Crystal Block Research Articles

Dynamic Covalent Bonds‐Mediated Color‐Switchable Circularly Polarized Luminescence in Helical Assemblies of Achiral Liquid Crystal Block Copolymer Films

Circularly polarized luminescence (CPL) film attracted considerable attention in information storage and encryption, three‐dimensional display, and chiral recognition. However, due to the limited molecular mobility within thin film, achieving a high asymmetry factor and non‐contact modulation of CPL remain challenging. In this work, color‐switchable homochiral CPL films with high luminescence asymmetry factor (glum~0.11) were constructed based on the co‐assembly of a liquid crystal block copolymer (poly (ethylene oxide)‐b‐poly (methyl methacrylate) bearing cyanostilbene group) with axial chiral dinaphthalene diamine derivatives (R/S‐DINBPA). Mechanistic investigation revealed that the efficient stacking of R/S‐DINBPA with cyanostilbene groups and the liquid crystal field provide the driving force for chiral transfer and amplification. The dynamic covalent bonds of the cyanostilbene groups endow the film with chiral fixation ability and enable precise modulation of CPL luminescence bands under UV light irradiation, making it suitable for chiral patterned anti‐counterfeit encryption. This facile strategy provides a general platform for designing intelligent chiroptical materials.

Dynamic Covalent Bonds-Mediated Color-Switchable Circularly Polarized Luminescence in Helical Assemblies of Achiral Liquid Crystal Block Copolymer Films.

Circularly polarized luminescence (CPL) film attracted considerable attention in information storage and encryption, three-dimensional display, and chiral recognition. However, due to the limited molecular mobility within thin film, achieving a high asymmetry factor and non-contact modulation of CPL remain challenging. In this work, color-switchable homochiral CPL films with high luminescence asymmetry factor (glum~0.11) were constructed based on the co-assembly of a liquid crystal block copolymer (poly (ethylene oxide)-b-poly (methyl methacrylate) bearing cyanostilbene group) with axial chiral dinaphthalene diamine derivatives (R/S-DINBPA). Mechanistic investigation revealed that the efficient stacking of R/S-DINBPA with cyanostilbene groups and the liquid crystal field provide the driving force for chiral transfer and amplification. The dynamic covalent bonds of the cyanostilbene groups endow the film with chiral fixation ability and enable precise modulation of CPL luminescence bands under UV light irradiation, making it suitable for chiral patterned anti-counterfeit encryption. This facile strategy provides a general platform for designing intelligent chiroptical materials.

Three Strikingly Different Crystal Habits of Tadalafil: Design, Characterization, Pharmaceutical Performance, and Computational Studies.

The present study aims at improving the physicochemical properties of a widely used drug Tadalafil through crystal habit modification, without changing the polymorphic form. Three distinct types of crystal habits, namely, needle, plate, and block, were obtained under controlled crystallization protocols with optimized solvent compositions. Complete characterization of these three crystal habits was carried out using powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and Fourier transform infrared spectroscopy. Morphological features were studied by optical and scanning electron microscopy. Evaluation of the pharmaceutical performance of different crystal habits reveals significant improvement in compressibility and flow properties for the block-shaped crystals in comparison to the needle- and plate-shaped crystals. Also, a more linear tablet compression behavior was noted for the plate and block morphologies of the API compared to their needle counterpart. In vitro dissolution studies showed distinct release profiles for the same API form with different crystal habits, i.e., needle > plate > block. Insights into crystal growth mechanism and the role of solvents in affording the observed crystal habits are presented based on molecular dynamics simulations of intermolecular interactions with crystal facets, in conjunction with the experimental crystal face indexing of the single crystals of different habits. These observations were further supported by interaction topology analysis and the electrostatic features on different crystal facets.

Enhanced Timing Performance of Dual-Ended PET Detectors for Brain Imaging Using Dual-Finishing Crystal Approach.

