesicles to ruptured vesicles with tails, to worm-like micelles, and finally to spherical micelles were observed via continuously adding the adenine-containing polymer into the thymine-containing glycovesicles. Furthermore, the surface charge properties of these glyconano-objects can be facilely regulated through incorporating various adenine-containing polymers. This work demonstrates the potential application of a unique bioinspired approach to precisely engineer the morphology and surface properties of glycovesicles for boosting their biological applications.

Electrochemical-thermochemical complementary hydrogen production system for efficient full-spectrum solar energy storage

Solar hydrogen production, which can store unstable solar energy into clean hydrogen, has garnered widespread attention from researchers. However, there are some shortcomings in the single solar hydrogen production pathway: Photovoltaic-electrolytic green hydrogen production primarily harnesses short-wavelength solar energy, neglecting a significant portion of solar energy in the long-wavelength, while solar thermochemical methane reforming for gray hydrogen production underutilizes high-grade solar energy and emits carbon dioxide. This study presents a hybrid system capable of concurrently producing green and gray hydrogen, effectively harnessing the entire spectrum of solar energy while minimizing carbon emissions. Thermodynamic investigations reveal that the system attains energy efficiency of 47.43 %, exergy efficiency of 41.93 %, and solar-to-hydrogen efficiency of 25.61 % at the direct normal irradiance (DNI) of 1000 W/m2. It is intriguing to observe the discrepancy in the proportions of energy input from solar energy and methane, along with their respective impacts on hydrogen production. Although solar energy input constitutes 85.26–63.44 % of the total energy input, its contribution to hydrogen production is 64.94 %–33.71 %. Despite the reduced proportion of solar energy's contribution to hydrogen production compared to its input proportion, it significantly contributes to reducing fossil energy usage and carbon emissions. This system's average carbon dioxide reduction rate stands at around 16.84–13.80 kg/kgH2. The proposed system offers an efficient approach to full-spectrum solar energy storage and hydrogen production, thus contributing to a cleaner energy future.

Oxidation behavior of Zr-2.5Nb alloy exposed to steam in the temperature range of 600–1200 °C

Zr-2.5Nb pressure tube material was subjected to isothermal steam exposures in the range 600–1200 °C for different durations to predict its oxidation behavior during hypothetical accident scenarios. The oxidation exponent obtained from power law fitting of the thermogravimetry (TG) curves deviated from parabolic regime. Nevertheless, oxidation kinetics was described by determining the parabolic rate constants (Kp) in two temperature ranges: Kp = 0.029 exp(-111075/RT) (kg/m2)2/sec for 600–900 °C whereas Kp = 77652.6 exp(-254824/RT) (kg/m2)2/sec for 900–1200 °C. In the tested durations, only the 1000 °C sample has shown breakaway transition, after approximately 105 min and has absorbed the highest amount of hydrogen amongst all samples. The trend in hydrogen pickup fraction (HPUF) was verified by two complementary hydrogen determination methods. Clear differences were identified in the α-Zr(O) layer formed on the samples below and above 900 °C. In the α + β range of 600–900 °C, α-Zr(O) consisted of tiny β precipitates. At and above 900 °C in the fully β range, columnar α-Zr(O) grains were observed.

Supramolecular Polymers: Inherently Dynamic Materials.

