Ammonium Chloride Solution Research Articles

Stress Corrosion Cracking of 316L Stainless Steel in Concentrated Ammonium Chloride Solution with Very Low Dissolved Oxygen Levels

ABSTRACT Slow strain rate testing has been used to investigate the susceptibility of 316L stainless steel to SCC in high chloride and low dissolved oxygen brines. Tests have been carried out for various temperatures and ammonium chloride (NH4Cl) concentrations. The susceptibility to SCC was assessed in terms of ductility loss, detailed fractography and cross-sectional inspections to identify the damage mechanisms. It is challenging to maintain long-term SCC experiments with very low DO levels. In this work, we showed that 3 hours of sparging with high purity nitrogen at a flow rate of 0.2 L/min was sufficient to reduce the DO in a 0.6 L test solution to ~ 10 ppb. However, over the full test duration of 7 or 8 days with continuous nitrogen purging of the solution, the mean and maximum DO values were 17.4 and 34.4 ppb in 40 wt.% NH4Cl, and 16.5 ppb and 41.8 ppb in 30 wt.% NH4Cl solutions at 95 °C. For 316L stainless steel at open circuit in ≥ 30 wt % (i.e. 6.1M) ammonium chloride solutions with these very low DO levels, pitting corrosion was not seen at 60 °C, became evident at 80 °C and was severe at 95 °C and above, while SCC was not seen at 60 or 80 °C, was possibly initiating at 80 °C without propagating significantly, and was severe at 95 °C.

Limited Effectiveness of Conventional Sanitisers and Hot Water as an Alternative for Preventing the Spread of Ceratocystis fimbriata via Tools

ABSTRACTWounds are crucial entry points for infection by Ceratocystis spp. Consequently, tool disinfestation is a crucial practice in disease management, especially for host crops such as kiwifruit, teak, mango and cacao, which require cultural practices that cause wounds, such as pruning and thinning. Although conventional sanitisers, such as sodium hypochlorite, are recommended for controlling Ceratocystis wilt, their effectiveness on tools lacks scientific validation. Additionally, there is no consensus on the optimal exposure time and active ingredient concentration for effective disinfestation. Our study confirmed that C. fimbriata can be mechanically spread from diseased to healthy plants via pruning shears. We then evaluated the effectiveness of conventional sanitisers and hot water (80°C) for the disinfestation of pruning shears and scalpels on kiwifruit plants. Firstly, in vitro comparisons revealed that ammonium chloride solution and hot water effectively inhibited the mycelial growth of the fungus. Furthermore, immersing tools in hot water (80°C for 15 s) was the only effective disinfestation method, while sodium hypochlorite and other conventional sanitisers failed to eliminate the pathogen at the dosages and exposure times tested. Based on these findings, a revision of disinfestation protocols for Ceratocystis wilt is recommended, with further studies needed to evaluate different concentrations and exposure times. In conclusion, hot water is an effective alternative to conventional sanitisers in preventing the mechanical spread of the pathogen.

Comparison between the degradation effect induced by low pressure air plasma and at atmospheric pressure of diethyl (3h-1-ethoxy-3-phenoxazinylidene) ammonium chloride solution

Comparison between the degradation effect induced by low pressure air plasma and at atmospheric pressure of diethyl (3h-1-ethoxy-3-phenoxazinylidene) ammonium chloride solution

Study on Interlayer Interface Deterioration of Double-Block Ballastless Track in Humid and Hot Environments Based on Acoustic Emission Technique

The deterioration of the interlayer interface of a double-block ballastless track is affected by the environmental temperature and moisture conditions, which will have a negative effect on its service life. Composite specimens with interlayer interfaces of double-block ballastless track were fabricated and deteriorated by an accelerated method, i.e., immersed in saturated ammonium chloride solution with various temperatures for different times. Then, the deterioration condition and mechanical properties of the composite specimens were investigated experimentally by a universal material testing machine and acoustic emission technique. The automatic sensor test (AST) method is capable of assessing the deterioration condition of the interlayer interface based on the relative wave velocity. The deterioration depth of the interlayer interface tends to increase with increasing solution temperature and immersion time. Both the solution temperature and immersion time have a negative impact on the splitting tensile strength and direct shear strength. A linear relation is found between the splitting tensile strength (direct shear strength) and the cumulative AE energy released at the fracture moment. The damage factor defined by the cumulative AE energy for most composite specimens is no greater than 0.2 before they are going to be fractured but increases sharply to 1.0 at the fracture moment.

