Transparent Solution Research Articles

Preparation and properties of light-triggered self-healing form-stable phase change materials

Light-triggered self-healing form-stable phase change materials (FSPCMs) can not only store and release thermal energy, but can also realize self-healing performance under light, showing important practical values. In this article, we provided a new strategy for the preparation of FSPCMs with light-triggered self-healing ability and high thermal energy storage density. Azobenzene side chain liquid crystal polymer was synthesized and used as gelator to blend with paraffin, and then the mixture was heated and dissolved to form transparent solutions. FSPCMs could be obtained after natural cooling to room temperature. The thermal stability, energy storage capacity and rheological property of the prepared FSPCMs were studied in detail. With the increase of gelator content, the thermal stability and storage modulus of FSPCMs enhanced, while the energy storage density decreased. When the gelator content is 6.0 wt%, the gel-sol phase transition temperature (TGS) of the FSPCM was 127 °C, the storage modulus could achieve 2.3 × 103 Pa at 70 °C, and the phase change enthalpy was 193.1 J g−1, showing excellent self-supporting performance and higher energy storage density. More interestingly, the FSPCMs also showed excellent light-triggered self-healing ability. When the FSPCMs were damaged, the materials could quickly repair the damage under the sequential irradiation of 365 nm and 470 nm light.

Biodegradable Interpolycomplexes for Anti-Erosion Stabilization of Soil and Sand.

A linear anionic polysaccharide, sodium alginate, electrostatically interacts with a cationic polysaccharide, quaternized hydroxyethyl cellulose ethoxylate, in aqueous solution, thus giving an interpolyelectrolyte complex. Aqueous solutions of the initial polysaccharides and polycomplexes with an excess of the cationic or anionic polymers were used for the stabilization of soil and sand against water erosion. Physicochemical, mechanical and biological properties of the polymers and coatings were characterized by gravimetric analysis, viscosimetry, mechanical strength assessment, cell viability, and cell-mediated degradation with the following main conclusions. (a) Non-stoichiometric polycomplexes with an excess of cationic or anionic units ("cationic" and "anionic" polycomplexes, respectively) form transparent solutions or stable-in-time dispersions. (b) The complexation results in a decrease in the viscosity of polymer solutions. (c) A complete dissociation of polycomplexes to the initial components is achieved in a 0.2 M NaCl solution. (d) Soil/sand treatment with 1 wt% aqueous solutions of polymers or polycomplexes and further drying lead to the formation of strong composite coatings from polymer(s) and soil/sand particles. (e) Cationic polycomplexes form stronger coatings in comparison with anionic polycomplexes. (f) The polymer-soil coatings are stable towards re-watering, while the polymer-sand coatings show a much lower resistance to water. (g) The individual polysaccharides demonstrate a negligible toxicity to Gram-negative and Gram-positive bacteria and yeast. (h) The addition of Bacillus subtilis culture initiates the degradation of the polysaccharides and polycomplexes. (i) Films from polysaccharides and polycomplexes decompose down to small fragments after being in soil for 6 weeks. The results of the work are of importance for constructing water-resistant, low toxicity and biodegradable protective coatings for soil and sand.

A Comparative Study of Cellulose Ethers as Thermotropic Materials for Self-Tracking Solar Concentrators

The continuous growth in energy demand requires researchers to find new solutions to enlarge and diversify the possible ways of exploiting renewable energy sources. Our idea is the development of a solar concentrator based on trapping the luminous radiation with a smart window. This system is able to direct light towards the photovoltaic cells placed on window borders and produce electricity, without any movable part and without changing its transparency. Herein, we report a detailed study of cellulose ethers, a class of materials of natural origin capable of changing their state, from transparent aqueous solution to scattering hydrogel, in response to a temperature change. Cellulose thermotropism can be used to produce a scattering spot in a window filled with the thermotropic fluid to create a new kind of self-tracking solar concentrator. We demonstrate that the properties of the thermotropic fluid can be finely tuned by selecting the cellulose functionalization, the co-dissolved salt, and by regulating their dosage. Lastly, the results of our investigation are tested in a proof-of-concept demonstration of solar concentration achieved by thermotropism-based light trapping.