This study presents a novel approach to enhancing the timing performance of dual-ended positron emission tomography (PET) detectors for brain imaging by employing a dual-finishing crystal method. The proposed method integrates both polished and unpolished surfaces within the scintillation crystal block to optimize time-of-flight (TOF) and depth-of-interaction (DOI) resolutions. A dual-finishing detector was constructed using an 8 × 8 LGSO array with a 2 mm pitch, and its performance was compared against fully polished and unpolished crystal blocks. The results indicate that the dual-finishing method significantly improves the timing resolution while maintaining good energy and DOI resolutions. Specifically, the timing resolution achieved with the dual-finishing block was superior, measuring 192.0 ± 12.8 ps, compared to 206.3 ± 9.4 ps and 234.8 ± 17.9 ps for polished and unpolished blocks, respectively. This improvement in timing is crucial for high-performance PET systems, particularly in brain imaging applications where high sensitivity and spatial resolution are paramount.

Tunable temperature-responsive photonic ionogels with dual signals output

Photonic ionogels with dual electrical and optical output have been intensively studied. However, tunable temperature-responsive photonic ionogel assembled by thermosensitive nanogels has not been studied yet. Herein, an innovative approach to fabricate photonic ionogels has been developed for smart wearable devices with tunable temperature sensitivity and structural color. Firstly, poly(isopropylacrylamide-r-phenylmaleanilic acid) P(NIPAm-r-NPMA) nanogels self-assemble into photonic crystals in 2-hydroxyethyl acrylate (HEA), water, and the ionic liquid of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate. And then robust photonic ionogels are developed through a polymerization of 2-hydroxyethyl acrylate crosslinked by poly(ethylene glycol) diacrylate (PEGDA). The incorporation of the ionic liquid, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, enhances the mechanical strength of photonic ionogels and tunes the temperature-sensitivity of the ionogels, making them adaptable to various environmental conditions. The findings demonstrate that these ionogels can serve dual functions in smart wearable devices, combining electrical and optical signal outputs due to the conductivity of the ionic liquid and structural color from the nanogel assembly. The resultant photonic ionogels exhibit exceptional substrate adhesion, mechanical stability, and fast resilience. More significantly, the nanogels within these ionogels serve as the building blocks of photonic crystals (PCs) endow with angle-independent coloration and enhance stretchability beyond 200 %, while the stretchability of the ionogles without the nanogels is only about 100 %. Our photonic ionogels with tunable temperature-sensitivity and dual outputs will open an avenue to the development of the innovative smart wearable devices.

Monodomain Liquid Crystal Elastomers Composed of Main‐Chain Type Nematic Polyester Bonded to Rubbery Segments at Both Ends

AbstractMonodomain liquid crystal elastomers (LCEs) are prepared using liquid crystal block copolymers (LCBCPs) comprised of a nematic liquid crystal (NLC) main‐chain polyester linked to cross‐linkable polymethacrylate (PMA) at both ends. LCBCPs at a PMA weight fraction of ≈30% are doped with a tetra‐thiol compound, stretched in one direction, and then illuminated by UV light, yielding LCBCPs that formed microlamellae consisting of alternate stacking crosslinked PMA blocks and NLC polyester blocks. The LC director lay along the stretching direction (SD). Raising the temperature to the NLC isotropization temperature, the crosslinked LCBCP strips fixed at one end contracted reversibly by a factor of 1.2–1.4 along the SD, deforming the microlamellae. The strips fixed at both ends increased the tensile stress to ≈200 kPa while maintaining the microlamellae undeformed. Regardless of strip fixation at one or both ends, the NLC decreased the orientational order. The contraction amounts and the tensile stress of strips are well associated with decreased NLC orientational order.