ConspectusSince its inception in the early 1990s, the field of supramolecular polymers (SPs) has grown into an interdisciplinary field of chemistry. It expanded from the self-assembly of molecular building blocks based on H-bonding into the realm of complex dynamic material, encompassing both supramolecular noncovalent and molecular covalent regimes. It has paved the path for a more diverse field of research into a new class of polymeric materials, coined dynamic polymers or dynamers. Dynamers are bringing a paradigm shift not only in material science research but also in a broad field of applications from self-healing materials to biocompatible polymeric materials. The present Account presents the evolution of supramolecular polymer chemistry from simple linear polymeric chains to complex dynamic polymers imparting novel functional properties, such as component exchange and self-healing. We explore how SPs led to materials of increasing complexity, starting from simple main-chain polymers to the formation of more complex columnar SPs and lateral SPs. The field has experienced three partially overlapping periods. The main goal was first the generation of polymeric entities from various molecular components connected through noncovalent interactions, especially complementary hydrogen bonding recognition patterns as well as stacked columnar SPs. Thereafter, attention was directed in parallel to the exploration of the properties of SPs and their applications as novel materials. In a third period, the dynamic properties of supramolecular polymers were explored, taking advantage of the lability of noncovalent interactions to perform component rearrangement and exchange. We illustrate how the field of SPs has emerged as a multidisciplinary field of chemistry, biology, and materials science with selected examples from the literature. The SPs, specifically dynamic owing to their inherent reversibility, also pave the path to easier sorting and recycling, as desired in the plastics industry.One of the biggest challenges that the plastics industry is facing today is the end-of-life fate of plastics. Plastics that cannot be recycled end up in landfills or are improperly disposed of in rivers and oceans, polluting and damaging the environmental balance irreversibly. Dynamic polymeric materials presenting inherent dynamicity could pave the way for addressing this long-standing challenge of nonrecyclability of plastics. Dynamers formed via noncovalent interactions or reversible covalent bonds can be broken into components that could be easily recycled and reused. Therefore, dynamers could play a pivotal role toward closing the loop for the plastics industry and provide a solution to an elusive circular economy with plastics being an integral part.

Purpose-built multicomponent supramolecular silver(I)-hydrogels as membrane-targeting broad-spectrum antibacterial agents against multidrug-resistant pathogens.

Membrane-targeting compounds are of immense interest to counter complicated multi-drug resistant infections. However, the broad-spectrum effect of such compounds is often unmet due to the surges of antibiotic resistance among majority of Gram-negative bacteria compared to Gram-positive species. Though amphiphiles, synthetic mimics of antimicrobial peptides etc, have been extensively explored for their potential to perturb bacterial membranes, small molecule-based supramolecular hydrogels have remained unexplored. The design of supramolecular hydrogels can be tuned on-demand, catering to desired applications, including facile bacterial membrane perturbation. Considering the strong biocidal properties of Ag-based systems and the bacterial membrane-targeting potential of appended primary amine groups, we designed self-assembled multicomponent supramolecular Ag(I)-hydrogels with urea and DATr (3,5-diamino-1,2,4-triazole) as ligands, which are predisposed for hydrogen bonding and interacting with negatively charged bacterial membranes at physiological pH. The synthesized supramolecular Ag(I)-hydrogels exhibited almost similar antibacterial activity against both Gram-negative (Campylobacter jejuni; C. jejuni) and Gram-positive (Staphylococcus aureus; S. aureus) bacteria, with minimal inhibitory concentration (MIC) of ∼60 μg mL-1. Ag(I)-hydrogels facilitated the disruption of the negatively charged bacterial membrane due to electrostatic interaction and complementary hydrogen bonding facilitated by DATr and urea. Sustained intracellular ROS generation in the presence of Ag(I)-hydrogel further expedited cell lysis. We envisage that the multicomponent supramolecular Ag(I)-hydrogels studied herein can be employed in designing effective antibacterial coatings on a range of medical devices, including surgical instruments. Moreover, the present form of the hydrogels has the potential to improve the antibacterial functionality of conventional antimicrobials, thus revitalizing the effective targeting of hard-to-treat multi-drug-resistant (MDR) bacterial infections in a clinical set up.

Molecular aggregation by hydrogen bonding in cold-crystallization behavior of mixed nucleobases analyzed by temperature-controlled infrared spectroscopy.

