Canadian Journal of Chemistry

The overuse and misuse of antibiotics are contributing factors that has led to the evolution of virulent bacterial strains that are resistant to first-line treatments. This has necessitated the development of novel agents to treat such pathogens, for which metal complexes have shown promise. In particular, the incorporation of ferrocene into a biologically active scaffold has shown documented success. Within this report, a series of three Ru-arene complexes with chelating 1,4-substituted 1,2,3-triazole ligands were synthesized and evaluated for their respective antibacterial activity against three clinically-relevant bacterial strains. Taken together, the subtle changes made to the ligands allowed for the determination of structure-activity relationships, where the inclusion of a ferrocene proved critical for antibacterial activity. Furthermore, the methyl group on the linker for complex RuTMFc embiggened its lipophilicity and protein binding, while the radical scavenging ability of the complex was diminished relative to RuTMFc which had unsubstituted hydrocarbon linker. This culminated with RuTMFc having the greatest antibacterial activity observed for all three complexes, while also exhibiting the lowest hemolytic activity.

Surface modification is a crucial strategy to enhance material performance and expand their applications across diverse fields. Among these, nature-inspired hydrophobic coatings have gained attention for their ability to address challenges such as environmental pollution, surface degradation, and efficiency loss in various industries, including optoelectronics, automotive, and outdoor structures. In this work, we present a comparative study of commercial alkyl and perfluoroalkyl silanes, (H3C(H2C)16H2CSiCl3) and (F3C(F2C)5(H2C)2SiCl3), dip coated on regular glass, with a focus on their stability and performance upon waterfall simulation and outdoor exposure. These coatings' wettability, optical properties, and stability on nanotextured glass are also studied. A video-based goniometer was used to study the wetting properties. Roughness, topography, and optical properties of the resulting surfaces were investigated by atomic force microscopy, and UV-Vis-NIR spectroscopy. At low deposition times, we were able to spot the presence of agglomerated regions of polymerized short perfluoroalkyl chains, leading to a rougher and less uniform film. In contrast, we observed smoother coating with fewer polymerized aggregates for long alkyl chains. We found that an enhancement in hydrophobicity and a decrease in reflectance was achieved with a short perfluorinated alkyl chain. When applied to nanotextured glass, the observed increase in reflectance for both coatings, at 500 nm, was likely due to the coating’s thickness effect. Texturing combined with surface roughness significantly increased the water contact angle, while only lowering the surface energy of regular glass without altering its structure resulted in less increase in water contact angle. These coatings can serve as hydrophobic surfaces and protective coatings against outdoor conditions, including dust accumulation, UV irradiation, ice adhesion, and corrosion.

A laboratory investigation was performed to regulate the physicochemical attributes—geomorphological and organizational, kinetic estates, and purposeful groups—of orange (Citrus × sinensis) and lemon (Citrus × limon) with a view toward a prospective adsorbent of toxic lead ions from aquatic solution. Outcomes demonstrated that optimal requirements for the Pb (II) removal are a preliminary concentration of 50 mg/L, an adsorbent mass of 0.2 g, and 6 and 4.4 as pH for orange peel and lemon peel, respectively. The investigational statistics were discussed via Freundlich, Langmuir, and D–R isotherm. Equilibrium statistics matched appropriately via Langmuir typical with a qmax of 16.76 mg/g for orange peel and 76.92 mg/g for lemon peel. The kinetic adsorption process was inspected and was adequately accomplished via a second-order equivalence. The characterization of lemon peel and orange peel was examined with a scanning electron microscope, Vis-IR spectroscopy, and GC-mass. The Pb(II) adsorption spontaneity onto orange peel is enhanced by enhancing temperature. The positive ∆H° (53.76 kJ/mol) estimate implies an endothermic system. The positive ∆S° (180.41 J/mol) estimate implies an enhanced randomness on the solid/liquid periphery during adsorption. In the case of lemon peel, the Pb(II) adsorption spontaneity is reduced by temperature. The negative ∆H° (−32.71 kJ/mol) estimate implied an exothermic adsorption nature. The ∆S° parameter was (−70.17 J/mol.K) for lemon peel, indicating that the Pb(II) in the bulk phase was more disorderly. Scanning electron microscopy exhibits a distinctive development in the adsorbent surface. The removal efficiency reached 92.34 and 90.4 for lemon peel and orange peel, respectively, at 0.2 mol/L KOH. Molecular electrostatic potential, frontier molecular orbital, and the density of states analysis were conducted to investigate the important active sites on the adsorption.

