Effect Of Chain Length Research Articles

Effect of ester chain length and anion on electrochemical properties of imidazolium dicyanamide ionic liquids: experimental and theoretical studies

Effect of ester chain length and anion on electrochemical properties of imidazolium dicyanamide ionic liquids: experimental and theoretical studies

On the role of surface stress in environment-assisted fracture

Abstract Environment effects in plasticity and fracture of metals, well studied for several decades, still pose many unanswered questions. A micro-mechanics explanation of how dislocation activity is influenced by the material surface state, that can answer these questions, has been elusive. We build on a recently discovered effect in metal cutting – organic monolayer embrittlement (OME) – wherein metal surfaces are rendered brittle by long-chain organic adsorbates, to explore how material state variables influence surface plasticity and fracture. In particular, cutting experiments with Al containing Self Assembled Monolayers (SAMs), show that the OME is controlled by surface stress (f) induced by the adsorbates. This is contrary to many instances of environment-assisted fracture which are usually attributed to surface energy changes, and wherein f is largely ignored. Other contributions include (a) a cantilever technique to measure surface stress, (b) demonstration of strong effect of SAM molecule chain length on f, (c) characterization of how dislocation activity at crack-tips is affected by adsorbate-induced f, and (d) large improvements in machining processes enabled by controlled environment-assisted fracture. We make the case that surface stress, due to adsorbates, likely influences all environmentally assisted cracking (EAC) phenomena, warranting a revisit of extant models of EAC.

SURFACE PROPERTIES AND MICELLIZATION OF SODIUM ALKYLSULPHATES IN THE PRESENCE OF LOW-MOLECULAR ALCOHOLS

The process of micellization of sodium alkyl sulfates (SAS : sodium decyl- (SDS) and dodecylsulfate (SDDS)) of formation in aqueous solution without or with alcohols including propanol-1, propanol-2 and butanol-1 and their adsorption behavior at air-liquid interface were investigated with both the tensiometry and the conductometry at 298 K. The effect of chain length of alcohol on micellar and interfacial properties were discussed. Some parameters including surface excess concentration (Γmax), minimum area per surfactant molecule (Smin) at air-liquid interface, degree of ionization of micelle, and standard free energy of adsorption and micellization, etc. are estimated. It was experimentally established that the introduction of 0.5-1.0 mol/dm3 of alcohols into surfactant solutions contributes to the process of micellar formation of SAS and increases the stability of the micellar phase, as evidenced by the observed synergistic effect on the critical micelle concentration (CMC). The addition of different alcohols changes the values of Γmax, Smin, CMC of SDS and SDDS and induces an increase in degree of ionization (β) of micelle relative to that in pure water. When alcohols are introduced into SDS and SDDS solutions, the degree of ionization of micelles at a constant length of the alkyl radical of surfactant moderately increases with increasing alcohol content in the solution and ranges from 0.50-0.73 and 0.38-0.75, respectively. Also, the effect of alcohol was discussed. The obtained thermodynamic parameters were used to confirm these behaviors of interfacial adsorption or micellization. An increase in chain length of alcohol promotes the micellization process. The CMC values decrease with increasing length of the alkyl radical of alcohols. Propanol-1, compared to propanol-2, somewhat reduces the value of SDS and SDDS CMC to a greater extent. Standard free energy of micellization ∆G0mic, also confirms the micellization behavior. Standard free energy of adsorption (∆G0адс) indicates that an increase in the chain length of alcohol in aqueous solution is favorable to the adsorption of SDS and SDDS at air-liquid interface. A comparison of the values of the standard free energy of adsorption and micelle formation in sodium alkyl sulfates – alcohols – water systems showed that adsorption is the most thermodynamically advantageous process in the studies systems, and the packing of surfactant “molecules” in micelles is less dense, compared to packing in a mixed adsorption layer.

State Transitions and Crystalline Structures of Single Polyethylene Rings: MD Simulations.

This study investigates the structural changes of cyclic polyethylene (PE) single chains during cooling through molecular dynamics simulations. The influence of topological constraint on a ring is examined by comparing it with the results of its linear counterpart. A pseudo phase diagram of state transition for PE rings based on length and temperature is constructed, revealing a consistent chain-folding transition during cooling. The shape anisotropy of short crystallized cyclic chains exhibits oscillations with chain length, leading to a more pronounced odd-even effect in single cyclic chains compared with the linear ones. A honeycomb model is proposed to elucidate the odd-even effect of chain folding in crystalline structures of single linear and cyclic chains, and we discuss its potential to predict surface tension. Analyses of the tight folding model and the re-entry modes demonstrate that a cyclic chain possesses a shorter average crystalline stem length and a more compact folded structure than its linear counterpart. The findings highlight the impact of topological change on crystallization and the odd-even effect of chain length, providing valuable insights for understanding polymer crystallization with different topologies.