Blockchain Technology Implementation in the Energy Sector: Comprehensive Literature Review and Mapping

Satisfying the world’s rapidly increasing demands in energy via the optimized management of available resources is becoming one of the most important research trends worldwide. When it comes to energy, it is very important to talk about decentralization, security, traceability and transparency. Thus, over the last few years, numerous research works have presented blockchain technology as the best novel business platform enabling a secure, transparent and tamper-proof energy management solution. In this paper, we conducted a systematic literature review (SLR) using the PRISMA framework of the different existing research studies related to the use of the blockchain technology in the energy sector, published between 2008 and 2021. We identified a total of 769 primary studies after intensive manual analysis and filtering, which we thoroughly assessed using various criteria to address six main research questions that covered the blockchain types, applications and platforms in the energy sector, the energy source types for which blockchain platforms are implemented, the emergent technologies that are combined to blockchain solutions, and the types of consensuses used in energy blockchains. Based on the collected survey data, we built a database to categorize the existing research works, identify research trends, and highlight knowledge gaps and potential areas for additional field study.

Detection of Mental Fatigue in the General Population: Feasibility Study of Keystroke Dynamics as a Real-world Biomarker

Background Mental fatigue is a common and potentially debilitating state that can affect individuals’ health and quality of life. In some cases, its manifestation can precede or mask early signs of other serious mental or physiological conditions. Detecting and assessing mental fatigue can be challenging nowadays as it relies on self-evaluation and rating questionnaires, which are highly influenced by subjective bias. Introducing more objective, quantitative, and sensitive methods to characterize mental fatigue could be critical to improve its management and the understanding of its connection to other clinical conditions. Objective This paper aimed to study the feasibility of using keystroke biometrics for mental fatigue detection during natural typing. As typing involves multiple motor and cognitive processes that are affected by mental fatigue, our hypothesis was that the information captured in keystroke dynamics can offer an interesting mean to characterize users’ mental fatigue in a real-world setting. Methods We apply domain transformation techniques to adapt and transform TypeNet, a state-of-the-art deep neural network, originally intended for user authentication, to generate a network optimized for the fatigue detection task. All experiments were conducted using 3 keystroke databases that comprise different contexts and data collection protocols. Results Our preliminary results showed area under the curve performances ranging between 72.2% and 80% for fatigue versus rested sample classification, which is aligned with previously published models on daily alertness and circadian cycles. This demonstrates the potential of our proposed system to characterize mental fatigue fluctuations via natural typing patterns. Finally, we studied the performance of an active detection approach that leverages the continuous nature of keystroke biometric patterns for the assessment of users’ fatigue in real time. Conclusions Our results suggest that the psychomotor patterns that characterize mental fatigue manifest during natural typing, which can be quantified via automated analysis of users’ daily interaction with their device. These findings represent a step towards the development of a more objective, accessible, and transparent solution to monitor mental fatigue in a real-world environment.

LA METAPHORE TERMINOLOGIQUE ET SA TRADUCTION. LE CAS DE LA TERMINOLOGIE ASTRONOMIQUE FRANÇAISE ET TCHEQUE

In specialized language, the reader encounters metaphors that cover an actualisation and explanatory role. They help to clarify some complex concepts and make them accessible for the reader. Metaphor is also a powerful source of terms and terms of metaphorical origin are abundant in specialized language. Finally, it is possible to examine the translation of metaphors in the specialized language, particularly in relation to the formation of new terms in various fields. The article analyses the translation of metaphors based on a comparison of French and Czech terms, particularly from the field of astronomy, also taking into account terms from other disciplines. Attention is mainly focused on the translation strategies used in the formation of new terms and on the comparison of their use in both languages. Calques and loanwords seem to be the most frequent translation strategies when forming French and Czech terminological equivalents of metaphorical terms in the field of astronomy. The calque is a universal and transparent solution allowing to create parallel metaphorical series in different languages. As for loanwords, the presence of anglicisms in French astronomy terminology is not really massive, probably as a result of the role of French standardizing authorities in the formation of terminological neologisms.