The cold-crystallization behaviors of dodecyl-substituted nucleobases (adenine, uracil, and thymine) were analyzed. The dodecyl derivative from uracil alone did not exhibit cold crystallization; however, a mixture of adenine and uracil derivatives at a molar ratio of 1 : 1 exhibited cold crystallization. These results are similar to the thermal behavior of dodecyl derivatives of adenine and thymine alone and in mixtures reported in a previous study. Temperature-controlled infrared spectroscopy was used to observe the molecular assembly states of the liquid, supercooled state, and cold-crystallized compounds. Hydrogen-bonded molecular pairs in the high-temperature liquid state, multiple hydrogen-bonded networks in the supercooled state, and reverse Hoogsteen-type complementary hydrogen bonds in cold-crystallized compounds were observed using infrared spectroscopy. The heterogeneity of the system, due to multiple types of hydrogen bonding, retarded the crystallization rate, resulting in supercooling and cold crystallization. Infrared spectroscopy, which can be used to measure the aggregation state of molecules, including the liquid and supercooled states, is an effective analytical method for clarifying the process of cold crystallization.

Duplex-forming oligocarbamates with tunable nonbonding sites.

In biopolymers such as proteins and nucleic acids, monomer sequence encodes for highly specific intra- and intermolecular interactions that direct self-assembly into complex architectures with high fidelity. This remarkable structural control translates into precise control over the properties of the biopolymer. Polymer scientists have sought to achieve similarly precise control over the structure and function of synthetic assemblies. A common strategy for achieving this goal has been to exploit existing biopolymers, known to associate with specific geometries and stoichiometries, for the assembly of synthetic building blocks. However, such systems are neither scalable nor amenable to the relatively harsh conditions required by various materials science applications, particularly those involving non-aqueous environments. To overcome these limitations, we have synthesized sequence-defined oligocarbamates (SeDOCs) that assemble into duplexes through complementary hydrogen bonds between thymine (T) and diaminotriazine (D) pendant groups. The SeDOC platform makes it simple to incorporate non-hydrogen-bonding sites into an oligomer's array of recognition motifs, thereby enabling an investigation into this unexplored handle for controlling the hybridization of complementary ligands. We successfully synthesized monovalent, divalent, and trivalent SeDOCs and characterized their self-assembly via diffusion ordered spectroscopy, 1H-NMR titration, and isothermal titration calorimetry. Our findings reveal that the binding strength of monovalent oligomers with complementary pendant groups is entropically driven and independent of monomer sequence. The results further show that the hybridization of multivalent oligomers is cooperative, that their binding enthalpy (ΔH) and entropy (TΔS) depend on monomer sequence, and that sequence-dependent changes in ΔH and TΔS occur in tandem to minimize the overall change in binding free energy.

Self-Healing Hydrogen-Bonded Organic Frameworks for Low-Concentration Ammonia Capture.

The self-healing behavior has been extensively used in intelligent sensing systems capable of molecular recognition. However, most rigid crystalline frameworks, once collapsed under external stimuli like pressure, heat, or vacuum, could hardly recover to their crystalline phases under ambient conditions. Here, we report the self-healing of a new microporous hydrogen-bonded organic framework, FDU-HOF-3 (FDU = Fudan University), for ammonia (NH3) capture and compared it with the established mesoporous HOF-101. With the introduction of low-concentration NH3 into the pores, the HOFs became disordered but were then simply heated under a vacuum to return to their original crystalline states after NH3 removal. Close characterizations revealed that the repeatable self-healing behavior of these HOFs was achieved due to the COOH-NH3 acid-base interactions accompanied by the breaking and regeneration of complementary COOH-COOH hydrogen bonds. FDU-HOF-3 showed a record-capturing capability for low-concentration NH3 (8.13 mmol/g at 25 mbar) among all HOFs and displayed a quick photocurrent decrease after exposure to 250 ppm NH3 for less than 10 s. These self-healing HOFs were used to capture and release NH3 for over 10 cycles without any decrease in the adsorption capacities.

Structure-Controllable and Mass-Produced Glycopolymersomes as a Template of the Carbohydrate@Ag Nanobiohybrid with Inherent Antibacteria and Biofilm Eradication.