Molecular dynamics simulations of betaine-based deep eutectic solvents with varying iso-alcohols chain lengths

Betaine-based (BET) deep eutectic solvents (DESs) made with isoalcohols of varying hydrocarbon chain lengths, namely triethylene glycol (TEG), 1, 2-ethanediol (ETD), 1, 3-propanediol (PPD) and 1, 4-butanediol (BTD) were modelled. Their effects on the formation of aqueous biphasic system (ABS) with 2 M dipotassium phosphate salt solution (K2HPO4) as well as the extraction of common protein molecules, bovine serum albumin (BSA), were studied using molecular dynamics simulation with Gromacs. Qualitative and quantitative data were used to analyse the simulation results, which includes visualised systems in equilibrium, root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration, radial distribution function (RDF) and hydrogen bond analysis. The results and literature research validated the role of inorganic salt solute concentration on the phase forming ability as well as the possibility of protein denaturation. More investigations and experimental works are to be carried out regarding the type of inorganic salt and its concentration for aqueous biphasic systems (ABSs) with alcohol based DESs and salt solution for protein extraction purposes. This is essential to understand the salting-out effect and to isolate the effects of hydrocarbon chain length from other influencing factors. Additionally, inorganic salt concentrations, presence of ether linkage as well as hydrocarbon chain length is shown to play a role in the dynamics between molecules in the system as well as protein conformational changes. Overall, ABS incorporating PPD and BTD with hydrocarbon chain lengths not exceeding C4 demonstrated superior performance in terms of protein conformational stability and interaction, showcasing their efficacy in protein extraction process.

Crystallization Kinetics of Phosphonium Ionic Liquids: Effect of Cation Alkyl Chain Length and Thermal History.

The effects of alkyl chain length on the crystallization kinetics and ion mobility of tetraalkylphosphonium, [P666,n][TFSI], (n = 2, 6, 8, and 12) ionic liquids were studied by differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS) over a wide temperature range. The liquid-glass transition temperature (Tg) and ion dynamics examined over a broad T range were almost insensitive to structural modifications of the phosphonium cation. In contrast, the crystallization kinetics were strongly affected by the length of the fourth alkyl chain. Furthermore, the thermal history of the sample (cold vs melt crystallization) significantly impacted the crystallization rate. It has been found that the nature of crystallization phenomena is the same across the homologous series, while the kinetic aspect differs. Finally, electric conductivity in supercooled liquid and crystalline solid phases was measured for all samples, revealing significant ionic conductivity, largely independent of the cation structure.

Amphiphilic polymeric particles based on gradient and block copoly(2-oxazoline)s: Interplay between structure and Pickering emulsion properties

Pickering emulsions (PEs) offer enhanced stability and reduced toxicity compared to conventional emulsions. Recent advances in polymer chemistry have introduced poly(2-alkyl/aryl-2-oxazoline)s (PAOx) as promising alternative emulsifying materials. Known for their biocompatibility, tunability, and stability, PAOx can be rapidly synthesized via microwave-assisted methods. This study explores the use of amphiphilic and non-water-soluble PAOx to stabilize PEs through the formation of polymeric particles (PPs) via nanoprecipitation. Preliminary screening identified HLB5.0 PAOx as effective in forming well-defined PPs. We then investigated the effects of chain length and monomer distribution on the properties of PPs and PEs. Unlike block-based particles, the use of gradient PAOx allowed modulation of the particles’ glass transition temperature while maintaining their size and wettability. In Pickering emulsion formulations, PPs demonstrated effective surface coverage at low concentrations (≈ 0.9 wt%), with DP100-based particles providing enhanced stability and tunable viscosities. The formation of high internal phase PEs further highlights the applicative potential of PAOx, offering broad application prospects in various industries, including biomedicine, pharmaceuticals, and cosmetics.