Multi-band transparent optical network planning strategies for 6G-ready European networks

As long-haul network operators upgrade core optical networks to support 5G services, research and standardization efforts for 6G have begun. Keeping in mind the ever-growing demand for high-bandwidth services, our work proposes a novel core-network traffic model which exploits the network’s graph and population metric to estimate demands. We further develop a multi-period Routing, Configuration, and Spectrum Assignment (RCSA) algorithm which takes as input the traffic model demands, and provides network metrics spread across all planning periods.A multi-period multi-band transparent optical network planning study on three European networks is undertaken, using two deployment approaches; namely, flexible bandwidth variable transceivers (Flex-BVTs) and transparent IP over wavelength division multiplexing (IPoWDM). We show that Flex-BVT places up to 15% lesser equipment into the network while carrying up to 20% higher traffic. Using a simple Capital Expenditure (CAPEX) calculation, we also show that the CAPEX-per-bit of deploying Flex-BVTs is up to 12% lower, as compared to transparent IPoWDM solutions.

Study on formulation and preparation technology of the composite cellulose-based enteric capsule shells

Objective To study the new formulation and technology of composite cellulose-based enteric capsule shell with one-time dipping molding without organic solvent. Methods Hydroxypropyl methylcellulose phthalate-55S (Hp55S) was used as the main film-forming material, agar as gelling agent, and hydroxypropyl methylcellulose (HPMC) as disintegrating regulator. The preparation technology was as follows: ① Hp55S was dissolved in dilute ammonia solution with pH of 10 ∼ 11 at room temperature to obtain transparent Hp55S solution. ② The mixture of HPMC, KCl, and Tween-80 was fully dispersed in the agar solution at 90 ∼ 100 °C and cooled to 50 ∼ 55 °C under continuous stirring to obtain a transparent agar/HPMC solution. ③The Hp55S solution was heated to 50 ∼ 55 °C and poured into the agar/HPMC solution and stirred evenly to obtain the composite cellulose solution, which was kept at 50 ∼ 55 °C for standby. ④The composite cellulose-based enteric capsule shells were prepared by dipping, spinning, drying, stripping and trimming, and joining. Results The composite cellulose-based enteric capsule shell prepared according to this formula and process met the quality requirements of ‘enterosoluble vacant capsules’ in Chinese Pharmacopeia. Conclusion Compared with the traditional formula and preparation technology of enteric capsule shell, the product is a plant type enteric capsule shell, no organic solvent is used in the formula, and the forming steps of multiple dipping solution is not used in the process. The advantages of this study are that the production steps are simplified, the production process is environmentally friendly, and the production cost is reduced.

Effective or predatory funding? Evaluating the hidden costs of grant applications.

Researchers are spending an increasing fraction of their time on applying for funding; however, the current funding system has considerable deficiencies in reliably evaluating the merit of research proposals, despite extensive efforts on the sides of applicants, grant reviewers and decision committees. For some funding schemes, the systemic costs of the application process as a whole can even outweigh the granted resources-a phenomenon that could be considered as predatory funding. We present five recommendations to remedy this unsatisfactory situation.

Analysis and Evaluation of Thermal-cooling Loads of Office Buildings Using Carrier Software in Iran

The importance and necessity of energy saving in the world have been discussed for many years, but achieving a logical and transparent solution isstill one of the main challenges and problems of the world’s economy. Therapid growth of energy consumption in the last two decades has caused thesecurity of the domestic energy supply of buildings to face serious problems. In this research, first by entering parameters such as the type of materials, doors and windows, and the type of soil on the floor connected to theground, etc. in the heat and cold load calculation software (HAP Carrier) asthe design calculations and then in the second step entering the specifications inferred from the Iran’s national building code as a reference for energy saving calculations, calculations are performed and compared as the firstcriterion, and finally these two outputs are compared. The actual energyconsumption and determination of the building energy consumption indexare determined as another criterion, as well as the degree of deviation fromthe actual consumption. The results showed that the theoretical method andthe thermal and refrigeration load calculations of the Zanjan Gas Companybuilding have 6% difference in cooling load but the heating load is about34% different, which means for cooling loads, the theoretical model can beused with high accuracy but for heating loads, the national building codeneeds fundamental changes.