Glycopolymer-supported silver nanoparticles (AgNPs) have demonstrated a promising alternative to antibiotics for the treatment of multidrug-resistant bacteria-infected diseases. In this contribution, we report a class of biohybrid glycopolymersome-supported AgNPs, which are capable of effectively killing multidrug-resistant bacteria and disrupting related biofilms. First of all, glycopolymersomes with controllable structures were massively fabricated through reversible addition-fragmentation chain transfer (RAFT) polymerization-induced self-assembly (PISA) in an aqueous solution driven by complementary hydrogen bonding interaction between the pyridine and amide groups of N-(2-methylpyridine)-acrylamide (MPA) monomers. Subsequently, Ag+ captured by glycopolymersomes through the coordination between pyridine-N and Ag+ was reduced into AgNPs stabilized by glycopolymersomes upon addition of the NaBH4 reducing agent, leading to the formation of the glycopolymersome@AgNPs biohybrid. As a result, they showed a wide-spectrum and enhanced removal of multidrug-resistant bacteria and biofilms compared to naked AgNPs due to the easier adhesion onto the bacterial surface and diffusion into biofilms through the specific protein-carbohydrate recognition. Moreover, the in vivo results revealed that the obtained biohybrid glycopolymersomes not only demonstrated an effective treatment for inhibiting the cariogenic bacteria but also were able to repair the demineralization of caries via accumulating Ca2+ through the recognition between carbohydrates and Ca2+. Furthermore, glycopolymersomes@AgNPs showed quite low in vitro hemolysis and cytotoxicity and almost negligible acute toxicity in vivo. Overall, this type of biohybrid glycopolymersome@AgNPs nanomaterial provides a new avenue for enhanced antibacterial and antibiofilm activities and the effective treatment of oral microbial-infected diseases.

A Solution‐Processable Porphyrin‐Based Hydrogen‐Bonded Organic Framework for Photoelectrochemical Sensing of Carbon Dioxide

AbstractDetecting CO2 in complex gas mixtures is challenging due to the presence of competitive gases in the ambient atmosphere. Photoelectrochemical (PEC) techniques offer a solution, but material selection and specificity remain limiting. Here, we constructed a hydrogen‐bonded organic framework material based on a porphyrin tecton decorated with diaminotriazine (DAT) moieties. The DAT moieties on the porphyrin molecules not only facilitate the formation of complementary hydrogen bonds between the tectons but also function as recognition sites in the resulting porous HOF materials for the selective adsorption of CO2. In addition, the in‐plane growth of FDU‐HOF‐2 into anisotropic molecular sheets with large areas of up to 23000 μm2 and controllable thickness between 0.298 and 2.407 μm were realized in yields of over 89 % by a simple solution‐processing method. The FDU‐HOF‐2 can be directly grown and deposited onto different substrates including silica, carbon, and metal oxides by self‐assembly in situ in formic acid. As a proof of concept, a screen‐printing electrode deposited with FDU‐HOF‐2 was fabricate as a label‐free photoelectrochemical (PEC) sensor for CO2 detection. Such a signal‐off PEC sensor exhibits low detection limit for CO2 (2.3 ppm), reusability (at least 30 cycles), and long‐term working stability (at least 30 days).

A Solution-Processable Porphyrin-Based Hydrogen-Bonded Organic Framework for Photoelectrochemical Sensing of Carbon Dioxide.

Detecting CO2 in complex gas mixtures is challenging due to the presence of competitive gases in the ambient atmosphere. Photoelectrochemical (PEC) techniques offer a solution, but material selection and specificity remain limiting. Here, we constructed a hydrogen-bonded organic framework material based on a porphyrin tecton decorated with diaminotriazine (DAT) moieties. The DAT moieties on the porphyrin molecules not only facilitate the formation of complementary hydrogen bonds between the tectons but also function as recognition sites in the resulting porous HOF materials for the selective adsorption of CO2 . In addition, the in-plane growth of FDU-HOF-2 into anisotropic molecular sheets with large areas of up to 23000 μm2 and controllable thickness between 0.298 and 2.407 μm were realized in yields of over 89 % by a simple solution-processing method. The FDU-HOF-2 can be directly grown and deposited onto different substrates including silica, carbon, and metal oxides by self-assembly in situ in formic acid. As a proof of concept, a screen-printing electrode deposited with FDU-HOF-2 was fabricate as a label-free photoelectrochemical (PEC) sensor for CO2 detection. Such a signal-off PEC sensor exhibits low detection limit for CO2 (2.3 ppm), reusability (at least 30 cycles), and long-term working stability (at least 30 days).