Recovery of zinc and lead by simultaneously leaching from lead slag fuming dust with ammonium chloride solution

Recovery of zinc and lead by simultaneously leaching from lead slag fuming dust with ammonium chloride solution

Study on the Effect of Cations on Morphology in the Preparation of Vaterite Calcium Carbonate from Dolomite

AbstractIn this paper, the effect of trace components in dolomite on the morphology of vaterite calcium carbonate is studied in the CaCl2‐NH3‐CO2 system, with a focus on the effect of cations (Mg2+, Fe3+, Si4+, and Al3+) in the solution. Ca2+, NH4+, Mg2+, Fe3+, Si4+, and Al3+ in the digestion solution are proportionally prepared into a solution by analyzing the calcium rich digestion solution which is obtained by digesting dolomite with ammonium chloride solution. Under the optimal conditions, NH3 is introduced at a rate of 0.5 L min−1 for 1 h, CO2 is introduced at a rate of 0.5 L min−1 for 1 h and rotation speed of 500 r min−1 to prepare the vaterite calcium carbonate. The results show that the addition of Mg2+, Fe3+, Si4+, and Al3+ can promote the growth of vaterite calcium carbonate. Among them, adding Mg2+ and Si4+ can promote the dispersion of vaterite, Fe3+ and Al3+ can cause agglomeration of vaterite. Material Studio software is used to predict the crystal morphology of vaterite calcium carbonate under ideal conditions, and the calculation results are basically consistent with the experimental results.

Experimental study on the drag reduction of underwater vehicles by drag-reducing agents injection

Underwater vehicles consume much energy to overcome flow resistance; therefore, reducing drag is essential to enhancing its performance. This paper proposes a drag reduction method for underwater vehicles by injecting drag-reducing agents into the turbulent boundary layer of the underwater vehicles and experimentally evaluates its performance based on the scaled suboff model. To this end, the unique injection structure and location are carefully designed to ensure the adherence of the drag-reducing solution on the wall. The polyethyleneoxide (PEO) and ceytltrimethyl ammonium chloride (CTAC) solutions are chosen as the drag-reducing agents. The effects of concentrations, flow rates, and mainstream Reynolds numbers (Re) on the drag reduction performance are investigated by measuring the total drag resistance of the scaled suboff model under different conditions. The results demonstrate that this heterogeneous drag-reducing solution injection strategy performs well in terms of drag reduction for the suboff model. The specially designed injection structure can uniformly distribute the drag-reducing solution to the near-wall region of the suboff model. Under certain conditions, both PEO and CTAC solutions can significantly reduce the total drag resistance and have an optimal concentration at different Re. At their optimal concentrations, the drag reduction of the total resistance can achieve about 59.38% and 48.31% for PEO and CTAC solutions, respectively, at Re = 2.7 × 104. However, with the current design, the drag reduction decreases with the increase of Re due to the difficulty of the drag-reducing agent wrapping around the suboff model effectively. Further work is still necessary to improve the design and the location of the injection structure so that it can adapt to high-Re cases.

Multifunctional composite phase change material with electrostatic self-assembly structure based on carboxylated multi-walled carbon nanotubes

The need for improved thermal regulation in electronic devices and solar thermal energy storage, prompted by the energy crisis, has expedited the advancement of phase change materials (PCMs). Carboxylated multi-walled carbon nanotubes (MWCNT-COOH) were produced by introducing carboxyl functional groups onto MWCNTs utilizing a concentrated acid treatment. The novel composite was engineered through an electrostatic self-assembly process between the negatively charged MWCNT-COOH and the positively charged Poly dimethyl diallyl ammonium chloride (PDDA) solution, filling the structure with the PCM polyethylene glycol (PEG) and incorporating the (magnesium hydrate) Mg(OH)2 to enhance the material's flame resistance at high temperatures. The thermal conductivity of the obtained composites improved significantly from 0.25 W/m·K to 1.183 W/m·K, while maintaining an enthalpy of phase transition of phase change of 135.1 J/g. Owing to the capillary effect of the closely packed MWCNT-COOH tubular structure, the composite material exhibited excellent high-temperature shape retention ability. Additionally, the composite demonstrated high absorption with an absorbance reaching 1.18 L/(g·cm) and composite materials can convert up to 86.8 % of light energy into heat energy.

