Radical Solution Research Articles

Preparation of low‐temperature self‐crosslinking acrylic resin and its performance research

AbstractAcrylic resin, as a common coating and adhesive, possesses excellent heat resistance, weather resistance, and is inexpensive, making it widely used in industries related to automotive, construction, electronics, fabrics, and other sectors essential to our daily life. Traditional acrylic resin not only pollutes the environment but also poses certain health risks. Therefore, we studied the synthesis of a low‐temperature self‐crosslinking acrylic emulsions were synthesized by free radical solution polymerization using methyl methacrylate (MMA), butyl acrylate (BA), acrylic acid (AA), diacetone acrylamide (DAAM), hydroxypropyl acrylate (HPA), epoxy resin (E‐51) as the monomers, vinyltriethoxysilane (A‐51) as the coupling agent, and adipic dihydrazide (ADH) as the cross‐linking agent. This water‐based acrylic resin undergoes a crosslinking reaction between the carbonyl group of DAAM and the hydrazide group of ADH, substantially improved the drying speed and adhesion compared to unmodified versions, and also improved the thermal stability. The contact angle of the film increased from 72.8° to 86.9° with the increase of the degree of cross‐linking, and the mechanical properties were improved by 60%. This study provides a suitable formulation for preparing water‐based acrylic resins with superior performance.

The Causal Effect of Candidate Extremity on Citizens’ Preferences: Evidence from Conjoint Experiments

Abstract Previous studies demonstrate that politicians’ issue positions and rhetorical style have grown increasingly extreme. It remains unclear, however, whether extremity pays off electorally. Using two preregistered conjoint experiments conducted in the United States (N = 2,006) and Israel (N = 1,999), we investigate whether citizens reward or penalize candidates for taking extreme positions (i.e., proposing radical solutions to societal problems) and using an extreme rhetorical style (i.e., communicating in a way that signals rigidity and dogmatism). The results are consistent in showing that extremity is costly for candidates. Across countries, citizens penalize both in-party and out-party candidates for both extreme positions and an extreme rhetorical style, and the average penalty for being extreme is a 16-percentage-point decrease in candidate support. Our results are in line with scholarship demonstrating that citizens disapprove of elite extremity. They also indicate that citizens react independently to elites’ substantive policy positions and their communication style.

Observation of dynamic nuclear polarization echoes.

It is demonstrated that the time evolution of the electron-nuclear polarization transfer process during pulsed dynamic nuclear polarization (DNP) can be reversed on a microsecond timescale, leading to the observation of DNP echoes. The DNP echoes are induced by consecutive application of two pulse trains that produce effective Hamiltonians that differ only in the sign of the effective hyperfine coupling. The experiments have been performed on a frozen solution of trityl radicals in water/glycerol on a homebuilt X-band electron paramagnetic resonance/DNP spectrometer at 80 kelvins. We envisage that DNP echoes will play an important role in future development of pulsed DNP for sensitivity-enhanced nuclear magnetic resonance, hyperfine spectroscopy, and quantum sensing.

How is feasibility in local climate politics constructed? Balancing between appropriateness and consequence in advancing urban low-carbon plans

ABSTRACT How does ambitious climate action become politically feasible? The literature has tended to understand political feasibility through interactions between citizens and governing institutions, conditioned by the various costs and benefits for the actors involved. Instead, by considering the work of bureaucratic actors, this paper examines the practices of constructing feasibility in local climate planning. We draw on sociological institutionalism, focusing on the dynamics of fine-tuning between logics of appropriateness and consequence in achieving what is deemed ‘politically feasible.’ Taking climate politics in the City of Bergen (Norway) as a case study, this paper advances that what is deemed politically feasible is a product of calibrating (1) relevant policies with the city’s climate ambitions, (2) specific actions with open and inclusive processes, and (3) radical and ambitious solutions with the city’s current political climate. We discuss the implications of these results for the legitimization of climate planning locally.