One‐Step Synthesis of Hydrogen‐Bonded Microcapsules for pH‐Triggered Protein Release

One‐step microfluidic approach in which interfacial complexation of hydrogen bonding polymers is utilized to prepare pH‐responsive microcapsules is presented. Using water‐in‐oil‐in‐oil‐in‐water (W1/O1/O2/W2) triple‐emulsion droplets as templates, it is shown that polymeric microcapsules with an aqueous core and a shell that consists of two complementary hydrogen bonding polymers, poly(propylene oxide)(PPO) and poly(methacrylic acid)(PMAA), can be prepared in a robust manner. The presence of a buffer layer enables controlled interfacial complexation of PMAA and PPO at the water/oil interface, followed by spontaneous dewetting of the oil droplet to result in hydrogen‐bonded microcapsules dispersed in aqueous media. In addition, it is demonstrated that the permeability of the PPO/PMAA membrane can be readily tuned by varying the molecular weight of PMAA. Furthermore, it is shown that the resulting PPO/PMAA microcapsules are stable at a high salt concentration (>1 m NaCl) unlike analogous capsules prepared through electrostatic complexation while they release the encapsulated protein above the critical pH of which the PMAA ionizes and results in disassembly of the shell membrane.

Supramolecular cocrystals of dispiro-P3N3-dicarboxylic acid: Synthesis, structural characterization and hirshfeld surface analysis

The design of cocrystals for a particular molecule begins with examining that molecule's functional group and selecting a complementary functional group that would generate the foreseeable supramolecular synthons. In this work, the cyclotriphosphazene-based compound Dispiro-P3N3-dicarboxylic acid (L) was identified to produce two cocrystals with two different N-donor compounds such as 4,4′-bipyridine and piperazine by slow evaporation technique. These compounds 1 and 2 were characterized by single-crystal X-ray diffraction, PXRD, FT-IR, NMR, UV–Vis spectroscopy, TG analysis, computational analysis of pKa and Hirshfeld surface analysis. The ΔpKa value of compounds 1 (-0.180) and 2 (0.191) indicates that both are cocrystals in nature. Compounds 1 and 2 have the same triclinic crystal system with space group Pī. X-ray diffraction analysis displays that both compounds were formed with the coformer through complementary hydrogen bonding with an alternating sequence of Dispiro-P3N3-dicarboxylic acid and N-donor compounds. Compound 1 exhibits O-H···N and C-H···O hydrogen bonding interactions between Dispiro-P3N3-dicarboxylic acid and 4,4′-bipyridine that results in the formation of one-dimensional polymeric chains A and B. In addition, the adjacent one-dimensional polymeric chains A and B in compound 1 are further held together by π···π interactions between phenyl groups of Dispiro-P3N3-dicarboxylic acids from two different set of one-dimensional polymeric chains A and B. In compound 2, the recognition between Dispiro-P3N3-dicarboxylic acid and piperazine is established via O-H···N, N-H···O hydrogen bondings and π···π interactions which leads to the formation of one-dimensional polymeric chains. Furthermore, the one-dimensional polymeric chains are interconnected with each other via C-H···N hydrogen bondings which results to the formation of two-dimensional sheet like structure in compound 2. Hirshfeld surface analysis confirmed that the O-H···N hydrogen bondings are major interactions in compound 1; in contrast, N-H···O hydrogen bondings are more prominent interactions than the O-H···N hydrogen bondings in compound 2.