Analysis and Evaluation of Thermal-cooling Loads of Office Buildings Using Carrier Software in Iran

The importance and necessity of energy saving in the world have been discussed for many years, but achieving a logical and transparent solution isstill one of the main challenges and problems of the world’s economy. Therapid growth of energy consumption in the last two decades has caused thesecurity of the domestic energy supply of buildings to face serious problems. In this research, first by entering parameters such as the type of materials, doors and windows, and the type of soil on the floor connected to theground, etc. in the heat and cold load calculation software (HAP Carrier) asthe design calculations and then in the second step entering the specifications inferred from the Iran’s national building code as a reference for energy saving calculations, calculations are performed and compared as the firstcriterion, and finally these two outputs are compared. The actual energyconsumption and determination of the building energy consumption indexare determined as another criterion, as well as the degree of deviation fromthe actual consumption. The results showed that the theoretical method andthe thermal and refrigeration load calculations of the Zanjan Gas Companybuilding have 6% difference in cooling load but the heating load is about34% different, which means for cooling loads, the theoretical model can beused with high accuracy but for heating loads, the national building codeneeds fundamental changes.

Physically Cross-Linked Cryogels of Linear Polyethyleneimine: Influence of Cooling Temperature and Solvent Composition

Physically cross-linked cryogels can be prepared using linear polyethyleneimine (L-PEI) and a freeze-thawing technique. L-PEI was synthesized by hydrolysis of poly(2-ethyl-2-oxazoline) under acidic conditions. Dissolution of L-PEI in deionized water was achieved at 80 °C and resulted in a transparent solution, leading to the formation of an opaque gel upon freezing and subsequent thawing. The cryogels exhibited reversibility, and after heating at 80 °C, they formed a clear solution due to the melting of the crystalline domains of L-PEI. The effects of different cooling temperatures and the use of various solvent compositions on L-PEI gelation were also studied. L-PEI cryogels were prepared by freezing aqueous solutions to various temperatures (−196, −80, −30, and 0 °C) for 3 h and subsequent thawing at 25 °C for 24 h. Gel rigidity correlated with the freezing temperature and was strongest when cooled down to −196 °C, consistent with determinations of the degree of crystallinity in the gels, the enthalpy of fusion, and rheological behavior. The effect of solvent mixtures on the crystallinity and rheological properties of L-PEI cryogels was also investigated. Water/ethanol mixtures containing a higher proportion of ethanol significantly reduced the strength, viscosity, and degree of crystallinity of the L-PEI cryogels. Thus, by controlling the freezing temperature or modifying the solvent, L-PEI cryogels can be designed with desired mechanical properties for applications ranging from cell immobilization and tissue culture scaffolds to drug delivery systems or antimicrobial wound dressings.

DEVELOPMENT OF INJECTABLE DOSAGE FORM OF PHYTODRUG ON THE BASIS OF HELLELLOW, YARROW, AND NETTLE FOR THE PREVENTION AND TREATMENT OF POSTPARTUM DISEASES IN COWS