Lepidium peruvianum as a Source of Compounds with Anticancer and Cosmetic Applications

Lepidium peruvianum—an edible herbaceous biennial plant distributed in the Andes—has been used for centuries as food and as a natural medicine in treating hormonal disorders, as an antidepressant, and as an anti-osteoporotic agent. The presented study aims to prove its beneficial cosmetic and chemopreventive properties by testing the antiradical, whitening, cytotoxic, and anticancer properties of differently colored phenotypes that were extracted using three solvents: methanol, water, and chloroform, with the help of the chemometric approach to provide evidence on the impact of single glucosinolanes (seven identified compounds in the HPLC-ESI-QTOF-MS/MS analysis) on the biological activity of the total extracts. The tested extracts exhibited moderate antiradical activity, with the methanolic extract from yellow and grey maca phenotypes scavenging 49.9 ± 8.96% and 48.8% ± 0.44% of DPPH radical solution at a concentration of 1 mg/mL, respectively. Grey maca was the most active tyrosinase inhibitor, with 72.86 ± 3.42% of the enzyme activity calculated for the water extract and 75.66 ± 6.21% for the chloroform extract. The studies in cells showed no cytotoxicity towards the human keratinocyte line HaCaT in all studied extracts and a marked inhibition of cell viability towards the G361 melanoma cell line, which the presence of pent-4-enylglucosinolate, glucotropaeolin, and glucoalyssin in the samples could have caused. Given all biological activity tests combined, the three mentioned compounds were shown to be the most significant positive contributors to the results obtained, and the grey maca water extract was found to be the best source of the former compound among the tested samples.

Effect of ionic bonding on luminescence properties of histidine maleic anhydride derivatives

Polymeric materials exhibiting room-temperature phosphorescent (RTP) have attracted wide attention for their easy synthesis, low toxicity, and applications in various fields such as data encryption, cell imaging, information security and other fields. Nevertheless, the conventional ways of preparing such materials are mainly focused on doping, which may suffer from phase separation, poor compatibility, and lack of effective methods to promote intersystem crossing and suppress the nonradiative deactivation rates. Herein, a series of polymers with fluorescence and phosphorescence dual emission were prepared by simple radical solution copolymerization. Through rigid ion-bonded cross-linked networks and cross-linked hydrogen-bonded networks between the polymer chains, the non-radiative jumps and achieve ultra-long phosphorescence lifetimes were able to suppress. By suppressing non-radiative transitions through rigid ion-bonded cross-linked networks and intermolecular hydrogen-bonding networks between polymer chains, ultra-long phosphorescence is achieved. Impressively, a LRTP lifetime of up to 815.38 ms in polymers under ambientconditions is set up. Moreover, in this study, phosphorescence emission can be easily tuned by balancing ion radius and charge states. These results outline the construction of polymeric materials, endowing traditional polymers with new characteristics and promising potential applications.

Feasibility of managing and organizing the problem of informal settlements a field study on informal areas in Najaf Governorate

The research aims to study the problem of informal housing in Najaf Governorate, present strategic scenarios to solve the problem, as well as choosing the low-cost construction strategy as an approved strategy in the research. The study included (9) areas in which informal housing units spread, namely (Al-Radhwiya, Al-Rahma neighborhood, Al-Najaf Sea depression, Al-Shawafi area, behind Al-Quds neighborhood, Al-Jadidah II slums, Al-Jadidah III slums, Tabuk neighborhood, Al-Barakiyah), affiliated to the Najaf Governorate Municipality Directorate. The researchers used the descriptive analysis method based on structured personal interviews in informal areas to identify the problem, in addition to using financial tools by calculating costs (fixed capital, working capital) and revenues to solve the problem by submitting a proposal to establish a low-cost residential complex. The study reached several conclusions, the most important of which is that efforts and procedures can be organized to reach a radical solution by choosing the optimal and fastest scenario, which is building low-cost housing units, and benefiting from the areas on which slums were built. The study recommended a set of recommendations, the most important of which is forming a government working group from the departments concerned with urban planning, the municipality, the Investment Authority, and departments related to infrastructure, to prepare a technical study and an action plan to establish a package of projects distributed across the governorate's areas. These projects are granted to the best investors in establishing low-cost housing units, and forming a subcommittee to evaluate the lands and re-use them in an optimal manner. In a way that achieves benefit for the city, whether by converting them into green spaces, parks, or investment projects that enhance commercial activity in the city.