The relative stability and the conformational behavior of symmetric multihelicene isomers of formula C66H36 are analyzed by computational means. Our efforts to synthesize some of these molecules are also reported, in particular the observation of unexpected debromination when attempting to synthesize 13,14-dibromo[5]phenacene, and of unexpected reactivity of 13,14-dibromo[5]aphene when attempting its cyclotrimerization promoted by a nickel(0) complex.

Large facilities (big science) that provide advanced capabilities not available in researchers’ laboratories in universities and institutions have become increasingly indipensible to advance research and innovation. A synchrotron light source is one of such facilities crucial to chemical research. Herein, the entanglement of small science and big science in general is described with emphasis placed on the interplay of research in individuals’ laboratory (small science), and advanced tools at the synchrotron light source (big science) from the perspective of matching scientific problems with techniques at the synchrotron for solution, and the interaction of users with the staff and management of the facility (human activity). The discussion is focused on one phenomenon, X-ray absorption and related techniques, which are element specific and ideally suited for probing structure and bonding of materials and their functionality. I will describe why X-ray absorption spectroscopy is literally “Chemistry at the Edge”. The sociology of synchrotron research and its impact on science will also be presented. The evolution of synchrotron science and technology globally will be noted, especially the history of R&D of synchrotron research in Canada and the bright prospect for chemical research using future synchrotron light sources.

This article presents an overview of some of our developments of the chemistry of “frustrated Lewis pairs” (FLPs). We begin with a brief outline of the foundations of this discovery and applications of FLPs in hydrogenations. Recent advances in asymmetric hydrogenations and CO2 reduction are discussed. Early studies of FLPs with alkynes and olefins are introduced and shown to lead to the more recent uncovering of phosphino-phosphination reactions, affording a route to dissymmetric bidentate phosphines, a class of understudied ligands for transition metal catalysis. The concept of FLP is further expanding into alkali metal species, with applications in the chemistry with CO or H2 as well as Fischer–Tropsch chemistry. Efforts to use FLPs to model the reduction of N2 in Haber–Bosch type chemistry are also discussed. The concept of FLPs is applied to xenon difluoride chemistry and the fluorination of electron deficient boranes and borates affording new anions that offer potential applications in catalysis. Finally, the broad scope of chemistry where FLPs are being applied is briefly highlighted, demonstrating the impact of this concept around the world and across the periodic table.

Zirconium(IV) isopropoxide complexes supported by the ligands 2-pyridylamino-N , N-bis(2-methylene-4,6-dimethylphenolate), L1, 2-pyridylamino-N , N-bis(2-methylene-4,6-tert-amylphenolate), L2, and N , N-dimethyl-N , N-bis(2-methylene-4,6-dimethylphenolate)ethylenediamine, L3 (1–3) when combined with cocatalyst, 4-dimethylaminopyridine (DMAP) or bis(triphenylphosphine)iminium chloride, were assessed for the ring-opening copolymerization (ROCOP) of cyclohexene oxide (CHO), and phthalic anhydride (PA). Complex 1, when combined with DMAP, resulted in the highest polyester conversions and selectivity demonstrating the best activity for CHO/PA ROCOP. Kinetic studies with complex 1 determined an overall second-order rate law with a first-order dependence in CHO and catalyst concentrations, and a zero-order dependence in PA concentration. Moderate molar mass polymers with narrow dispersities were obtained and the polymers showed decomposition temperatures above 180 °C and glass transition temperatures of 43 °C.