Abstract 3840: High-resolution structural insights into targeting the MYC oncogene G-quadruplex with the quinoline derivative PEQ

Abstract The transcription of the MYC oncogene, a central player of oncogenesis, is strongly controlled by DNA G-quadruplexes in its promoter region (MycG4). Stabilization of MycG4 with small molecules downregulates MYC expression and has devastating effects on many cancers. Thus, targeting MycG4 is an attractive anti-cancer strategy especially since the MYC protein is considered a very difficult target. DNA G-quadruplexes are four-stranded secondary structures and enriched in promoters of oncogenes. Their globular shape and high structural diversity distinguishes them from the thread-like and uniform DNA duplex ubiquitously found in the cell. High-resolution structures reveal the molecular interactions between ligands and G-quadruplexes and are the key for structure-based rational design of new and improved drugs. Here, we present the new MycG4 binder PEQ, a quinoline derivative, and describe its molecular recognition of the MycG4. PEQ is more drug-like than many prominent G-quadruplex binder because it lacks an extensive aromatic moiety. Most of the reported G-quadruplex binding ligands include extended and rigid aromatic moieties with less drug-like properties. We used solution NMR and molecular dynamics calculations to first determine the high-resolution structures of the unbound wild-type MycG4, and next structures of PEQ in complex to wild-type MycG4 or the most commonly studied modified MycG4. This modified MycG4 sequence bears a mutated residue in the binding pocket that is critical for ligand interactions. PEQ binds the MycG4 with a 2:1 stoichiometry and stacks on the G-quadruplex ends. Specific binding pockets are formed in which a flanking residue is recruited by the PEQ to form a joint-plane. The identity of the recruited residue controls the orientation of the ligand and the resulting interactions, as shown by structural comparison of PEQ in complex with either the wild-type or mutated MycG4. Including the PEQ structure, four ligand-MycG4 complexes are now available and we performed the first systematic analysis. We show that despite the dynamic character of the flanking sequences, all ligands recruit DNA bases in a conserved and sequence-specific manner. Moreover, we propose the design of complementary hydrogen bonds to match the recruited DNA base with a drug via structure-based rational design. In conclusion, our work introduces the quinoline PEQ as new lead compound for cancer therapeutics targeting MYC through the MycG4. We present the MycG4-ligand structure with wild-type binding sites as more accurate target and identify important aspects of ligand binding to guide future design of cancer therapeutics. Citation Format: Jonathan Dickerhoff, Jixun Dai, Danzhou Yang. High-resolution structural insights into targeting the MYC oncogene G-quadruplex with the quinoline derivative PEQ. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3840.

Self-Assembled Supramolecular Micelles Based on Multiple Hydrogen Bonding Motifs for the Encapsulation and Release of Fullerene.

Living creatures involve several defense mechanisms, such as protecting enzymes to protect organs and cells from the invasion of free radicals. Developing antioxidant molecules and delivery systems to working with enzymes is vital. In this study, a supramolecular polymer PNI-U-DPy was used to encapsulate C60, a well-known antioxidant that is hard to dissolve or disperse in the aqueous media. PNI-U-DPy exhibits characteristics similar to PNIPAM but could form micelles even when the environment temperature is lower than its LCST. The U-DPy moieties could utilize their strong complementary hydrogen bonding-interaction to create a physically crosslinked network within PNIPAM micelles, thus adjusting its LCST to a value near the physiological temperature. Morphological studies suggested that C60 could be effectively loaded into PNI-U-DPy micelles with a high loading capacity (29.12%), and the resulting complex PNI-C60 is stable and remains temperature responsive. A series of measurements under variable temperatures was carried out and showed that a controlled release process proceeded. Furthermore, PNI-C60 exhibits hydroxyl radicals scavenging abilities at a low dosage and could even be adjusted by temperature. It can be admitted that the micelle system can be a valuable alternative for radical scavengers and may be delivered to the desired position with good dispersibility and thermo-responsivity. It is beneficial to the search progress of scientists for drug delivery systems for chemotherapeutic treatments and biomedical applications.