This paper discusses the prospect of developing an injectable form of herbal medicine as a uterotonic, antimicrobial, ruminatory, anti-inflammatory, hemostatic and immunostimulating agent, which includes alcohol tinctures of nettle, yarrow and hellebore, as well as propylene glycol. The methods of pharmaceutical analysis of medicinal plant raw materials, physicochemical and empirical methods were used to determine the optimal composition of the phytocomposition in the following ratio of components per 100 ml: hellebore tincture - 2.5 ml, yarrow tincture - 15.0 ml, nettle tincture - 15, 0 ml, propylene glycol - 67.5 ml. Phytopreparation is a transparent alcohol solution, dark green in color, without foreign impurities and sediment, with a specific smell, soluble in water and alcohol. The results of the safety assessment of the phytopreparation, carried out on laboratory animals, indicate its low toxicity in the enteral and parenteral routes of administration. In pilot studies conducted on cows with signs of acute catarrhal endometritis, which were injected intravenously with the test composition of the phytopreparation at a dose of 30 ml per head, positive results were obtained. 10-15 minutes after the intravenous administration of the phytopreparation in cows, a contraction of the muscles of the uterus and the release of exudate were recorded. The results of early gynecological medical examination of cows, carried out 14 days after calving, confirm the high therapeutic efficacy of the developed composition in acute purulent-catarrhal endometritis and subinvolution of the uterus in cows.

Robust and Highly Transparent Photocurable Fluorinated Polyurethane Coating Prepared via Thiol-Click Reactions and What Essentially Influences Omniphobic Coating’s Anti-Graffiti Properties

Without a fragile micro/nanostructure, omniphobic coatings have a natural advantage over superomniphobic coatings in mechanical durability, especially when confronted with finger wipes and squeezes in practical use. Many reported omniphobic coatings with lower liquid sliding angles showed better ink trace resistance. However, according to our results, these two properties are not positively related. The respective critical factors for lowering the liquid sliding angle and resisting tiny contaminants, such as ink stroke and fingerprint, remain elusive. Through three steps of the thiol-click reaction, a surface-dried, highly transparent, mechanically and chemically robust, fluorinated polyurethane coating was photocured efficiently. Surfaces that exhibited better sliding performance but worse resistance to ink stroke and fingerprint were reported. Our results indicate that a heavy cross-linked structure was beneficial for the resistance to tiny contaminants, while the liquid sliding performance only depended on the surface fluorine content, especially the surface enrichment of flexible low-surface-tension chains. Interestingly, an unexpected transformation from a turbid dispersion to a transparent solution during the preparation was observed. The efficient thiol-click reaction induces a micelle-like structure to open and imparts high transparency to the final coatings. Therefore, this work provides useful information to facilitate the study of omniphobic coatings, as well as a good candidate in anti-graffiti applications.

Annealing free CeO2 electron transport layer for efficient perovskite solar cells

Electron transport material plays a critical role in perovskite solar cells. The most commonly used electron transport material, TiO2, has to be sintered at high temperature to achieve good crystallinity and high carrier mobility, complicating the preparation procedure and limiting the development of flexible devices. In this work, we firstly propose a kind of stoichiometric CeO2 film as annealing free electron transport layer for efficient perovskite solar cells. The CeO2 nanocrystals are prepared by solvothermal method. The obtained CeO2 nanocrystals can be well re-dispersed in cyclohexane to form a stable, homogeneous and transparent solution. As a result, we can prepare the CeO2 electron transport layer by spin-coating method and without any annealing or drying process. The performance of the CeO2 electron transport layer is regulated by optimizing the solvothermal reaction time. It is found that the CeO2 nanocrystals prepared under 48 ​h display the most excellent electron extraction performance. The corresponding device acquires a power conversion efficiency of 13.69%. The efficiency is further improved to 16.53% after introducing C60 interlayer. The work presents that CeO2 can be an efficient low temperature processed electron transport material for perovskite solar cells.

TransformEHRs: a flexible methodology for building transparent ETL processes for EHR reuse.