The use of low-cost, widely available environmental friendly catalysts may strengthen the sustainability of lignocellulosic biomass conversion into levulinic esters. In this respect, the present study aimed to optimize the methyl esterification reaction between levulinic acid (LVA) and aluminum sulfate [Al2(SO4)3] with a view to producing methyl levulinate (MLV). The Box–Behnken design for three factors was applied to investigate the influence of reaction time (60, 120, and 180 min), alcohol:acid molar ratio (4:1, 8:1, and 12:1), and catalyst concentration (0.02, 0.04, and 0.06 mol L⁻¹) on LVA conversion into MLV. The reactions occurred in a Parr Instruments stainless steel reactor, at a temperature of 140 ºC and 733 rpm rotation. The results indicated that the interaction between molar ratio and catalyst concentration has a significant influence on LVA conversion. The regression model obtained is significant and predictive, with an R² value of 0.86. Analyses of response surfaces showed that a 60 min reaction time produces high conversion, irrespective of the amount of catalyst. Fixing the shortest reaction time and lowest Al2(SO4)3 concentration, the molar ratio indicated for the reaction would be 1:6. The levels selected provide conversions varying from 86.83% to 99.27%, demonstrating the efficiency of a low-cost catalyst at low concentrations.

In the present study, the synthesized samples indium oxide (In2O3), silver vanadate (Ag3VO4), and composite (In2O3/Ag3VO4) are prepared by using co-precipitation method. These samples showed a very effective photocatalytic response for the degradation of a dye methylene blue (MB) in the presence of sunlight. The physical properties of samples are characterized by XRD, scanning electron microscopy (SEM), FTIR, and ultraviolet (UV) spectroscopy. The structure analysis and crystalline size of prepared samples were examined by XRD. Debye Scherrer’s formula had been used to calculate the crystalline size and its value is 19.1 nm of In2O3, 10.8 nm of Ag3VO4, and 1.65 nm of In2O3/Ag3VO4. FTIR absorption spectroscopy was carried out in the range of 500–4000 cm⁻¹ to verify the synthesized material’s structural properties. FTIR spectrum also provides the information about the material’s functional groups. The morphology of indium oxide, silver vanadate, and composite was analyzed by SEM. The calculated grain sizes of indium oxide, silver vanadate, and In2O3/Ag3VO4 composite are 0.13, 0.72, and 0.56 µm, respectively. The optical properties indicate a small band gap for composite, which is 1.65 eV and showed strong absorption for sunlight. The photocatalytic degradation of MB was performed by using prepared catalysts in the presence of sunlight at wavelength 300–900 nm by UV spectroscopy. Indium oxide degraded MB to 76.5% and silver vanadate degraded MB to 71%, while the composite degraded MB to 85.5%. The results of UV spectroscopy showed that the composite is very effective in photocatalytic degradation MB dye.

Alternative to complex labelling of resorcinarene hosts with redox-active probes, noncovalent complex formation offers a unique avenue toward bifunctional hosts, which posses redox centers to transduce an electrochemical signal as well as maintaining a guest recognition site. Herein, N-alkyl ammonium resorcinarene halides (NARXs) hosts were evaluated with a well-known redox probe ferrocene (Fc). Specifically, the NARX hosts were designed based on the tuning of the resorcinarene upper rim to allow for hydrogen bonding, pi–pi stacking, ion and halogen binding interactions in organic environments. The NARX host induced a significant anodic shift of Fc E1/2; once formed, the Fc–NARX complex undergwent oxidation and reduction without Fc dissociation. Data indicate that hydrophobic interactions stabilize Fc interactions with the resorcinarene upper rim, which is directly related to the structural functionalization of the resorcinarene. Thus, we provide evidence for a controlled and tunable redox host–guest system with well-defined redox properties while maintaining the guest recognition site, suggesting that the host is bifunctional.

Single event upsets (SEUs) are a critical concern for reliability in semiconductor devices, particularly as technology nodes shrink and devices become more susceptible to cosmic rays and other radiation sources. Understanding and mitigating these effects are crucial for ensuring the reliability of electronic systems. By leveraging pulsed laser charge injection, researchers can achieve results comparable to traditional methods like heavy ion testing but at a lower cost and with better control over spatial and temporal parameters. The photogeneration effect in semiconductor devices due to single photon absorption and two-photon absorption is introduced and the test system designed to make use of both type of charge photogeneration is implemented. The design and development of the pulsed laser system at the Saskatchewan Structural Sciences Centre (SSSC) is described. The system's capabilities, such as precise control over pulse parameters and spatial targeting, make it a valuable tool for single event effect (SEE) analysis. The testing of a static random access memory (SRAM) using this newly developed system provides valuable insights into the device's behavior under radiation-induced faults. By quantifying overall error rates, including multiple-bit errors and faults in memory and control circuitry, researchers can assess the device's susceptibility to SEUs. Comparing the pulsed laser results of SRAM testing with those obtained from heavy ion testing demonstrates the effectiveness of the pulsed laser system. Overall, the new and unique Pulsed Laser System at the SSSC represents a significant advancement in SEE testing capability. Its ability to provide results comparable to traditional methods while offering greater accessibility and control has the potential to drive further innovation in the field of radiation effects analysis in semiconductor devices.

