Cavity Size Research Articles

Controlling product selectivity and catalyst lifetime by altering acid strength, cavity size of SAPO, and diffusion rate of methanol in the MTO reaction: DFT and MD calculations.

The initiation mechanisms of the MTO process over silicoaluminophosphate (SAPO) catalysts with zeolite-like structures using first-principles calculations have been investigated. The supramolecular system of silicoaluminophosphates consisting of inorganic cages with Brønsted acid sites and trapped organic compounds was used as a catalyst in the MTO reaction. To study the structure-property relationship in more detail, the effect of acidity and cage size of different types of SAPOs (SAPO-18, SAPO-34, and SAPO-17 with CHA, AEI, and ERI structures, respectively) in the aromatic cycle of hydrocarbon pool mechanism was investigated. The differences in reaction barriers can be explained by the cage size, pore topology, and environment of framework protons of materials. Product selectivity was controlled by using cavity-type zeolite, the steric constraint of the cavity for the formation of critical intermediates, and acidic strength. The results show that ethylene selectivity increases as the cavity size decreases, and the elliptical pore size of the structures decreases, thereby decreasing the acidity of the zeolite structure, leading to an increase in propylene selectivity. SAPO-18 exhibits the longest reaction lifetime and has the highest amount of carbonaceous material after reaction completion. SAPO-17 with small pore and cavity size is selective to ethylene, although it shows a rapid catalyst deactivation rate.

Experimental and numerical study of the post-impact behavior of a water droplet impacting on a hydrophilic surface with a cylindrical cavity

In this study, we couple a laboratory experiment with numerical simulations to investigate the post-impact behavior of a water droplet impacting a hydrophilic surface with a cylindrical cavity. In the experiment, we observe that either an increase in the depth of the cavity or a decrease in its diameter will promote crown formation, and the crown will be higher but narrower on a deeper or narrower cavity. Moreover, a higher impact speed leads to a larger crown. The numerical simulations of post-impact droplet behavior are in good agreement with the experimental results. More importantly, they shed light on the physics underlying the formation and development of the crown by computing the forces induced on the bottom, vertical wall, and surrounding wall of the cavity as the droplet impacts there. The simulations suggest that the cavity size and the impact speed play significant roles in determining the force profiles and thus whether a crown forms and, if so, how large it is. On the basis of the experimental and numerical results, we construct regime diagrams for the crown formation by considering the critical values of cavity size and impact speed.

Metal-organic cages for gas adsorption and separation.

The unique high surface area and tunable cavity size endow metal-organic cages (MOCs) with superior performance and broad application in gas adsorption and separation. Over the past three decades, for instance, numerous MOCs have been widely explored in adsorbing diverse types of gas including energy gases, greenhouse gases, toxic gases, noble gases, etc. To gain a better understanding of the structure-performance relationships, great endeavors have been devoted to ligand design, metal node regulation, active metal site construction, cavity size adjustment, and function-oriented ligand modification, thus opening up routes toward rationally designed MOCs with enhanced capabilities. Focusing on the unveiled structure-performance relationships of MOCs towards target gas molecules, this review consists of two parts, gas adsorption and gas separation, which are discussed separately. Each part discusses the cage assembly process, gas adsorption strategies, host-guest chemistry, and adsorption properties. Finally, we briefly overviewed the challenges and future directions in the rational development of MOC-based sorbents for application in challenging gas adsorption and separation, including the development of high adsorption capacity MOCs oriented by adsorbability and the development of highly selective adsorption MOCs oriented by separation performance.

Role of cavity in a Mach 8 axisymmetric scramjet combustor: Flame stabilization vs combustion enhancement

The cavity-assisted scramjet has been proven to be the most promising propulsion system for air-breathing hypersonic vehicles. In this paper, numerical simulations of a Mach 8 axisymmetric scramjet combustor are conducted and validated to investigate the effect of the cavity. The results indicate that the combustion state undergoes significant changes as the combustion heat release increases. Detailed analysis reveals that the role of the cavity in flame stabilization and combustion enhancement also changes with combustion heat release. Under weak heat release conditions, the high-speed environment results in reduced combustion efficiency, and the primary role of the cavity is to stabilize the flame. Increasing the cavity size does not yield significant gains but could bring redundant mass. As heat release intensifies, the combustion enhancement effect of the cavity becomes more prominent. The presence of the cavity dramatically improves fuel combustion efficiency. The distribution of supersonic and subsonic combustion modes, as well as that of premixed and diffusion combustion modes, is also affected by cavity size and combustion heat release. In the engineering development of scramjets, it is suggested that the design of the cavity flameholder should involve careful consideration of combustion heat release.