Study on solubility and solvation thermodynamics for the advancement of biorelevant activities of l-isoleucine and l-serine in aqueous ammonium chloride solutions in the temperature range of 288.15–308.15 K

This study investigated the dissolution behavior of l-isoleucine and l-serine in an aqueous salt solution (ammonium chloride), examining how variations in temperature and electrolyte concentration affect their solubility. We conducted careful experiments and used mathematical calculations to explore interactions at a molecular level. We observed that the structure of these amino acids and salt concentration in the aqueous medium influence their interactions, which affects dissolution. In the presence of electrolytes, l-isoleucine demonstrated a salting-out effect whereas l-serine showed a salting-in effect. This work examines the solute–solvent interactions of these solutes in aqueous ammonium chloride solutions. l-isoleucine exhibits a nonspontaneous reaction with increasing salt concentrations whereas l-serine shows spontaneous behavior. Gibbs free energy analysis revealed greater stability of l-serine. The pH and conductance measurements showed how these factors influence solution properties. This insight helps us comprehend the nature and behavior of these molecules in different situations, which could be helpful in drug formulation or protein purification in the future.

Preparation of high‐performance polymer sensitive membrane for rapid and sensitive detection of ammonium ions in aqueous solution

AbstractPolymer sensitive membrane is a key component of the ammonium ion selective electrode (ISE). Developing a high‐performance ammonium ion polymer sensitive membrane can promote production and application of the electrode, reducing costs and simplifying ammonia nitrogen detection. In this study, we modified the surface of the ammonium ion selective membrane and synthesized a low‐cost antimicrobial material by anchoring the broad‐spectrum antimicrobial agent, silver nanoparticles (AgNPs), on the surface of two‐dimensional transition metal car‐ bides (Ti3C2Tx MXene). This material can be used as a carrier to avoid the release of AgNPs. The inorganic antimicrobial agent AgNPs@MXene was adhered to the surface of the ammonium ion‐selective membrane by polydopamine, forming an antimicrobial coating. The modified ammonium ion‐selective electrode had a rapid response time of 12 s, with an average response time of 12.4 s. After repeated tests, a lower detection limit of 5.89 × 10−7 (10−6.23) mol/L was achieved in ammonium chloride solution. These results indicate that the ammonium ion monitoring electrode we prepared can effectively monitor ammonia nitrogen concentration in sewage and wastewater over a long period of time. This also enhances the service life of the ammonium ISE and reduces maintenance costs for the sensor.

Increasing the Wear and Corrosion Resistance of a CP-Ti Surface by Plasma Electrolytic Borocarburizing and Polishing

The paper examines the possibility of increasing the wear and corrosion resistance of a CP-Ti surface by duplex plasma electrolytic treatment (borocarburizing and polishing). The structure and composition of diffusion layers, their microhardness, surface morphology and roughness, wear resistance during dry friction and corrosion resistance in Ringer’s solution were studied. The formation of a surface-hardened layer up to 200 μm thick with a microhardness of up to 950 HV, including carbides and a solid solution of boron and carbon, is shown. Subsequent polishing makes it possible to reduce surface roughness and remove weak areas of the porous oxide layer, which are formed during high-temperature oxidation in aqueous electrolyte vapor during borocarburizing. Changing the morphology and structural-phase composition of the CP-Ti surface helps reduce weight wear by a factor of three (the mode of frictional interaction changes from microcutting to oxidative wear) and corrosion current density by a factor of four after borocarburizing in a solution of boric acid, glycerin and ammonium chloride at 950 °C for 5 min and subsequent polishing in an ammonium fluoride solution at a voltage of 250 V for 3 min.

Leaching Thermodynamics of Low-Grade Copper Oxide Ore from [(NH4)2SO4]-NH3-H2O Solution.