The substitution reaction mechanism of β-amino alcohols and thionyl chloride to form the 1-chloro-(2-alkylamino)ethane and the 1,2,3-alkyloxathiazolidine-2-oxide products was investigated using computational methods. The reactions that result in these compounds are very similar; they both use the N-(2-alkyl/arylamino)ethanols and thionyl chloride; however, the synthesis of 1,2,3-alkyl/aryloxathiazolidine-2-oxide requires the use of an amine base, which quite commonly results in a purer product, not a different compound as is the case here. The mechanism of the formation of 1-chloro-(2-alkylamino)ethanes involves the formation of a quaternary nitrogen species as one of the first steps. This step has a low relative energy barrier and occurs readily. It occurred in the reaction of all substituents tested except for the methyl and phenyl substituents. Based on this work, it was demonstrated that the amine base is not actually needed to form the 1,2,3-alkyl/aryloxathiazolidine-2-oxide. Experimental reactions to produce the 1-chloro-(2-alkylamino)ethanes were performed and the products were characterized by 1H and 13C-NMR and gas chromatography mass spectrometry (GC-MS). The GC-MS experimental results supported the computational results, in that trace amounts of the 1,2,3-oxathiazolidine-2-oxides were found in the residue of this reaction. This demonstrated that the 1,2,3-oxathiazolidine -2-oxides can be formed in trace amounts without a base. The base would be required to make the 1,2,3-alkyloxathiazolidine-2-oxides in higher yields. The computational chemistry results demonstrate that the amine base suppresses the quaternization of the nitrogen by reacting preferentially with the acidic protons, which is the normal mode of action of the amine base in thionyl chloride reactions.

A homologous series of pnictogen(III) dications supported by the terpyridine ligand has been prepared. The compounds contain Ph−PnIII (Pn = P, As, Sb, Bi) moieties and have been fully characterized using spectroscopic methods including single-crystal X-ray crystallography. The solid-state structure of the bismuth analogue revealed it to be a rare nine-coordinate bismuth dication, arising from the formation of several interionic interactions with the triflate anions. The Lewis acidities of these compounds have also been measured using experimental and computational methods and the results suggest they are moderate Lewis acids. The Sb and Bi compounds are air and moisture stable over extended periods of time, suggesting that they may be suitable Lewis acids for bench-top catalytic transformations.

The newly designed chromophores (BT1–BT7) of the highly unsaturated donor–acceptor (D–A) were theoretically analyzed and recommended for applications in organic solar cells (OSCs). Conjugated A-groups have been replaced in the reference (BTR) during its design. The structural and optoelectronic properties of designed molecules were calculated using density functional theory (DFT) and time-dependent DFT (TD-DFT) techniques. The frontier molecular orbitals study revealed that BT7 has the lowest energy gap of 2.01 eV, which is significantly less than BTR (2.34 eV), and a significant amount of charge transfer between highest occupied molecular orbital and lowest unoccupied molecular orbital has been observed. Out of all the newly designed chromophores in chloroform, the highest absorption spectra were found in the visible region with a bathochromic shift up to 768 nm. The dipole moment values of all the new chromophores (BT1–BT7) were significantly higher than the BTR (5.46 D), which resulted in good solvation. Electrostatic potential (ESP) analysis revealed electron distribution on various parts of the molecules by colored maps that are found to be effective for better intramolecular charge transfer (ICT). The electron transition density resulting from light absorption at different chemical sites was shown using TDM plots. The electron and hole reorganization energy values were proved as highly efficient in promoting charge mobility and hindered charge recombination for new compounds. By scaling our designed donor to the recognized acceptor Y6, which has demonstrated the creation of OSCs, the open circuit voltage of each molecule was ascertained. The designed molecules exhibited higher open circuit voltages than the reference, indicating improved and fine-tuned optoelectronic properties that would aid in the development of solar cell devices in the future.