Effect of alkyl chain length on the thermal properties and toxicity of n-alkyl-ammonium nitrate ionic liquids (n = 2, 3, 4, 5, 6, 8) for energy applications

AbstractThe most currently used ionic liquids (ILs) are protic ionic liquids (PILs), subject to extensive investigation regarding their physical properties. These compounds along with their mixtures with other substances such as salts and solvents, serve as electrolytes in next generation electrochemical smart devices, and emerge as viable candidates to replace conventional Heat Transfer Fluids (HTFs) in various energy applications. Despite the extensive number of studies, important information about this kind of compounds is still unknown, such as the effect of alkyl chain length on thermal and thermophysical properties, as well as toxicity. This work, extending previous studies of our group, summarizes the liquid range, heat capacity and acute toxicity level of six ammonium ILs: specifically, n-alkyl-ammonium nitrate ILs with increasing alkyl chain length (n = 2, 3, 4, 5, 6, 8). For this study, the synthesis of the three ILs with the longest alkyl chain was performed, along with DSC, TGA and toxicity measurements. It was observed that an increase in alkyl chain length resulted in a decrease in short-term thermal stability and an increase in melting temperature, indicating a reduction in the liquid range. A compensation effect between enthalpy and entropy of melting was observed for the studied chain lengths. The isobaric specific and molar heat capacities increase with temperature for all the compounds studied here, and good correlations were obtained between molar heat capacity and the number of carbon atoms in the alkyl chain for every temperature. Finally, most of the ILs are non-toxic, although toxicity increases with alkyl chain length.

The Effect of β-Sheet Secondary Structure on All-β Proteins by Molecular Dynamics Simulations.

The effect of β-sheet ratio and chain length on all-β proteins was investigated by MD simulations. Protein samples composed of different repeating units with various β-sheet ratios or a different number of repeating units were simulated under a broad temperature range. The simulation results show that the smaller radius of gyration was achieved by the protein with the higher proportion of β-sheet secondary structure, which had the lower nonbonded energy with more HBs within the protein. The root mean square deviation (RMSD) and the root mean square fluctuation (RMSF) both increased with temperature, especially in the case of a longer chain. The visible period was also shown according to the repeated secondary structure. Several minimum values of RMSF were located on the skeleton of Cα atoms participating in the β-sheet, indicating that it is a kind of stable secondary structure. We also concluded that proteins with a short chain or a lower ratio of β-sheet could easily transform their oriented and compact structures to other ones, such as random coils, turns, and even α-helices. These results clarified the relationship from the primary level to the 3D structure of proteins and potentially predicted protein folding.

Stability and lipid oxidation of oil-in-water emulsion stabilized by Maillard conjugates of soybean phosphatidylethanolamine with different polysaccharides

Lipid oxidation and instability in oil-in-water (O/W) emulsion are the main challenges in emulsion-based foods. Polysaccharide-induced Maillard conjugation of soybean phosphatidylethanolamine (SP) holds great potential in improving physicochemical stability of emulsions. This work applied tamarind gum, pectin, inulin and maltodextrin to conjugate with SP to obtain the four Maillard conjugates (MCs), and investigated their difference in interface and anti-oxidant abilities in emulsions. Results showed that lower polymerization degree of polysaccharide moieties (tamarind gum＞pectin＞maltodextrin＞inulin) caused higher glycation degree in MC: inulin-SP-MC＞maltodextrin-SP-MC＞pectin-SP-MC ≈ tamarind gum-SP-MC, which corresponded their color changes. Compared with unconjugated mixtures, interface activity and anti-oxidant abilities of MCs were strengthened. Among the four MCs, tamarind gum-SP-MC (7.77 mN/m) and pectin-SP-MC (8.42 mN/m) could decrease interfacial tension more largely. It was due to the faster interface saturation benefited from broader steric network of tamarind gum and pectin moieties, and stable interfacial absorption facilitated by improved zeta potential and lipophilicity. Pectin-SP-MC also exhibited the highest anti-oxidant ability (DPPH scavenging ability of 97.81% and ferric-reducing antioxidant power of 2.742 A). It was attributed to the combined effects of grafting degree, interface activity and chain length of pectin moiety. As a result, emulsions stabilized by pectin-SP-MC had less water loss, smaller droplet sizes, and lower contents of oxidation products. Maillard reaction between SP and pectin was favorable to produce MCs with higher potential for the improvements of physical and oxidative stability of O/W emulsions.