During the COVID-19 pandemic, several methodologies were designed for obtaining electronic health record (EHR)-derived datasets for research. These processes are often based on black boxes, on which clinical researchers are unaware of how the data were recorded, extracted, and transformed. In order to solve this, it is essential that extract, transform, and load (ETL) processes are based on transparent, homogeneous, and formal methodologies, making them understandable, reproducible, and auditable. This study aims to design and implement a methodology, according with FAIR Principles, for building ETL processes (focused on data extraction, selection, and transformation) for EHR reuse in a transparent and flexible manner, applicable to any clinical condition and health care organization. The proposed methodology comprises four stages: (1) analysis of secondary use models and identification of data operations, based on internationally used clinical repositories, case report forms, and aggregated datasets; (2) modeling and formalization of data operations, through the paradigm of the Detailed Clinical Models; (3) agnostic development of data operations, selecting SQL and R as programming languages; and (4) automation of the ETL instantiation, building a formal configuration file with XML. First, four international projects were analyzed to identify 17 operations, necessary to obtain datasets according to the specifications of these projects from the EHR. With this, each of the data operations was formalized, using the ISO 13606 reference model, specifying the valid data types as arguments, inputs and outputs, and their cardinality. Then, an agnostic catalog of data was developed through data-oriented programming languages previously selected. Finally, an automated ETL instantiation process was built from an ETL configuration file formally defined. This study has provided a transparent and flexible solution to the difficulty of making the processes for obtaining EHR-derived data for secondary use understandable, auditable, and reproducible. Moreover, the abstraction carried out in this study means that any previous EHR reuse methodology can incorporate these results into them.

Ion-/Thermo-Responsive fluorescent perylene-poly(ionic liquid) conjugates: One-pot microwave synthesis, self-aggregation and biological applications

This manuscript describes the attachment of alkylvinylimidazolium-based poly(ionic liquid) (PIL) to the imide positions of perylene bisimide (PBI) to introduce stimuli-responsiveness and to make the conjugate soluble in water and water-based mixed solvents with the possibilities of using them as a probe for imaging and diagnostics in biomedical domain. The alkylvinylimidazolium ionic liquid monomers (ILMs) are tailor-made and a one-step microwave-assisted method is employed for synthesizing the PBI-(Cys-PIL)2 conjugates by thiol-mediated radical polymerization of the ILMs using l-cysteine (Cys) with AIBN as initiator and in the presence of perylene-3,4,9,10-tetracarboxylic dianhydride (PDA). The introduction of PIL segment induces amphiphilicityto the conjugate, and it undergoes self-aggregation into vesicles in water and methanol/water mixture. Owing to the presence of PIL segments, the conjugates are responsive to anions forming insoluble spherical aggregates through the multipoint ionic crosslinking between the cationic PIL segments of neighbouring conjugate molecules in water and methanol/water mixture. The turbid color dispersion, containing spherical conjugate’s aggregates, shows upper critical solution temperature (UCST)-type phase transition to transparent solution upon heating. The variation of cloud point of conjugate could be done by changing different parameters such as molecular weight, nature of anions, and the length of the alkyl chain present in the PIL segment of the conjugate. The UV–vis and fluorescence spectra of the conjugate’s aggregates in solution change upon addition of anions. The monitoring of the spectral change upon heating due to disruption of aggregates allows us to determine the cloud point, which exactly matches with that obtain from turbidimetry. The water-soluble fluorescent PBI-(Cys-PIL)2 conjugate having cationic PIL segments shows low cytotoxicity and can be used in binding with ctDNA/plasmid DNA and imaging HeLa cells.

Reducing systematic review burden using Deduklick: a novel, automated, reliable, and explainable deduplication algorithm to foster medical research

BackgroundIdentifying and removing reference duplicates when conducting systematic reviews (SRs) remain a major, time-consuming issue for authors who manually check for duplicates using built-in features in citation managers. To address issues related to manual deduplication, we developed an automated, efficient, and rapid artificial intelligence-based algorithm named Deduklick. Deduklick combines natural language processing algorithms with a set of rules created by expert information specialists. MethodsDeduklick’s deduplication uses a multistep algorithm of data normalization, calculates a similarity score, and identifies unique and duplicate references based on metadata fields, such as title, authors, journal, DOI, year, issue, volume, and page number range. We measured and compared Deduklick’s capacity to accurately detect duplicates with the information specialists’ standard, manual duplicate removal process using EndNote on eight existing heterogeneous datasets. Using a sensitivity analysis, we manually cross-compared the efficiency and noise of both methods.DiscussionDeduklick achieved average recall of 99.51%, average precision of 100.00%, and average F1 score of 99.75%. In contrast, the manual deduplication process achieved average recall of 88.65%, average precision of 99.95%, and average F1 score of 91.98%. Deduklick achieved equal to higher expert-level performance on duplicate removal. It also preserved high metadata quality and drastically reduced time spent on analysis. Deduklick represents an efficient, transparent, ergonomic, and time-saving solution for identifying and removing duplicates in SRs searches. Deduklick could therefore simplify SRs production and represent important advantages for scientists, including saving time, increasing accuracy, reducing costs, and contributing to quality SRs.