Synthesis and reactivity of the di(9-anthryl)methyl radical.

The di(9-anthryl)methyl (DAntM) radical was synthesized and investigated to elucidate its optical, electrical properties, and reactivity. The generation of the DAntM radical was confirmed by its ESR spectrum, which showed two broad signals. The unpaired electron is primarily localized on the central sp2 carbon and slightly delocalized over the two anthryl moieties. Although the DAntM radical undergoes dimerization in solution, the radical still remains even at 190 K due to the bulky nature of the two anthryl groups. Interestingly, upon exposure to air, the purple color of the radical solution quickly fades to orange, resulting in decomposition to give 9-anthryl aldehyde and anthroxyl radical derivatives.

A radical solution to the Hubble tension problem

The Hubble tension has proven to be stubbornly persistent, despite widespread efforts to relax it. As a possible resolution of this problem we propose a radical alternative to the way in which cosmological models are viewed. Specifically, we consider building cosmological models from spaces that exhibit intrinsic symmetries, rather than as space-times with explicit symmetry. This change in perspective allows statistical homogeneity and isotropy to be maintained, while relaxing some strong mathematical constraints that the standard approach imposes. We show that a Hubble tension arises naturally in our new approach, and that (as a corollary) a prediction can be made for the radial component of the Baryon Acoustic Oscillations. Our prediction appears to be consistent with the DESI first-year data release, which has otherwise been interpreted as evidence for dynamical dark energy.

A Radical Strategy for the Alkylation of Amides with Alkyl Halides by Merging Boryl Radical-Mediated Halogen-Atom Transfer and Copper Catalysis.

Amide alkylation is a fundamental process in organic chemistry. However, the low nucleophilicity of amides means that divergent coupling with alkyl electrophiles is often not achievable. To circumvent this reactivity challenge, individual amine synthesis followed by amidation with standard coupling agents is generally required. Herein, we demonstrate a radical solution to this challenge by using an amine-borane complex and copper catalysis under oxidative conditions. While borohydride reagents are generally used as reducing agents in ionic chemistry, their conversion into amine-ligated boryl radicals diverts their reactivity toward halogen-atom transfer. This enables the conversion of alkyl halides into the corresponding alkyl radicals for amide functionalization via copper catalysis. The process is applicable to the N-alkylation of primary amides employing unactivated alkyl iodides and bromides, and it was also showcased in the late-state functionalization of both complex amide- and halide-containing drugs.

Synthesis and Evaluation of Poly (Trifluoroethyl Methacrylate) Binders as a Polyvinylidene Fluoride Alternative for Lithium‐Ion Batteries

The binder, a critical electrode component, significantly influences lithium‐ion batteries (LIB) performance, yet remains an under‐researched area. The widespread use of polyvinylidene fluoride (PVDF) as a commercial binder is challenged by its surging cost, attributed to limited production and increased demand, highlighting the necessity for alternatives. Here, we synthesize poly (trifluoroethyl methacrylate) (PTFEMA), a polymer with a molecular weight in the million range, through a straightforward radical solution polymerization method, aiming to use it as a cathode binder for LIBs. PTFEMA demonstrate good stability across the typical operating temperatures and voltages, along with robust adhesion to the current collector. Moreover, the PTFEMA outperforms PVDF in terms of electrolyte affinity and lithium‐ion conductivity, thereby achieving capacity and stability comparable to those of its PVDF counterparts. This investigation confirms the homopolymer form of PTFEMA as a compelling alternative to PVDF, representing a valuable exploration of binder technology for LIBs.