This paper describes a highly alkaline low-grade copper oxide ore. Copper can be selectively leached out while other metals are retained. A thermodynamic model of the CuO-(NH4)2SO4-NH3-H2O system was established for the leaching of tenorite (CuO) under conditions of mass and charge conservation. MATLAB's fitting functions, along with the diff and solve functions, were used to calculate the optimal ammonia concentration and total copper ion concentration of tenorite under different ammonium sulfate concentrations. The effects of various ammonia-ammonium salt solutions (ammonium sulfate, ammonium carbonate, ammonium chloride) on the copper leaching rate were investigated. Results show that under the conditions of an ammonia concentration of 1.2 mol/L, an ammonia-ammonium ratio of 2:1, a liquid-solid ratio of 3:1, a temperature of 25 °C, and a leaching time of 4 h, the copper leaching rate from the ammonium sulfate and ammonium chloride solutions reaches 70%, which is slightly higher than that of ammonium carbonate. Therefore, an ammonia-ammonium sulfate system is selected for leaching low-grade copper oxide due to its lower corrosion to equipment compared to the chlorination system. The impact of this study on industrial applications includes the potential to find more sustainable and cost-effective methods for resource recovery. The industry can reduce its dependence on resources and mitigate its environmental impact. Readers engaged in low-grade oxidized copper research will benefit from this study.

Expermintal Research of Electrochemical Behaviour of Zinc in Ammonium Chloride Solutions

A present study was investigated “Experimental Research of Electrochemical Behaviour of Zinc in Ammonium Chloride Solutions.” The study was investigated by the electrochemical corrosion of sine is a problem of high significance both in the fundamental and applied fields of electrochemistry. Hence investigations were undertaken to study the corrosion of zinc in storage systems, the electrodeposition and characterisation of sine and the electrodeposition and characterisation of Siti nickel alloy. Results was shows that Potential-pH diagram for zinc in ZnClg/ NH₄Cl electrolyte, as used in Laclanche’s cell. When the surface composition of polished zinc. A freshly polished Zn surface was immersed in 0.5M NH₄Cl for 45 seconds and then analysed for energy measurements by ESCA. The composition of the modified zinc surface is summarised in table-1, When the binding energy was scanned in a narrow range of 1021 to 1010 eV, the participation of Zn 2PI electrons in the bond formation was confirmed. The investigations on the zinc- NH₄Cl system were hence carried out with the following specific objectives: IC4 find out the structure and nature of the species formed un the surface of sine when introduced in NH₄Cl solutions.

Impact of Ground Granulated Blast Furnace Slag on Calcium Leaching of Low-Heat Portland Cement Paste.

Low-heat Portland cement and ground granulated blast furnace slag are widely used for the preparation of hydraulic concrete. Nevertheless, the effect and mechanism of corrosion on low-heat Portland cement paste mixed with ground granulated blast furnace slag need to be further explored. This paper investigated the impact of ground granulated blast furnace slag on the calcium leaching of low-heat Portland cement paste by evaluating its mass loss, porosity, leaching depth, compressive strength, and Vickers hardness, and comparing it with the leaching performance of ordinary Portland cement paste. Furthermore, the phase composition and morphology of low-heat Portland cement paste containing ground granulated blast furnace slag were analyzed by X-ray diffraction, mercury intrusion porosimetry, and scanning electron microscopy. The results indicate that, after 180 days of soaking in ammonium chloride solution, the mass loss rate, growth rate of porosity, leaching depth, and compressive strength loss rate of low-heat Portland cement paste were 8.0%, 43.6%, 9.1 mm, and 27.7%, respectively, while those of ordinary Portland cement paste were 7.4%, 37.8%, 8.4 mm, and 30.1%, indicating that low-heat Portland cement paste is slightly more damaging than ordinary Portland cement. The addition of ground granulated blast furnace slag could significantly improve the leaching resistance of low-heat Portland cement. For instance, after adding 20% ground granulated blast furnace slag, the above test values were 2.4%, 28.5%, 5.6 mm, and 20.8%, respectively. The reason for this is that ground granulated blast furnace slag has the potential to reduce the porosity of low-heat Portland cement paste, and it can also undergo the secondary hydration reaction with its hydration product Ca(OH)2 to enhance the paste structure. Considering the cost performance, the suitable dosage of low-heat Portland cement paste for satisfactory leaching resistance is about 20%.