Efficacy of a high concentration of nano silver fluoride in preventing caries: A randomized controlled trial.

To investigate the effectiveness of a novel agent containing Nano Silver Fluoride 1500 (NSF 1500) and chitosan to inactivate carious lesions in children. The study included eighty children. While both groups had fluoride dentifrice applied to their teeth, only the experimental group received treatment with the NSF 1500-ppm solution. The first and sixth-month interval examinations were conducted by two calibrated dentists (k = 0.85). The NSF 1500 group had 69.2% of their teeth with arrested decay, while the control group had 24.1%. The difference was statistically significant (p 0.001), with a preventive fraction of 59.4%. The number needed to treat (NNT) was approximately two. The NSF 1500 formulation was more effective than toothbrushing alone with fluoridated dentifrice in preventing dental caries. The effectiveness of NSF 1500 is determined by the size and depth of the dental cavity. Its ability to arrest caries lesions was comparable to previously tested products, NSF 400 and NSF 600. Key words:Preventive dentistry, dental caries, nanoparticles.

Monte Carlo-based in-depth morphological analysis of medullary cavity for designing personalized femoral stem.

The design of femoral stem prostheses requires a precise understanding of the femoral marrow cavity. Traditional measurements of morphological parameters in the upper femur, particularly the medullary cavity and cortical region, are primarily based on coronal and sagittal axes, which may not fully capture the true three-dimensional structure of the femur. Propose a Monte Carlo-based method for a more comprehensive analysis of the femoral marrow cavity, using CT scans of femurs from a selected group of patients. The study aimed to define and calculate anatomically semantic morphological parameters to enhance the understanding of the femoral marrow cavity's anatomical morphological changes, ultimately improving the design and clinical selection of femoral stem prostheses. To enhance the accuracy of femoral stem prosthesis design, this study aims to develop a Monte Carlo-based method for a more comprehensive analysis of the femoral marrow cavity. The proposed method transforms the non-random problem of determining cross-sectional size into a random issue, allowing for the calculation of the size of the medullary cavity and cortical region. Anatomically semantic morphological parameters are then defined, calculated, and analyzed. The experimental results indicate that the newly defined parameters complement existing ones, providing a more rational scientific basis for understanding the anatomical morphological changes of the femoral marrow cavity. This research offers essential scientific theoretical support for improved morphologic research, design, and clinical selection of femoral stem prostheses. It holds significant importance and application value in clinical practice, contributing to a more accurate and comprehensive understanding of femoral anatomy for prosthetic design.

Exclusive ion recognition using host-guest sandwich complexes.

Ion recognition in porous aqueous media utilizing polyethers involves the formation of 1 : 1 and higher-order host-guest complexes. The effectiveness of these interactions relies on the optimal size of the host cavity to encapsulate the guest ions. While liquid/liquid extraction based on host-guest interactions offers higher specificity in metal ion extraction, it results in the co-extraction of unwanted coordinating solvents and counter-anions. Therefore, an improved protocol is required by which the ion can be selectively trapped within the host cavity and simultaneously decrease the guest coordination with the outside environment. This study delves into the microscopic mechanisms underpinning the exclusive ion recognition through the formation of 2 : 1 host-guest sandwich complexes, which reduce metal coordination with solvent or counter-ions, ensuring selectivity. Our analysis shows that ions with a radius larger than the host cavity, such as cesium (Cs+), form stable host-guest sandwich complexes at elevated host concentrations. In this study, we performed molecular dynamics simulations to investigate the microscopic details of Cs+ interactions with open-chain and preorganized polyethers, namely podand, crown, and cryptand in electrolyte media. Our findings reveal that the formation of stable Cs+-crown sandwich complexes significantly reduces Cs+ coordination with H2O and NO3-. This loss of solute coordination leads to exclusivity in bound metal ions, offering a potential strategy for efficient solvent extraction.