A phosphate glass reinforced composite acrylamide gradient scaffold for osteochondral interface regeneration

The bone-cartilage interface is defined by a unique arrangement of cells and tissue matrix. Injury to the interface can contribute to the development of arthritic joint disease. Attempts to repair osteochondral damage through clinical trials have generated mixed outcomes. Tissue engineering offers the potential of integrated scaffold design with multiregional architecture to assist in tissue regeneration, such as the bone-cartilage interface. Challenges remain in joining distinct materials in a single scaffold mass while maintaining integrity and avoiding delamination. The aim of the current work is to examine the possibility of joining two closely related acrylamide derivatives such as, poly n-isopropyl acrylamide (pNIPAM) and poly n‑tert‑butyl acrylamide (pNTBAM). The target is to produce a single scaffold unit with distinct architectural regions in the favour of regenerating the osteochondral interface. Longitudinal phosphate glass fibres (PGFs) with the formula 50P2O5.30CaO.20Na2O were incorporated to provide additional bioactivity by degradation to release ions such as calcium and phosphate which are considered valuable to assist the mineralization process. Polymers were prepared via atom transfer radical polymerization (ATRP) and solutions cast to ensure the integration of polymers chains. Scaffold was characterized using scanning electron microscope (SEM) and Fourier transform infra-red (FTIR) techniques. The PGF mass degradation pattern was inspected using micro computed tomography (µCT). Biological assessment of primary human osteoblasts (hOBs) and primary human chondrocytes (hCHs) upon scaffolds was performed using alizarin red and colorimetric calcium assay for mineralization assessment; alcian blue staining and dimethyl-methylene blue (DMMB) assay for glycosaminoglycans (GAGs); immunostaining and enzyme-linked immunosorbent assay (ELISA) to detect functional proteins expression by cells such as collagen I, II, and annexin A2. FTIR analysis revealed an intact unit with gradual transformation from pNIPAM to pNTBAM. SEM images showed three distinct architectural regions with mean pore diameter of 54.5 µm (pNIPAM), 16.5 µm (pNTBAM) and 118 µm at the mixed interface. Osteogenic and mineralization potential by cells was observed upon the entire scaffold's regions. Chondrogenic activity was relevant on the pNTBAM side of the scaffold only with minimal evidence in the pNIPAM region. PGFs increased mineralization potential of both hOBs and hCHs, evidenced by elevated collagens I, X, and annexin A2 with reduction of collagen II in PGFs scaffolds. In conclusion, pNIPAM and pNTBAM integration created a multiregional scaffold with distinct architectural regions. Differential chondrogenic, osteogenic, and mineralized cell performance, in addition to the impact of PGF, suggests a potential role for phosphate glass-incorporated, acrylamide-derivative scaffolds in osteochondral interface regeneration.

A Radical Solution to Nucleophilic Substitution: Photocatalyzed Phosphinylation of Alkyl Halides at Room Temperature

A Radical Solution to Nucleophilic Substitution: Photocatalyzed Phosphinylation of Alkyl Halides at Room Temperature

Slums effect on urban sustainability: Suggested planning mechanisms for development

Slums are considered one of the largest problems that threaten our urban environment, and their negative impact is exacerbated by the passage of time without a radical solution. This research investigated measures that are successful in achieving sustainable urban development within slums or surrounding urban areas. Reducing the negative aspects accompanying the traditional remedies for this phenomenon, which Iraq is currently suffering from, has become a widespread trend in most Iraqi cities. As a result, there emerged belts surrounding urban areas, causing severe repercussions, some of which can be addressed. However, most problems are challenging to address because they affect the urban structure. In Iraqi cities, slums are a feature of the city’s transformation phase, distorting their essence. This phenomenon directly and indirectly affects sustainable urban development by conflicting with one of the most important pillars of sustainable development: not to pass on problems to future generations. Over the past decade, our cities have been formed with slums being a large part of their structure. This poses significant challenges for future generations, which will be difficult to solve unless we proactively address them with effective solutions to mitigate their impact. After reviewing various remedies for this problem, it was found that the proposed treatments were unsuitable for the Iraqi situation. The research proposes the idea of exchange (land versus time). When comparing this strategy with the rest of the treatments, it has been found to be the best solution for slums in Iraq, meeting the requirements of sustainable urban development.