Quantification of Exchanged Copper Species in Cu‐Chabazite Zeolite using Cryogenic Probe Infrared Spectroscopy

AbstractThe development of a low temperature (−160 °C) NO adsorption technique is disclosed that avoids the chemical conversion of the probe molecule at room temperature. The observed IR peaks for Cu+(NO)2 and Cu2+(NO) species can be used to quantify the amount of exchanged copper species in a broad range of samples, including a wash‐coated honeycomb. Calibration curves for Cu+(NO)2 and Cu2+(NO) are determined for copper loadings up to 3.99 wt% with Silica‐to‐Alumina Ratio (SAR) of 16–22, and quantitative agreement with the complementary hydrogen Temperature Programmed Reduction (H2‐TPR) results is established. This methodology allows to identify different Cu species in Cu‐CHA, such as Z2Cu(II), Z1Cu(II)OH and Cu dimers, based on their distinct IR signatures. In addition, the perturbed T−O−T framework vibration – characterized at 400 °C – can also be used as a complimentary method to quantify Z2Cu(II) species.

Chiroptical coassemblies between organic carboxylic acids and amino acid derivatives with C3-symmetry

Benzimidazole amino acid derivatives behave as supramolecular hosts to include organic acids via complementary hydrogen bonding whereby supramolecular chirality and chiroptical properties could be manipulated. Organic acids enhanced the chiral assembly that showed tunable circularly polarized luminescence with high dissymmetry g-factors at 10−2 grade.

Supramolecular hierarchical polyurethane elastomers for thermal and mechanical property optimization

Supramolecular chemical designs that integrate complementary hydrogen bond donor and acceptor complexes in hierarchical polyurethane elastomers are reported. N2,N6-bis(2-hydroxyethyl)pyridine-2,6-dicarboxamide (PDA) and 5,5-bis(3-hydroxypropyl)barbituric acid (BBA) react with 4,4′-methylenediphenyl diisocyanate (MDI) to produce hard segments capable of multiple intermolecular hydrogen bonds in MDI-PDA/BBA-poly(tetramethylene oxide) (PTMO) polyurethanes. The addition of PDA facilitates the formation of a supramolecular complex, and BBA affords greater intersegmental mixing. As a result, these polyurethanes exhibit higher glass transition temperatures (Tg) and greater strain hardening/strengthening under tensile deformation than a microphase-separated MDI-butanediol (BDO)-PTMO analog. Additionally, increased PDA and BBA contents results in up to a 60 °C increase of Tg determined at 1 Hz via DMA relative to those determined by calorimetric measurements via DSC, which is considerably higher than the 15 °C Tg increase observed in the MDI-BDO-PTMO analog. These results highlight a significant interplay between intersegmental mixing and supramolecular hydrogen bond interactions for the design of robust hierarchical elastomers.

Role of a secondary building unit of copper 2,3-Pyridinedicarboxylate coordination polymer in the interactions with ionic dyes

• A secondary building unit of a copper(II) 2,3-pyridinedicarboxylate stabilized by with amino-methylthiazolium cation was structurally characterized. • The interactions of the SBU and the corresponding coordination polymer with cationic and anionic dyes were investigated. • The in-situ change in pH by cation exchange during dye interaction caused oscillation in the concentration of a dye with time. A secondary building unit (SBU) and the corresponding copper 2,3-pyridinedicarboxylate coordination polymer of it were investigated to unfold the comparative ability on the interactions with ionic dyes. Complementary hydrogen bonds of the 2-amino-4-methylthiazolium cation enabled us to stabilise the SBU by organo-cations. The SBU was characterised by IR, UV–visible, thermogravimetry, ESR, PXRD and finally by determining the crystal structure. The interactions of the SBU and the coordination polymer with organic ionic dyes, namely, methyl-violet 2B, methyl-orange and rhodamine B had shown oscillation concentration of the adsorbed dye. The comparative study revealed that irrespective of the ionic nature of the dye, similar interactions by the coordination polymer with the SBU were observed where the pH change caused by ion exchange guided the adsorption at a particular time.