Diffusion of curcumin in PLGA-based carriers for drug delivery: a molecular dynamics study

Context:The rapid growth and diversification of drug delivery systems have been significantly supported by advancements in micro- and nano-technologies, alongside the adoption of biodegradable polymeric materials like poly(lactic-co-glycolic acid) (PLGA) as microcarriers. These developments aim to reduce toxicity and enhance target specificity in drug delivery. The use of in silico methods, particularly molecular dynamics (MD) simulations, has emerged as a pivotal tool for predicting the dynamics of species within these systems. This approach aids in investigating drug delivery mechanisms, thereby reducing the costs associated with design and prototyping. In this study, we focus on elucidating the diffusion mechanisms in curcumin-loaded PLGA particles, which are critical for optimizing drug release and efficacy in therapeutic applications.Methods:We utilized MD to explore the diffusion behavior of curcumin in PLGA drug delivery systems. The simulations, executed with GROMACS, modeled curcumin molecules in a representative volume element of PLGA chains and water, referencing molecular structures from the Protein Data Bank and employing the CHARMM force field. We generated PLGA chains of varying lengths using the Polymer Modeler tool and arranged them in a bulk-like environment with Packmol. The simulation protocol included steps for energy minimization, T and p equilibration, and calculation of the isotropic diffusion coefficient from the mean square displacement. The Taguchi method was applied to assess the effects of hydration level, PLGA chain length, and density on diffusion.Results:Our results provide insight into the influence of PLGA chain length, hydration level, and polymer density on the diffusion coefficient of curcumin, offering a mechanistic understanding for the design of efficient drug delivery systems. The sensitivity analysis obtained through the Taguchi method identified hydration level and PLGA density as the most significant input parameters affecting curcumin diffusion, while the effect of PLGA chain length was negligible within the simulated range. We provided a regression equation capable to accurately fit MD results. The regression equation suggests that increases in hydration level and PLGA density result in a decrease in the diffusion coefficient.

Detection of volatile hydroperfluoroalkanes during hydrothermal liquefaction of perfluoroalkyl carboxylic acids at circumneutral pH

Hydrothermal liquefaction (HTL) is a promising technology for converting wet organic waste such as sewage sludge into biocrude oil while simultaneously destroying per- and polyfluoroalkyl substances (PFAS). This study tracked the fate and degradation of six representative PFAS in water to address the effect of perfluoroalkyl chain length on degradation rates and the formation of volatile transformation products at 300–350 °C. While perfluorosulfonic acids were recalcitrant, perfluoroalkyl carboxylic acids (PFCAs) were rapidly and completely decarboxylated to hydroperfluoroalkanes (1 H-perfluoroheptane in the case of perfluorooctanoic acid). The volatile hydroperfluoroalkane was subsequently defluorinated without detectable fluorocarbon intermediates yielding 30–60 % defluorination for ammonium perfluoro(2-methyl-3-oxahexanoate), perfluorobutanoic acid and perfluorooctanoic acid after 2 h at 350 °C. Increasing temperature (especially at 350 °C) and longer perfluoroalkyl chains substantially enhanced the defluorination. This is the first study to report volatile hydroperfluoroalkanes from PFCAs in HTL, raising concern about the potential emission of long-lived greenhouse gasses into the atmosphere, but also opening new avenues for PFAS destruction through HTL.

Effect of hydrocarbon chain length of alkyl trimethyl ammonium bromide on corrosion inhibition of stainless steel in sulfuric acid

Effect of hydrocarbon chain length of alkyl trimethyl ammonium bromide on corrosion inhibition of stainless steel in sulfuric acid

Different Chain Length Tannic Acid Preparations as Coating Agents for Zein Nanoparticles

Proteins that are amphiphilic and have low water solubility can self-assemble into nanoparticles useful in food science, pharmaceutical science, or biotechnology. However, protein nanoparticles exhibit drawbacks such as low stability unless the particles are coated. In the current study, tannic acid is the coating agent for nanoparticles synthesized from the protein zein. Tannic acid is a hydrolyzable tannin comprising a polyol esterified with galloyl residues. The nominal molecular formula of tannic acid (C76H52O46) suggests the material is decagalloyl glucose, obscuring its complex composition as a mixture of galloyl esters of glucose. We prepared hollow zein nanoparticles and coated them with tannic acid preparations that had short or long galloyl ester chains. The % α-helix of zein in nanoparticles is lower than in native zein but there is no effect of coating the particles with tannic acid. Interactions between the tannic acid and the zein slightly perturb the IR spectrum of the protein but there is no effect of galloyl chain length. We confirmed that tannic acid-coated particles have a more negative zeta potential, suggesting greater stability compared to uncoated particles. Coating with longer chain length tannic acid reduces particle diameter and tends to decrease polydispersity but does not change particle digestibility. Coating with shorter galloyl chain length tannic acid tends not to change particle diameter, reduces polydispersity of the particles, and stabilizes particles to enzymatic digestion. Tannic acid is a naturally occurring tunable coating for nanoparticles that can be used to adjust properties such as particle size, polydispersity, and digestibility for specific purposes.