APPLYING SIX SIGMA TO IMPROVE THE DEFECT RATE OF ELECTRONIC COMPONENTS: A SIX SIGMA CASE STUDY

This study aimed to improve the touch responses of electronic products. The improvement method was based on six sigma improvement steps. Product quality was improved using define, measure, analyse, improve, control (DMAIC) and statistical quality control methods to reduce the cost and waste of defective products. The project identified five critical processes from the manufacturing process and eight critical to characteristics (CTCs). Then CTCs were identified through the critical to characteristic diagram. The root causes were verified using the experimental plan method, scatter diagram, and double ratio test. This study identified three root causes, namely ‘poor reed touch value’, ‘base cavity width’, and ‘jig precision’. The last two causes were evaluated, and countermeasures were taken to ‘change the size of the base cavity’, ‘change the design of the assembly jig’, and ‘change the process of the assembly jig’. The target rate of the overall product defect rate reached 127%.

ЭКСПРЕССИЯ ОКСИТОЦИНА И ПРОСТАГЛАНДИНА Е2 В МИОМЕТРИИ ПРИ СЛАБОСТИ РОДОВОЙ ДЕЯТЕЛЬНОСТИ

We examined 66 postpartum women (average age 27.6±2.3 years) who were on duty at the postpartum department of the 3rd City Clinical Hospital named after E.V. Klumova, Minsk for 2022–2024. The first inclusion included 34 patients whose birth ended with an emergency cesarean section. The comparison group included 32 patients with cesarean section caused by reasons not related to the weakness of labor. An immunohistochemical study of the expression levels of oxytocin (OT) and prostaglandin E2 (PG E2) in myometrial tissues obtained from the lower segment of the uterus during cesarean section was carried out using antibodies Oxytocin, Prostaglandin. Studies of potassium content in tissues were carried out using high-performance liquid chromatography. It was found that in patients with impaired contractile function and hypotonic dysfunction of the uterus, a strong inverse relationship was revealed between the tone of the uterus and the size of the uterine cavity (correlation coefficient r = -0.9751; p < 0.001; 95% confidence interval) and a strong direct relationship between the tone of the uterus and index of resistance of the uterine vessels (correlation coefficient r = 0.93712; p = 0.001; 95% confidence interval), which reflects a close association between a decrease in myometrial contractility and its tone. During postpartum uterine subinvolution, compared with physiological birth, an unreliable increase in the expression of oxytocin and prostaglandin E2, respectively, to 8.94 ± 2.8 and 21.47 ± 3.2 and an unreliable decrease in the level of potassium in tissues was revealed, which dictates the search for other pathognomonic and diagnostic markers violations of the contractile function of the uterus and its hypotension during childbirth.

The counteracting influence of 2-hydroxypropyl substitution and the presence of a guest molecule on the shape and size of the β-cyclodextrin cavity.

The aqueous solubility of β-cyclodextrin (β-CD), a cyclic carbohydrate comprising seven α-D-glucose molecules, is enhanced by 2-hydroxypropyl (2-HP) substitution of the hydroxyl groups at the CD rims. Our thorough analysis of the structural and solvation properties with different degrees of 2-hydroxypropyl substitution on β-CD using molecular dynamics simulations reveals that the solubility is enhanced at the cost of the structural distortion of the CD cyclic structure. Substitution at the secondary rim predominantly enhances the favourable interactions between CD and water by decreasing CD-CD hydrogen bonding and promoting CD-water hydrogen bonding. However, the effect of substitution at the primary rim on the CD-water interactions is minimal; the hydrogen bonds between water and the primary hydroxyl group in native CD merely get replaced by those between water and 2-HP, since the substitution makes the primary hydroxyl oxygen (O6 atom) inaccessible to water. In contrast, substitution at the primary rim maintains the structural integrity of CD, while substitution at the secondary rim results in structural distortion due to the disruption of the intramolecular hydrogen bond belt, even leading to cavity closure. Certain strategic substitutions of the primary hydroxyl groups can help in the reduction of structural distortion, depending upon the degree of substitution at the secondary hydroxyl rim. A detailed inspection of the simulation trajectory revealed that the tilting of glucose units with the primary hydroxyl oxygen (O6) pointing inward is the primary driver for cavity closure. Even though the dynamics of glucose tilting can influence the kinetics of host-guest complex formation, once the guest is well incorporated into the cavity, glucose tilting is inhibited and the cavity opens up as in native β-CD.