Why We Need a New Outcomes-Based Value Attribution Framework for Combination Regimens in Oncology

BackgroundNovel oncology treatment strategies increasingly use medicines with distinct but complementary mechanisms of action in combination or in close sequence. Payers, when confronted with higher total cost of providing combination regimens involving multiple therapies and usually longer treatment durations, are reluctant to reimburse them, particularly when they perceive the expected incremental benefits from adding a new medicine (the add-on) to a currently reimbursed medicine (the backbone) not to represent value for money to the health system. Nevertheless, depending on how value is attributed to the add-on versus the backbone, a clinically effective medicine used as part of a regimen that increases treatment duration might be found “not cost-effective at zero price.” This phenomenon, signaling a policy problem not a pricing issue, first needs to be better understood before a generalizable and transparent solution can be presented. ObjectiveThis article sets out when this policy challenge arises and describes general principles that any proposed solution to the value attribution problem must satisfy. MethodsWe develop a simplified conceptual framework and use this to address 2 topics. The first is to understand the origin of problems posed by the current approach for attributing value in incremental cost-effectiveness analyses of combination regimens. The second is to discuss 2 new approaches in the literature designed to address the challenge. FindingsWe find that neither meets our criteria, meaning that further work is needed to resolve the issue. Finally, we briefly discuss the implications of relaxing the simplifying assumptions in our conceptual framework.

Alkyl chain length influence of hydrotrope on the pH responsiveness of surfactant aggregates based on dynamic imine bond

• Ionic hydrotropes with different chain length based on imine bond is prepared. • The pH responsiveness of solution by mixing CTAB and hydrotrope is explored. • The mechanism of different pH responsiveness of mixture is analyzed. The combination of pH-responsive hydrotropes and cationic surfactants is a novel way to construct pH-responsive surfactant aggregates. Herein, in order to investigate the chain length influence of hydrotrope on surfactant aggregate, three hydrotropes were formed from p-hydroxybenzaldehyde (HB) and added amine (hexylamine (HA), octylamine (OA), dodecylamine (DA)) respectively based on dynamic imine bonds. Then the surfactant aggregates were constructed by adding cetyltrimethyl ammonium bromide (CTAB). The molar ratio of CTAB: HB: HA/OA/DA was fixed at 100:55:55. The formation of imine bonds was proved by means of 1 H NMR measurement. Rheological measurements, and cryo -TEM were used to explore the pH responsiveness of the surfactant aggregates. The results showed that as pH increased from 6.0 to 12.0, the CTAB/HB/HA system changed from a low viscosity fluid to a viscoelastic fluid, as the CTAB/HB/OA system transformed from aqueous liquid via a transparent gel solution to a turbid fluid. On the other hand, the CTAB/HB/DA system can achieve four state transitions, from a non-viscosity fluid, via a viscoelastic fluid, turbid fluid and finally to a viscoelastic fluid. With the change of pH, the CTAB/HB/HA system turned from spherical to wormlike micelles, while CTAB/HB/OA experienced changes from spherical micelles via wormlike micelles to vesicles. Finally, the CTAB/HB/DA system was the most complex one, which converted from spherical micelles, wormlike micelles via vesicle, into final wormlike micelles. In conclusion, the sensitivity of pH responsiveness among these three systems gradually improved by increasing the chain length of the hydrotrope formed by HB and amine. This can be attributed to the different growth rates of the packing parameter. This work demonstrated the feasibility of constructing pH responsive surfactant aggregates by introducing hydrotropes to cationic surfactants.