Silanization Strategies for Tailoring Peptide Functionalization on Silicon Surfaces: Implications for Enhancing Stem Cell Adhesion.

Biomaterial surface engineering and the integration of cell-adhesive ligands are crucial in biological research and biotechnological applications. The interplay between cells and their microenvironment, influenced by chemical and physical cues, impacts cellular behavior. Surface modification of biomaterials profoundly affects cellular responses, especially at the cell-surface interface. This work focuses on enhancing cellular activities through material manipulation, emphasizing silanization for further functionalization with bioactive molecules such as RGD peptides to improve cell adhesion. The grafting of three distinct silanes onto silicon wafers using both spin coating and immersion methods was investigated. This study sheds light on the effects of different alkyl chain lengths and protecting groups on cellular behavior, providing valuable insights into optimizing silane-based self-assembled monolayers (SAMs) before peptide or protein grafting for the first time. Specifically, it challenges the common use of APTES molecules in this context. These findings advance our understanding of surface modification strategies, paving the way for tailoring biomaterial surfaces to modulate the cellular behavior for diverse biotechnological applications.

Elucidating solvent effects on lipase-catalyzed peroxyacid synthesis through activity-based kinetics and molecular dynamics.

Peroxyacid synthesis is the first step in Prilezhaev epoxidation, which is an industrial method to form epoxides. Motivated by the development of a kinetic model as a tool for solvent selection, the effect of solvent type and acid chain length on the lipase-catalyzed peroxyacid synthesis was studied. A thermodynamic activity-based ping-pong kinetic expression was successfully applied to predict the effect of the reagent loadings in hexane. The activity-based reaction quotients provided a prediction of solvent-independent equilibrium constants. However, this strategy did not achieve satisfactory estimations of initial rates in solvents of higher polarity. The lack of compliance with some assumptions of this methodology could be confirmed through molecular dynamics calculations i.e. independent solvation energies and lack of solvent interaction with the active site. A novel approach is proposed combining the activity-based kinetic expression and the free binding energy of the solvent with the active site to predict kinetics upon solvent change. Di-isopropyl ether generated a strong interaction with the enzyme's active site, which was detrimental to kinetics. On the other hand, toluene or limonene gave moderate interaction with the active site rendering improved catalytic yield compared with less polar solvents, a finding sharpened when peroctanoic acid was produced.

Efficient Synthesis of Mannopyranoside-based Fatty Acyl Esters: Effects of Acyl Groups on Antimicrobial Potential.

The approval of Sucrose Fatty Acid Esters (SFAEs) as food additives/ preservatives with antimicrobial potential has triggered enormous interest in discovering new biological applications. Accordingly, many researchers reported that SFAEs consist of various sugar moieties, and hydrophobic side chains are highly active against certain fungal species. This study aimed to conduct aregioselective synthesis of SAFE and check the effect of chain length and site of acylation (i.e., C-6 vs. C-2, C-3, C-4, and long-chain vs. short-chain) on antimicrobial potency. A direct acylation method maintaining several conditions was used for esterification. In vitro tests, molecular docking, and in silico studies were conducted using standard procedures. In vitro tests revealed that the fatty acid chain length in mannopyranoside esters significantly affects the antifungal activity, where C12 chains are more potent against Aspergillus species. In terms of acylation site, mannopyranoside esters with a C8 chain substituted at the C-6 position are more active in antifungal inhibition. Molecular docking also revealed that these mannopyranoside esters had comparatively better stable binding energy and hence better inhibition, with the fungal enzymes lanosterol 14-alpha-demethylase (3LD6), urate oxidase (1R51), and glucoamylase (1KUL) than the standard antifungal drug fluconazole. Additionally, the thermodynamic, orbital, drug-likeness, and safety profiles of these mannopyranoside esters were calculated and discussed, along with the Structure-Activity Relationships (SAR). This study thus highlights the importance of the acylation site and lipid-like fatty acid chain length that govern the antimicrobial activity of mannopyranoside-based SFAE.