Preparation of EVAM-g-NSiO2 nanocomposite pour point depressant and its effect on rheological properties of model waxy oil

Modified ethylene-vinyl acetate copolymer (EVAM) and amino-functionalized nano-silica (NSiO2) particles were employed as the base materials for the synthesis of the nanocomposite pour point depressant designated as EVAM-g-NSiO2. This synthesis involved a chemical grafting process within a solution system, followed by a structural characterization. Moreover, combining macro-rheological performance with microscopic structure observation, the influence of the nanocomposite pour point depressant on the rheological properties of the model waxy oil system was investigated. The results indicate that when the mass ratio of NSiO2 to EVAM is 1:100, the prepared EVAM-g-NSiO2 nanocomposite pour point depressant exhibits excellent pour point reduction and viscosity reduction properties. Moreover, the nanocomposite pour point depressant obtained through a chemical grafting reaction demonstrates structural stability (the bonding between the polymer and nanoparticles is stable). The pour points of model waxy oils doped with 500 mg/kg ethylene-vinyl acetate copolymer (EVA), EVAM, and EVAM/SiO2 were reduced from 34 °C to 23, 20, and 21 °C, respectively. After adding the same dosage of EVAM-g-NSiO2 nanocomposite pour point depressant, the pour point of the model wax oil decreased to 12 °C and the viscosity at 32 °C decreased from 2399 to 2396.9 mPa ·s, achieving an impressive viscosity reduction rate of 99.9%. Its performance surpassed that of EVA, EVAM, and EVAM/SiO2. The EVAM-g-NSiO2 dispersed in the oil phase acts as the crystallization nucleus for wax crystals, resulting in a dense structure of wax crystals. The compact wax crystal blocks are difficult to overlap with each other, preventing the formation of a three-dimensional network structure, thereby improving the low-temperature flowability of the model waxy oil.

Cystine Renal Calculi: New Aspects Related to Their Formation and Development.

Background: Crystallization experiments of renal-calculi-forming compounds (calcium oxalate, calcium phosphates, uric acid) are normally performed by monitoring these processes during periods of time similar to the residence of urine inside the kidney. Nevertheless, cystine requires high supersaturation for its crystallization, and most experiments last for longer periods. It must be considered that at high supersaturation, the inhibitors of crystalline development have poor effects. Methods: The induction time of crystallization (ti) of cystine in experimental conditions similar to those of the formation of cystine renal calculi and the effect of different cystine-binding thiol agents was determined through turbidimetric measurements. We also studied the macro- and microstructure of 30 cystine kidney stones through stereoscopic microscopy and scanning electron microscopy. Results: Under the studied conditions, the ti in absence of crystallization inhibitors was 15 min, and the presence of 9 mM of penicillamine, tiopronin, or N-acetylcysteine totally inhibited crystallization, as their effects relate to the formation of complexes with cystine, although N-acetylcysteine also delayed cystine crystalline development and modified cystine crystal morphology. Cystine stones have traditionally been classified as smooth and rough. The study of their structure shows that all of them begin their formation from a few crystals that generate a compact radial structure. Their subsequent growth, depending on the renal cavity where they are located, gives rise to the rough structure in the form of large blocks of cystine crystals or the smooth structure with small crystals. Conclusions: To prevent the development of cystine renal stones, the formation of small crystals must be avoided by reducing urinary cystine supersaturation, with N-acetylcysteine being the most effective among the studied cystine-binding thiol agents. Also, the removal of cystine crystals through increased water intake and physical activity can be a very important preventive measure.

COMPARATIVE ADVANTAGES OF COCONUT SUGAR AGROINDUSTRY: CASE STUDY IN PENGALUSAN VILLAGE, MREBET DISTRICT, PURBALINGGA REGENCY, CENTRAL JAVA, INDONESIA