The motion of micro-swimmers over a cavity in a micro-channel.

This article combines the lattice Boltzmann method (LBM) with the squirmer model to investigate the motion of micro-swimmers in a channel-cavity system. The study analyses various influential factors, including the value of the squirmer-type factor (β), the swimming Reynolds number (Rep), the size of the cavity, initial position and particle size on the movement of micro-swimmers within the channel-cavity system. We simultaneously studied three types of squirmer models, Puller (β > 0), Pusher (β < 0), and Neutral (β = 0) swimmers. The findings reveal that the motion of micro-swimmers is determined by the value of β and Rep, which can be classified into six distinct motion modes. For Puller and Pusher, when the β value is constant, an increase in Rep will lead to transition in the motion mode. Moreover, the appropriate depth of cavity within the channel-cavity system plays a crucial role in capturing and separating Neutral swimmers. This study, for the first time, explores the effect of complex channel-cavity systems on the behaviour of micro-swimmers and highlights their separation and capture ability. These findings offer novel insights for the design and enhancement of micro-channel structures in achieving efficient separation and capture of micro-swimmers.

Flow control by circular cavities in lateral flow porous membranes.

This research explores the flow penetration in porous media by virtue of capillary action and geometric control of the liquid imbibition rate in microfluidic paper-based analytical devices (μPADs) having applications in food quality management, medical diagnostics, and environmental monitoring. We examine changes in flow resistance and membrane geometry, aiming to understand factors influencing capillary penetration rates for various practical applications. We conducted experiments and simulations using lateral porous membranes and altered the flow resistance by changing the liquids or the paper channel geometry by adding cavities. From experiments, it was revealed that by creating a circular cavity in the paper channel, the penetration rate was sufficiently altered. Moreover, increasing the cavity size and type of liquid (w.r.t. viscosity) also caused a decrease in the flow rate. Imbibition rates were also influenced by the position of the cavities in the paper channel. The maximum delay for water was almost 2 times with a 16 mm circular cavity located at 3 cm from strip bottom edge. Overall, we attained a maximum delay in the case of castor oil which was almost 85 times slower than water and 3.7 times slower than olive oil. A good agreement was observed with CFD analysis. We believe that this research would help in developing advance techniques to enhance the flow control strategies in μPADs and indicators.

NANOSPONGE FOR ENHANCING SOLUBILITY AND BIOAVAILABILITY OF ORAL DRUGS: REVIEW

New developments in nanoparticle-based oral medicine have resulted in a profusion of studies to improve the solubility, permeability, and chemical stability of various medications. Nanosponges (NSs) are one type of carriers utilized in this many carrier systems. NSs are nanosized carriers with a sponge-like shape. They have hydrophilic cavities and hydrophobic branches, which aid in the loading of both hydrophilic and hydrophobic medicines. Nano-sponges have a 3-dimensional network and a nanometric cavity size. NSs are very porous, with the capacity to entrap active moieties and the advantage of controlled release. These tiny sponges circulate in the body to reach a specific place and release the medicine in a controlled and predictable manner, assisting in the resolution of numerous issues such as drug toxicity and low bioavailability. One of their significant impacts is the ability to enhance oral absorption and bioavailability. The primary goal of this review is to provide brief updates on NSs for increasing medicine oral absorption as well as their evolutions in loading drugs for enhancing their oral deliverability and treatment of a variety of diseases.

Host-guest interaction induced room-temperature phosphorescence enhancement of organic dyes: a computational study.

To achieve the effective regulation of organic room temperature phosphorescence (RTP) in supramolecular systems, the elucidation of host-guest interactions in RTP is of vital importance. Herein, we employed two organic dyes (PYCl and PYBr) and their four host-guest complexes with CB[6] and CB[7] and explored the mechanism of host-guest interaction induced RTP enhancement using quantum mechanics/molecular mechanics (QM/MM) approach. For the two organic dyes, we found that the better RTP performance of PYBr than PYCl is attributed to intersystem crossing (ISC) augmentation induced by the heavy atom effect. Binding to CB[6] through host-guest interactions can simultaneously accelerate the radiative decay process by increasing the transition dipole moment of T1 → S0 (μT1→S0), block the nonradiative decay process, and promote the ISC process, eventually leading to a remarkably boosted RTP. Upon complexation, the conversion of S1 from 1(n, π*) to 1(π, π*) is key to μT1→S0 enhancement; reduced reorganization energies reflect the suppression of the nonradiative decay process by restricting the rotation of rings A and B in organic dyes. In addition, the promoted ISC process is due to the activation of more ISC channels between S1 and high-lying triplet states with large spin-orbital coupling constants and small energy gap. The case of CB[7]-type complexes is much different, because of the extremely large cavity size of CB[7] for encapsulation. This work proposes the mechanism of host-guest interaction-induced RTP enhancement of organic dyes, thus laying a solid foundation for the rational design of advanced RTP materials based on supramolecular assemblies.