Two structural problems concerning the prototropic and ring-chain tautomerism of pyrrolo[1,2-d]tetrazoles were clarified by means of DFT calculations. The first one concerns the carboxyethyl ester structure of the compound obtained by treating 7-methylpyrrolotetrazolide with ethyl chloroformate and the second one the structure of a precursor of a dye that was not a tetrazole as reported but 2-azido-5-chloro-1H-pyrrole-3,4-dicarbonitrile. Although the conclusions to the two problems have already been published elsewhere by one of the present authors (DM), the new NMR data of the aforementioned compound together with GIAO/B3LYP/6-311++G(d,p) calculations establish those conclusions on a solid basis. However, the most important thing about the present work is to establish that 1H-pyrrole is a peculiar azole, while the pyrrolide anion behaves like a classic azole.

In this study, we explored the growth of incongruently melting crystals in a starting solution with flux to better understand the role of flux in crystal growth mechanisms. We recorded the spectrum of BaBPO5 crystals across a 200–1400 cm⁻¹ range for detailed Raman spectroscopic analysis. The observed Raman bands corresponded to the vibrations of PO4 and BO4 units. These units link with B–O–P bonds via common corners to form PBO7 groups that serve as basic structural units of the crystal. Notably, these PBO7 structures remain stable at high temperatures up to the crystal melting point, at which the isolated PO4 groups predominantly exist in the melt, as revealed by high-temperature Raman spectroscopy. Further investigations into the Raman spectra of the starting solution enriched with BPO4 self-flux indicate that PBO7 groups are crucial for crystal growth. The addition of PBO4 flux aids in the formation of these PBO7 units. This research paves the way for expanding our understanding to other systems, which will help elucidate the mechanisms behind crystal growth.

Canola hull was proposed as a valuable precursor for activated carbon production, due to its abundance, low cost, and economic viability. This study aimed to develop a waste-based biosorbent from canola hulls by slow pyrolysis for effective CO2 capture. The biochar was synthesized from the canola hull using a fixed-bed tubular reactor through slow pyrolysis at various temperatures. The optimum biochar was activated using KOH as a chemical activating agent at different impregnation ratios. The biochar and activated carbon were characterized by elemental analysis, thermogravimetric analysis, surface textural analysis and FT-IR analysis. All the activated carbon samples with impregnation ratios of 0, 0.2, and 0.4 were screened at a total inlet mass flow rate of 100 mL/min (15% CO2 + 85% N2). Activated carbon prepared with an impregnation ratio of 0.4 (0.4AC) with a specific surface area of 1112 m2/g exhibited the highest adsorption capacity of CO2 (2.9 mmol/g) at 25°C under ambient pressure when the feed gas was 15% CO2). 0.4AC was chosen for further study at different feed compositions. The breakthrough curves were analyzed for the compositions 5%, 15% and 25% CO2 in feed, and the effects of adsorption parameters were discussed. The maximum CO2 uptake of the canola hull based activated carbon (0.4AC) is 13.0 mmol/g at ambient pressure and 25°C, with 100% CO2 inlet. Adsorption isotherm and kinetic were studied on the 0.4AC adsorbent. The canola hull based adsorbent with desirable physiochemical and surface textural properties can work as an effective adsorbent for CO2 capture.