Carbon Recycling of High Value Bioplastics: A Route to a Zero-Waste Future.

Today, 98% of all plastics are fossil-based and non-biodegradable, and globally, only 9% are recycled. Microplastic and nanoplastic pollution is just beginning to be understood. As the global demand for sustainable alternatives to conventional plastics continues to rise, biobased and biodegradable plastics have emerged as a promising solution. This review article delves into the pivotal concept of carbon recycling as a pathway towards achieving a zero-waste future through the production and utilization of high-value bioplastics. The review comprehensively explores the current state of bioplastics (biobased and/or biodegradable materials), emphasizing the importance of carbon-neutral and circular approaches in their lifecycle. Today, bioplastics are chiefly used in low-value applications, such as packaging and single-use items. This article sheds light on value-added applications, like longer-lasting components and products, and demanding properties, for which bioplastics are increasingly being deployed. Based on the waste hierarchy paradigm-reduce, reuse, recycle-different use cases and end-of-life scenarios for materials will be described, including technological options for recycling, from mechanical to chemical methods. A special emphasis on common bioplastics-TPS, PLA, PHAs-as well as a discussion of composites, is provided. While it is acknowledged that the current plastics (waste) crisis stems largely from mismanagement, it needs to be stated that a radical solution must come from the core material side, including the intrinsic properties of the polymers and their formulations. The manner in which the cascaded use of bioplastics, labeling, legislation, recycling technologies, and consumer awareness can contribute to a zero-waste future for plastics is the core topics of this article.

Long-Term Drying Shrinkage Strain of Engineered Cementitious Composite Concrete Contains Polymeric Fibers

The lack of concrete tensile stress endurance led to the invention of engineered cementitious composite. However, the absence of gravel from the mixture in addition to the high binder content may lead to high shrinkage strain. Therefore, a radical solution to this problem is worth to be anticipated. The importance of this research lies in investigating the long-term drying shrinkage strain of the engineered cementitious composite since there is a lack of information regarding this behavior. Mixes of 30 and 60 MPa strengths were produced with polyvinyl alcohol fibers PVA-ECC and polypropylene fibers PP-ECC. The drying shrinkage strain of PVA-ECC mixes has been compared to PP-ECC mixes for both short term (0–28 days) and long term (0–360 days). Results indicated that all PVA-ECC mixes exhibited lower drying shrinkage strains than PP-ECC mixes. The ultimate drying shrinkage strain was recorded to be 1200 microstrain at 28 days. The increment in drying shrinkage strain after 28 days was 5.6% in PVA-ECC mixes when compared to that in PP-ECC mixes which was 6.77%. For high strength levels, the drying shrinkage strain at the age of 360 days declared a reduction of 3.5% for PVA-ECC compared to PP-ECC mixes. Also, it was lower for mixes with 60 MPa (6.3%) than for mixes with 30 MPa (7.6%). Therefore, despite the higher cement content for mixes with 60 MPa strength, the higher fiber volume fraction and the higher PVA solution percentage restricted the drying shrinkage strain increment. The research also addresses some mechanical tests of engineered cementitious composite concrete such as compressive strength, flexural strength, and strain capacity that may provide a strong relation to the drying shrinkage behavior of the different mixes. The scanning electron microscope images were involved in this research to declare the impact of fiber types on the microstructure of the ECC mixes.