Wall-scaling prevention in cryogenic external cooler of ammonium chloride solution by liquid-solid fluidization

A double-tube cooler with liquid-solid circulating fluidization operation and corresponding parameter measuring system are developed to avoid fouling of inner walls of heat exchange tubes in a cryogenic temperature external cooler of ammonium chloride solution in soda ash production. Wall-scaling prevention performance of the cooling process is experimentally evaluated using convection and overall coefficients, enhancement factor, wall temperature and fouling resistance. Effects of different volume fractions of added particles, particle size, superficial liquid velocity, and cooling medium temperature on heat transfer are examined. Under present conditions, convection coefficient of liquid-solid flow inside the tube of external cooler is higher than that of the liquid phase flow, increased by 0.7–2.8 times, enhancing cooling performance obviously. Convection coefficient initially increases and then decreases as the volume fraction of added particles increases, reaching its maximum value at a volume fraction of 2.0%. The wall-scaling prevention effect of glass beads mainly depends on the volume fraction of added particles; optimal anti-fouling effects are achieved when adding particles at a volume fraction of 2.0%, regardless of changes in superficial liquid velocity or cooling medium temperature. This study lays a foundation for industrial applications of this new technique of fluidized bed external coolers.

The improvement on calcium leaching resistance of high SCMs content cement in ammonium chloride solution using particle gradation technique

Particle gradations of Portland cement (PC), fly ash (FA), and blast furnace slag (BFS) were optimized to improve the calcium leaching resistance of blended cement with high contents (up to 70%)of supplementary cementitious materials (SCMs). The results showed that optimized blended cement showed refined initial pore volume distribution, reduced portlandite (CH) content, finer CH macrocrystals and enhanced stability of C-(A)-S-H gel. Consequently, it displayed exceptional calcium leaching resistance with reduced losses in mechanical performance, mass and pore degradation after calcium leaching. Blended cement with 30% PC (D50 = 14.46 μm), 30% FA (D50 = 10.94 μm), 20% BFS (D50 = 10.52 μm), 13% BFS (D50 = 5.31 μm) and 7% BFS (D50 = 4.71 μm), showing compressive strength retention rate of 79.05% and mass loss rate of 1.64%, was suggested as viable choice for calcium leaching resistant concrete.

Modification of Natural Zeolite from Klaten, Indonesia Using Ammonium Chloride by Ion-Exchange and Its Application as Catalyst in Ethanol Dehydration to Produce Diethyl Ether

Modification of a natural zeolite from Klaten, Indonesia, as a catalyst in the dehydration of ethanol to produce diethyl ether (DEE) has been conducted. Raw Klaten natural zeolite (ZA) was modified using 1 and 2 M of an ammonium chloride solution for 24 h while stirring for 18 h, then calcined at 500 °C for 5 h under N2 gas flow produced HZA1 and HZA2 catalyst, respectively. The catalysts were characterized using XRD, BET surface area, SEM-EDX, XRF, FTIR and gravimetric acidity test using ammonia-based vapor. The dehydration process was conducted under variations of temperature (200, 250, and 300 °C) and catalyst mass of 0.1, 0.2, and 0.4 g for 20 mL of 96% ethanol. The HZA1 catalyst produced the highest yield of DEE (2.41%) at 250 °C and 0.1 g catalyst. This catalyst showed needle-like of 66.22 nm crystal size, consisting of 32.57% mordenite, the highest surface area (48.32 m2/g), crystallinity (32.93%) and Brønsted acid sites (2.75 mmol/g), the lowest pore diameter (1.77 nm) and Si/Al mol ratio (4.03). The HZA1 catalyst can be used repetitively and produced DEE yield at the second and third runs (2.40 and 2.61%).