With an increased demand for lithium ion (Li-ion) battery technologies, and the small number of lithium mines around the globe, there has been a heightened desire to develop new materials capable of extracting lithium from aqueous sources such as the ocean. To do so in an economically viable way, the materials must be highly selective toward the extraction of Li-ions so as not to necessitate the further purification from competing metal ions such as magnesium, sodium, or calcium. To address this, herein we report on three new conjugated imide compounds functionalized with the crown ether benzo-9-crown-3. The three new compounds Phth-CE, F-Phth-CE, and NMI-CE were synthesized via atom-economical condensation reactions between an amino functionalized benzo-9-crown-3 with commodity aryl imide building blocks. These three new compounds serve to develop an understanding of Li-ion capture via the benzo-9-crown-3 moieties scaffolded onto stable aromatic ring systems. The nodal plane between the aryl imide and the phenyl ring of benzo-9-crown-3 isolates the crown ether allowing for unhindered Li-ion capture and release. Subtle derivatization of the aryl imide showcases structural versatility to include a fluoride amenable to nucleophilic aromatic substitution and/or to act as a diagnostic handle and naphthalene unit extending optical absorption to longer wavelengths. Each new compound exhibits the formation of Li-ion sandwich complexes as determined by ⁷Li NMR spectroscopy, and near identical Li-ion extraction efficiencies, distribution coefficients, and selectivity under acidic conditions in neat and mixed-metal ion solutions as determined by triple quadrupole inductively coupled plasma mass spectrometry analysis.

Glucosinolates and their degradation products from Cleome gynandra L. are known for their beneficial effects in traditional medical use. As part of daily nutrient intake, the areal parts of this herb are cooked and consumed, whereas the residual water from boiling is discarded. However, it may contain valuable bioactive metabolites. Therefore, we focus our investigations on Cleome gynandra L. for the presence of glucosinolates using two extraction methods (conventional and unconventional) and according to the physiological stage of growth of the plant. The results showed that glucosinolate contents expressed in mg of glucocapparin/g dry matter (mg/g) differed quantitatively according to the extraction method and physiological development stage. Glucocapparin content was 8.24 mg/g dry matter for the methanolic extract (conventional method) compared to 5.01 mg/g dry matter for the aqueous extract at the fruiting stage of the plants. LC-MS and ¹H NMR analysis confirmed the identity of the major glucosinolate as glucocapparin. Quantification revealed the same variation trend in glucosinolate content according to the physiological stage of plant growth with the two extraction methods, i.e., 2.58, 4.74, and 5.01 mg glucocapparin/g dry matter for aqueous extracts (unconventional method) and according to the vegetative, flowering, and fruiting stages, respectively. However, it appears that aqueous extracts (cooking wastewater) obtained from areal parts of Cleome gynandra L. could constitute enriched extracts in glucosinolates from Cleome gynandra L. for phytoprotective applications from the fruiting stage.

Volcanic ash was used as a precursor for the synthesis of a geopolymer activated by sodium hydroxide and using hydrogen peroxide as a pore-forming agent. Factors controlling geopolymer synthesis such as sodium hydroxide concentration (6–12 mol/L), liquid/solid mass ratio (0.3–0.5), and H2O2 mass concentration (0%–2%) were optimized using the Box-Behnken design method. The chosen process variables were optimized to enhance both the geopolymer's porosity and its effectiveness in removing crystal violet. Sodium hydroxide concentration and H2O2 mass concentration had a significant effect on both responses. Under optimal conditions of 6 mol/L NaOH concentration, a 0.3 liquid/solid ratio, and 2% H2O2 mass concentration, the model-predicted and experimental values for both responses were highly comparable. Additionally, response surface methodology was used to assess the removal of crystal violet from an aqueous solution, employing the geopolymer produced under these optimal conditions as the adsorbent. Experiments were carried out according to the Box-Behnken statistical surface design with four input parameters, namely, contact time (A: 10–120 min), initial crystal violet concentration (B: 20–100 mg/L), adsorbent dose (C: 0.1–0.6 g), and pH (D: 3–9). Regression analysis indicated a strong fit of the experimental data to the second-order polynomial model, with a coefficient of determination (R²) of 0.9864 and a Fisher's F value of 61.97. Optimization of the parameters A (35.415 mg/L), B (98.184 min), C (0.359 g), and pH (6.950) achieved a maximum crystal violet removal of 98.413% by the geopolymer.

This study investigates dielectric relaxation in binary mixtures of 1,2-propanediol and 1,4-dioxane using time-domain reflectometry. The dielectric parameters, including the static dielectric constant, relaxation time, the Kirkwood correlation factor, excess properties, thermodynamic parameters, and Bruggeman factor, are analyzed to study molecular dynamics, dipole orientation, and intermolecular interactions within the mixture. The experimental results provide insights into the dielectric behavior of the binary system, with implications for various applications in material science, chemistry, and chemical engineering. The Luzar theory is applied to study the hydrogen bonding interaction in alcohols mixture. The results have been compared with our previously published work N.P. Garad et al. to study the effect of number of carbon atoms on dielectric properties.