Starch as a smart, cheap, and green gatekeeper for the controlled release of propyl gallate from antioxidant biodegradable packaging films

Oxidative rancidity of food products and massive consumption of plastic packaging have put the necessity in manufacturing novel antioxidant biodegradable packaging films. A comprehensive investigation was conducted on starch/poly(butylene adipate-co-terephthalate) (PBAT) antioxidant blown films, in which starch acted as a gatekeeper for the controlled release of propyl gallate (PG). PG was well integrated into the matrices and bound to starch molecules by hydrogen bonding. All films showed strong anti-ultraviolet performance, and higher oxygen barrier than the traditional polyethylene film. Increasing starch proportions promoted the swelling of films and the release of PG, thereby causing higher antioxidant activity at the same contact time to free radical solutions. Similar polarity made PG prone to partition and rapid migration into the food simulants with higher ethanol concentration and the high-fat-content peanut butter. The film with 20:80 w/w starch/PBAT proportion and 3% w/w PG content effectively suppressed the oxidation of peanut butter within 300-day storage. Findings demonstrated this strategy for manufacturing starch/PBAT antioxidant films as a long-term active packaging in food industry.

Experimental confirmation of the formation of collective modes of the magnetization motion of paramagnetic particles in dilute solutions due to spin exchange

Experimental confirmation of the manifestations of new spin exchange paradigm in EPR spectra of 14N nitroxide radical solutions is presented. It was shown that in the region of relatively low concentrations of radicals, the two side components of the spectrum have a mixed shape (the sum of the absorptive line and dispersive line). The dispersion contributions in these two lines have opposite signs. As the concentration of radicals increases, the contribution of dispersion passes through an extremum and in the region of maximum contribution of dispersion, the contribution of absorption to these two lines changes sign. In the region of high concentrations of radicals, when one homogeneously broadened line is practically observed, it turns out that these side components have resonant frequencies that do not coincide with the frequency of the center of gravity of the spectrum.

Effects and Mechanism of Hyperbranched Phosphate Polycarboxylate Superplasticizers on Reducing Viscosity of Cement Paste.

The adsorption behavior and dispersing capability of hyperbranched phosphated polycarboxylate superplasticizers (PCEs) containing phosphate monoester and phosphate diester were investigated. The hyperbranched structures were constructed using a special monomer dimethylaminoethyl methacrylate (DMAMEA) to create the branches during the polymerization. Meanwhile, the polymer architectures were tailored by varying the content of phosphate monoester and phosphate diester in the backbone via free radical solution polymerization. In contrast to comb-like PCE, hyperbranched PCEs presented a weaker dispersion capability at w/c = 0.29, but with a lower water-to-cement ratio (w/c), the hyperbranched PCEs exhibited a better dispersion capability than the comb-like PCEs. The dynamic light scattering (DLS) and transmission electron microscope (TEM) analysis showed that the adsorption layer of hyperbranched PCEs were thicker than that of comb-like PCEs. A thicker adsorption layer thickness generated thinner diffusion water layer thickness. The increase of the free water amount due to the thinner water diffusion layer is the key mechanism for improving the dispersibility and decreasing the viscosity of cement paste.

Investigation of the inverse fracture occurrence in X65 Q&T pipeline steels under impact loading, Part I: Experiments

This study treats over the sudden cleavage fracture occurrence, sometimes called “reverse fracture”, in drop-weight tear testing of X65 Q&T seamless pipeline steel. This phenomenon is not new and has been around since new manufacturing techniques such as thermomechanical controlled processes (TMCP) and seamless techniques have emerged over the last 40 years. Yet, there is no radical plausible solution for this problem as due to its stochastic nature makes it difficult to systematically study the cause and effect of catastrophic mechanisms. Here, certain key pieces of information are added to the existing body of results on this subject matter such as automated identification of cleavage sites via deep learning YOLO framework. In conjunction with advanced SEM/EBSD analysis and TEM description provide strong evidence of the nature of the microstructure and its connection with the abnormal fracture behavior.