Effects of side chain length on the performance of poly(aryl-alkylene) anion exchange membranes for fuel cells

Anion exchange membranes (AEMs) are one of the most critical materials determining the fuel cell (FC) performance. From current reports, there are still many limit factors for AEMs, such as conductivity, mechanical performance, power density and durability, which greatly affect their practicality. Here, we introduce a range of arylfluoroketone monomers with different side chain lengths into the poly (aryl-alkylene) matrix material using a copolymerization strategy to get AEMs. This study aims to investigate the effect of side chain length on the performance of AEMs, such as phase separation, ion conductivity and mechanical properties. Due to the existence of long alkyl side chains, QTPNPC4 shows significant hydrophilic aggregation, outstanding OH− conductivity (158.6 mS cm−1, 80 °C) and excellent flexibility (109.1 %). Meanwhile, QTPNPC4 exhibits remarkable ex-situ durability (96.3 %) and chemical stability (96.6 %) after soaking in a 2 M NaOH solution for 1560 h at 80 °C. In addition, the peak power density (PPD) of a single cell with QTPNPC4 reaches 927 mW cm−2 (80 °C), and the membrane has good in-situ durability (0.689 mV h−1).

Exploring molecular mechanism of fish myofibrillar protein adsorbing and releasing aldehydes with different structures

Expounding the interaction effect between myofibrillar proteins (MPs) and odorants for directional regulation of fish flavor is necessary. Interactive relationship between MPs and six aldehydes contributed to fish aroma with different chain lengths and saturations were investigated via multiple spectroscopy and molecular docking. Aldehydes binding capabilities to fish MPs in the order: Decanal> Hexanal> (E)-2-Decenal> (E)-2-Nonenal> (E,E)-2,4-Decadienal> (E,E)-2,4-Heptandienal. Each mole of MPs can bind about 2660 mol Dec while as to HDE just about 1000 mol due to the effect of chain length and saturation. The change of hydrophobic cavity in MPs contributed to the difference in aldehyde-binding capacity. Tryptophan and tyrosine residues of MPs mediated changes in the hydrophobic microenvironment. Besides, hydrogen bonding and Van der Waals forces were the main force dominated the interaction. Further, it described the molecular mechanism about MPs and aldehydes interaction and proposed a method to disrupting the interactions between MP and fishy odor compounds to help fish product aroma control.

Advancements in polyol synthesis: expanding chemical horizons and Néel temperature tuning of CoO nanoparticles

The polyol synthesis of CoO nanoparticles (NPs) is typically conducted by dissolving and heating cobalt acetate tetrahydrate and water in diethylene glycol (DEG). This process yields aggregates of approximately 100 nm made of partially aligned primary crystals. However, the synthesis demands careful temperature control to allow the nucleation of CoO while simultaneously preventing reduction, caused by the activity of DEG. This restriction hinders the flexibility to freely adjust synthesis conditions, impeding the ability to obtain particles with varied morpho-structural properties, which, in turn, directly impact chemical and physical attributes. In this context, the growth of CoO NPs in polyol was studied focusing on the effect of the polyol chain length and the synthesis temperature at two different water/cations ratios. During this investigation, we found that longer polyol chains remove the previous limits of the method, allowing the tuning of aggregate size (20–150 nm), shape (spherical-octahedral), and crystalline length (8–35 nm). Regarding the characterization, our focus revolved around investigating the magnetic properties inherent in the synthesized products. From this point of view, two pivotal findings emerged. Firstly, we identified small quantities of a layered hydroxide ferromagnetic intermediate, which acted as interference in our measurements. This intermediate exhibited magnetic properties consistent with features observed in other publications on CoO produced in systems compatible with the intermediate formation. Optimal synthetic conditions that prevent the impurity from forming were found. This resolution clarifies several ambiguities existing in literature about CoO low-temperature magnetic behavior. Secondly, a regular relationship of the NPs' TN with their crystallite size was found, allowing us to regulate TN over ~ 80 K. For the first time, a branching was found in this structure-dependent magnetic feature, with samples of spheroidal morphology consistently having lower magnetic temperatures, when compared to samples with faceted/octahedral shape, providing compelling evidence for a novel physical parameter influencing the TN of a material. These two findings contribute to the understanding of the fundamental properties of CoO and antiferromagnetic materials.