MINERAL COMPOSITION OF MANDIBULAR BONE TISSUE IN SIMULATED PERIODONTITIS DURING METABOLIC ACIDOSIS

Destructive changes in the mandibular cancellous bone tissue determine the severity of periodontal diseases and affect their treatment outcomes. The imbalance between macro- and microelements leads to structural and functional changes in the spongy bone tissue of the lower jaw, and when being combined with the inflammatory process in the soft tissues of the periodontium leads to the tooth loss. Mineral elements deposited in the bones are included in the body buffer systems and are able to influence the metabolic processes of the macroorganism by mobilizing them into the bloodstream.
 The aim of the study is to carry out a comparative analysis of mineral element concentrations in the bone tissue of the alveolar process of the lower jaw in rats with experimentally induced periodontitis under conditions of simulated metabolic disorders and following pharmacotherapeutic correction.
 Materials and methods. The reseach was conducted on 80 white outbred sexually mature male rats aged 2-4 months and weighing 120-200 g. The animals were divided into 5 groups (16 in each): two control groups representing NC (negative control) and PC (conditionally positive control) and three experimental groups: I Group, II Group, III Group. The NC group consisted of animals kept on a standard vivarium diet throughout the experiment. The animals of PC, I – III Groups were exposed to peridontitis simulation: the rats received 0.04% solution of ammonium chloride (NH4Cl) per os within 30 days. Animals in group III (experimental periodontitis) received intramuscular injections of 5% meldonium dihydrate solution in a dose of 0.2 mg/kg of body weight. The rats in group IV (periodontitis treatment) received "Calcium glycerophosphate" (a first-generation calcium supplement) in a dose of 133 mg/kg. Group V (combination treatment) received both the meldonium dihydrate solution and calcium glycerophosphate in the same respective doses. Tissue levels of zinc, magnesium, strontium, calcium, sodium, potassium, phosphorus, and iron were measured using atomic absorption (zinc, magnesium), atomic emission (strontium, calcium, sodium, potassium), and photometric (phosphorus, iron) methods.
 Results. The change in the amount of elements in the mandibular cancellous bone tissue reveals irregularity and different mechanisms over the course of the mineralization process, depending on the chosen means of correction. The findings obtained suggest that the corrective treatments (meldonium dihydrate, calcium glycerophosphate, or their combination) promoted gradual bone density improvement through the accumulation of studied elements in the rat mandible. This indicates potential reversibility of pathological changes at this experimental stage.
 Conclusions. The cancellous part of the mandible in rats appears to be a dynamic system, responding actively to both detrimental factors and corrective interventions by altering the content and proportions of macro- and microelements.

Study on the calcium dissolution of self-compacting recycled concrete

Considering the effects of the replacement rate of recycled coarse aggregate (RCA), content of fly ash (FA), and solution temperature, the accelerated calcium dissolution test of self-compacting recycled concrete (SCRC) was simulated by using ammonium chloride solution. The results show that the physical properties (the mass loss ratio and the dissolution depth) and the strength degradation of SCRC increase with the increase of the replacement rate of RCA and solution temperature. With the increasing content of FA, the physical properties decrease approximately linearly, while the strength degradation first decreases and then increases. For the SCRC with 50% RCA and a dissolution age of 56 days, the dissolution depth of SCRC with the FA contents of 10%, 20%, and 30% decreased by 3.85%, 10.00%, and 15.56% respectively compared with that of SCRC without FA, and the degradation rate of compressive strength also decreased by 11.60%, 25.91%, and 15.01%, respectively. The peak stress of the stress-strain curve of SCRC under axial compression is negatively correlated with the dissolution age, replacement rate of RCA, and solution temperature, while the peak strain is positively correlated with these variables. When the dissolution age is more than 28 days, the calcium silicate hydrate (C-S-H) gels produced by low-volume (10%, 20%) FA after complete hydration lead to an increase in peak stress and a decrease in peak strain of SCRC, while high-volume (30%) FA has the opposite effect due to incomplete hydration. Finally, the performance degradation model of SCRC under calcium dissolution was established.

Pore evolution in extrusion-based 3D printed cementitious materials due to calcium leaching

Extrusion-based 3D printed cementitious materials (3DPC) require specific parameters to be met that will substantially impact printed part durability, particularly when exposed to aggressive external conditions. Due to the specificity of the spatial distribution of the pores, 3DPC are reported to exhibit performance anisotropy compared to cast materials. A fundamental understanding of the discrepancy in the pore evolution between the printing direction, lateral direction, and top direction is essential for calcium leaching from 3DPC in aggressive water. This research investigates pore structure evolution in 3DPC with the three directions in a 6 mol/L ammonium chloride solution. The leaching depths of the samples in the three directions were tested and compared. In addition, their porosity, maximum, median, and average pore diameters, pore size distribution, and pore morphology are investigated using optical microscope (OM) and mercury intrusion porosimetry (MIP) analysis. Significant differences were found between the leaching depths in the different directions of the 3DPC. Samples leached in the top direction show less leaching depth than in the other two directions, indicating the anisotropic nature of 3DPC. This was attributed to the different pore structures of the sample in the top direction compared to the other directions, as confirmed by OM and MIP analysis. Furthermore, the pore morphology is more irregular and elongated in the printing and lateral directions than in the top direction. In turn, the calcium leaching increases the porosity and coarsens the pore structure of 3DPC. The results of this study can be used as a reference for the application of 3DPC in aggressive water environments.