Dense arrangement of crown ethers in graphene: novel graphitic carbon oxides with enhanced optoelectronic properties.

Incorporating crown ethers into a graphene lattice presents an efficient means of tuning its properties and expanding its range of potential applications. This study employed density functional theory calculations to introduce a series of novel graphitic carbon oxides through the dense arrangement of crown ethers featuring varying cavity sizes within the graphene structure. These newly developed graphitic carbon oxides exhibit thermodynamic and dynamic stability. They also manifest improved stability relative to previously reported graphene oxides with similar oxygen content. Notably, a robust linear relationship is observed between the cohesive energies and the proportion of oxygen atoms. The electronic properties of these graphitic carbon oxides span a spectrum of characteristics, including semi-metallic, metallic, and semi-conducting behavior. Their calculated band gaps range from 0.11 eV to 4.38 eV. Specifically, our analysis reveals that C6G-1, characterized by its largest crown ether-like nanopore with six oxygen atoms, holds potential as a material for photocatalytic water splitting. Moreover, these materials exhibit anisotropic optical properties, showcasing a significant enhancement in absorption within the infrared and visible regions relative to pristine graphene. Given the successful experimental synthesis of crown ether in graphene, we anticipate that our findings will contribute to the widespread utilization of graphene derivatives in low-dimensional electronic, catalytic, and optical devices.

Evaluation of the binding efficacy of flavonol derivatives on estrogen receptors (ER) with respect to ring B hydroxylation

RationaleFlavonols are a class of flavonoids, consist of two aromatic rings (A and B) connected by a three-carbon bridge, forming a closed pyran ring (C) with a hydroxyl group at position 3. Galangin is a form of flavonols formed with additional hydroxyl groups at ring A positions 5 and 7. The hydroxylation at ring B of galangin may result in resonance and delocalization of electrons and the formation of different derivatives like kaempferol, quercetin, and myricetin. Most of these flavonols have a similarity to 17β-estradiol, the steroid sex hormone which bound to estrogen receptors (ER), a class of nuclear transcription factors involved in the regulation of many complex pathophysiological processes including breast cancer genesis and progression. Various studies have reported that most of the flavonols are antiestrogenic and show anticancer potential, but the mechanisms may be varied like estrogenic, anti-estrogenic, non-estrogenic, and biphasic activities and their mechanisms of action have not been systematically evaluated. AimThe goal of this study is to ascertain the possible interactions of flavonol derivatives to ER with respect to ring B hydroxylation and the unsaturation degree of the C2′=C3′ bond. MethodsThe variations in structure, frontier molecular orbital, molecular electrostatic potential maps, Mullikan charge population of derivatives was determined by Density functional theory (DFT) calculations at B3LYP/6-311G (d,p) level on model molecular systems. A deep insight into these interactions with ER was described by molecular docking studies. Results and discussionResults shows that the flavonol was found more affinity to ERβ and the efficacy was increased with respect to the OH group on ring B. The hydroxyl group at position 3 and 5 in ring A and C are not found much relevant. The site of ERβ is more hydrophilic while binding ligand and the electropositive and electronegative area of the molecule was increased and reaches a maximum for quercetin with the 3 OH group; after that, it found to diminish. Moreover, the reduced cavity size of ERβ and the replacement of LEU384 with polar HIE475 and MET336 increased the polarity and hydrophilicity of the cavity and led to more electrostatic interaction with ligands. ERα is found to be hydrophobic and the polar interaction between the ligands and ERα is less due to open confirmation of the cavity and bulk empty space. The results also emphasize that myricetin and quercetin require less energy to activate while accounting for the values of Gibbs free energy, the electronic configuration of frontier molecular orbitals, and entropy. ConclusionThe hydroxylation on ring B has a significant importance in the chemical reactivity as well as estrogenic activity of flavonol.