Hydrogel is a three-dimensional polymer that can absorb large amounts of reagents while maintaining structural integrity. This material has been applied in many fields especially in smart agriculture. To improve the economic viability, the reusability of hydrogels in agricultural engineering over multiple cycles of adsorption and desorption is an urgent requirement. This can be solved if the crosslinker is used properly. Therefore, in this work, a series of porous semi-interpenetrating polymer network (IPN) hydrogels based on linear polyacrylamide, acrylamide, maleic acid, and N,N′-methylenebisacrylamide (MBA) were synthesized. The hydrogels were evaluated for the impact of MBA content on the characteristics and applicability as a urea fertilizer carrier. The chemical composition, morphology, mechanical, and rheological properties, swelling behavior, urea absorption, and desorption of hydrogels with crosslinker content in the range of 0.5%–2.0% were investigated. The porous structure was confirmed by scanning electron microscopy images. Changing the MBA content significantly affected all characteristics of the hydrogels. In particular, increasing the MBA content decreased the equilibrium swelling ratios in all investigated environments. The maximum amount of urea loaded into the hydrogel was also reduced from 435.88 to 188.50 mg/g. This increase also changed the swelling mechanism from non-Fickian to Fickian, whereas the urea release mechanism changed from Fickian to non-Fickian. Finally, the hydrogels demonstrated stability in soil over multiple cycles of water absorption and release. This study provides valuable insights into designing a semi-IPN hydrogel with desired properties that meet the application requirements of modern farming techniques.

In this study, the performances of a synthesized molecularly imprinted polymer (MIP) and a commercial solid phase extraction (SPE) cartridge were compared in terms of the removal efficiency and quantification of pharmaceutical compounds in wastewater samples. Concentration analysis of emtricitabine, tenofovir, naproxen, diclofenac, ibuprofen, and efavirenz was conducted in influent, primary effluent, secondary effluent, and post-chlorination water samples using liquid chromatography–UV detection. Regressions analysis revealed high linearity (R² values from 0.9980 to 0.9999) for the compounds, alongside recoveries ranging from 90.9% to 100%. The method detection limits were also determined. Removal efficiencies were computed, with naproxen and ibuprofen demonstrating complete removal (100%), while other compounds displayed different removal efficiency levels. The MIP was found to perform slightly better than traditional SPE cartridges in terms of selectivity, efficiency, and overall performance. This study provides valuable insights into the concentrations of target compounds at various treatment stages, emphasizing the importance of choosing extraction cartridges in wastewater treatment processes.

Many agricultural crops require both nitrogen (N) and phosphorus (P) fertilizers to sustain crop yields. However, long-term application of NH4–N fertilizers can cause soil acidification, which alters soil abiotic and biotic processes, including soil P dynamics. Long-term continuous wheat plots in Saskatchewan, Canada, were used to assess effects of N and P fertilization from 1967 and P fertilizer cessation in subplots from 1995. General soil chemical properties and soil P pools and forms were determined and then correlated with soil pH, total N (TN), and total P (TP) concentrations to show the relative importance on soil P dynamics of (a) crop nutrition (TN and TP); (b) soil acidification (pH); or (c) P fertilization/cessation. Fertilization with NH4–N decreased soil pH and altered exchangeable cation concentrations; however, long-term crop growth was poor in no-N plots and was best with both N and P fertilizers, in turn increasing soil carbon and organic matter. Applying P fertilizers without N increased soluble phosphates and the risk of P losses in runoff. Soil organic P (TPo) concentrations were correlated negatively to pH and positively to TN, but the concentrations of P compounds were not correlated to pH. This suggests that TPo accumulation may be from increased long-term crop residue inputs from crops with N and P fertilizers, rather than increased sorption from reduced pH. However, soil pH will continue to decrease with continued NH4–N fertilization, affecting soil chemistry and future P cycling; monitoring with a suite of wet chemistry and spectroscopic techniques is recommended.