Cation induced changes to the structure of cryptophane cages.

Here the monocation complexes of seven anti-cryptophanes are examined with high-resolution ion-mobility mass spectrometry. The relative size of the [cation + cryptophane]+ complexes were compared based on their measured mobilities and derived collisional cross sections. A paradoxical trend of structural contraction was observed for complexes of increasing cation size. Density functional theory confirmed encapsulation occurs for cation = Na+, K+, Rb+, Cs+ and NH4+. However, cation = Li+ preferred oxygen coordination at a linker over encapsulation within the cavity, leading to a slightly larger gas phase structure overall. Protonated cryptophanes yielded much larger collision cross sections via imploded cryptophane structures. Thus, competing physical effects led to the observed non-periodic size trend of the complexes. Trends in complexation from isothermal titration calorimetry and other condensed phase techniques were borne out by the gas phase studies. Further, predicted cavity sizes compared with the gas phase experimental findings reveal more about the encapsulation mechanisms themselves.

Electromigration separation of lithium isotopes with B12C4, B15C5 and B18C6 systems

In the aqueous-organic biphasic electromigration system, the larger cavity size of crown ethers, the weaker binding between crown ethers and Li+, and the lower dissociating voltage of complexes and initial voltage enriching 6Li in the catholyte.

The Effect of Wire Versus Magnetic Seed Localization on Lumpectomy Cavity Size

PurposeTo assess whether an association exists between surgical localization technique and lumpectomy cavity size on radiotherapy planning CT scan. Methods and MaterialsA single-institution retrospective review was conducted of women undergoing breast conserving surgery with wire- or magnetic seed- guided lumpectomy followed by adjuvant radiotherapy from 2018 to 2021. Patients of a surgeon only performing one localization technique or undergoing bracketed localization were excluded. The primary outcome was lumpectomy cavity size on simulation CT. Confounding due to imbalance in patient and tumor factors was addressed with overlap weights derived from a propensity score analysis and used in a weighted multivariable analysis (MVA). Secondary outcomes included positive margins, total pathologic volume, boost delivery, and boost modality. ResultsOf 617 women who received lumpectomy during the study period, 387 were included in final analysis. Tumors of patients undergoing seed localization were more likely unifocal, assessable by ultrasound, and smaller. Seed use rates ranged from 27.7% to 70.7% per surgeon. There was no difference in positive margins (6.4 vs 5.4%, p = 0.79) or second surgeries (9.4 vs 8.1%, p = 0.79) between groups. Close margin rates were similar for DCIS (p = 0.35) and invasive carcinoma (p = 0.97). In unadjusted bivariable analyses, wire localization was associated with larger total pathology volume (p = 0.004) but localization technique showed no association with CT cavity volume (p = 0.15). After adjusting for potentially confounding variables listed in the methods, MVA failed to show an association between localization technique and either CT cavity (p=0.35), or total path volume (p = 0.08). There was no difference in indicated-boost delivery (p= 0.15) or electron boost (p= 0.14) by localization technique. ConclusionsThere was no significant difference in CT cavity size by localization technique, suggesting choice between surgical techniques does not impede radiotherapy boost delivery.

Azo-Linked Porous Polycalix[n]arenes for the Efficient Removal of Organic Micropollutants from Water.

Developing novel porous adsorbents for efficient wastewater treatment is significant to the environment protection. Herein, three porous polycalix[n]arenes (n = 4, 6, and 8) which had varying cavity sizes of the macrocycle (Azo-CX4P, Azo-CX6P, and Azo-CX8P) were prepared under mild conditions and tested for their potential application in water purification. Azo-CX8P with a larger cavity size of the macrocycle outperformed Azo-CX4P and Azo-CX6P in screening studies involving a range of organic micropollutants. It was proved that Azo-CX8P was especially efficient in the removal of cationic dyes because of its high negative surface charge. In terms of the adsorption of Rhodamine B with Azo-CX8P, the pseudo-second-order rate constant reaches 5.025 g·mg-1·min-1 with the maximum adsorption capacity being 1345 mg·g-1. These values are significantly higher compared with those recorded for most adsorbents. In addition, the easily prepared Azo-CX8P can be reused at least six times without a loss of the adsorption efficiency, demonstrating its potential use in water purification.