The objectives of this research were to analyze the financial feasibility and the comparative advantages of the coconut sugar agroindustryin the form of crystal sugar and block sugar. This research is a case study in the centre of coconut sugar industry in Purbalingga Regency, namely Pengalusan Village, Mrebet District which was chosen purposively. Survey method was used in this research by interviewing 40 respondents for coconut crystal sugar agroindustry and 24 respondents of coconut block sugar agroindustry for primary data. This research also used secondary data from Statistical Agency. The analytical method used were the analysis of costs, revenues, profits, and R/C ratio, as well as DRC (Domestic Resource Cost) analysis. The results showed that the R/C ratio analysis for crystal sugar agroindustry was 1.11, and for block sugar agroindustry was 1.04. It means that both agroindustry are financially profitable so that they are feasible to do, though they just receive small profit. The results of the DRC ratio analysis showed that the coconut crystal sugar agroindustry has a comparative advantage so that it can be produced cost-efficiently when using domestic resources. The coconut crystal sugar agroindustry in Pengalusan Village has a comparative advantage with a DRCR (Domestic Resource Cost Ratio) value of 0.505, which means that agroindustry is efficient in allocating domestic resources and is able to save US$ 0.505 of foreign exchange from every US$ 1 unit. Therefore, to meet the demand for coconut sugar, it is better to increase domestic production.

Harnessing plasma-generated reactive species for the synthesis of different phases of molybdenum oxide to study adsorption and photocatalytic activity.

This study employs plasma-liquid interaction technique to synthesize different phases of molybdenum oxide using air and argon as plasma-forming gases. In situ plasma-generated nitrogen species primarily NO3-/NO2- and hydrogen species (H+) facilitate the reduction of the molybdenum precursor anion (Mo7O24-). The reduced Mo species subsequently reacts with reactive oxygen species, forming MoO6 octahedra, which is the building block of a molybdenum oxide crystal. Varied concentrations of NO3-/NO2- and H+ species in air and argon plasma treatment significantly influence the growth process. Air plasma synthesis yields hexagonal molybdenum oxide microrods, which upon calcination changes its phase to orthorhombic 2D layered structure. Moreover, the argon plasma synthesized sample exhibits a mixed phase of hexagonal and orthorhombic molybdenum oxide due to the heavy argon ion bombardment, inducing material porosity and surface oxygen vacancies. The mixed-phase material exhibits superior adsorption and photo-degradation towards cationic dye compared to the other two phases. The higher photocatalytic performance may be responsible for the extended lifetime of the photo-generated charge carriers possessed by the mixed-phase material. Radical scavenging tests have identified holes and hydroxyl radicals as the key reactive species that take part in the photo-degradation process.

Cherenkov Light Emission in Pure Cherenkov Emitters for Prompt Gamma Imaging.

Proton range verification (PRV) in proton therapy by means of prompt-gamma detection is a promising but challenging approach. High count rates, energies ranging between 1 MeV and 7 MeV, and a strong background complicate the detection of such particles. In this work, the Cherenkov light generated by prompt-gammas in the pure Cherenkov emitters TlBr, TlCl and PbF2 was studied. Cherenkov light in these crystals can provide a very fast timing signal with the potential to achieve very high count rates and to discern between prompt-gammas and background signals. Crystals of 1×1 cm2 and thicknesses of 1 cm, 2 cm, 3 cm and 4 cm were simulated. Different photodetector configurations were studied for 2.3 MeV, 4.4 MeV, and 6.1 MeV prompt-gammas. TlCl achieved the greatest number of detected Cherenkov photons for all energies, detector dimensions, and photodetector efficiency modeling. For the highest prompt-gamma energy simulated, TlCl yielded approximately 250 Cherenkov detected photons, using a hypothetical high-performance photodetector. Results show the crystal blocks of 1 cm × 1 cm × 1 cm have greater prompt-gamma detection efficiency per volume and a comparable average number of detected Cherenkov photons per event.

Extending the solid solution range of sodium ferric pyrophosphate: Off‐stoichiometric Na3Fe2.5(P2O7)2 as a novel cathode for sodium‐ion batteries

AbstractIron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework, cost‐effectiveness, and high energy density. However, the understanding of the crystal structure is scarce and only a limited candidates have been reported so far. In this work, we found for the first time that a continuous solid solution, Na4−αFe2+α/2(P2O7)2 (0 ≤ α ≤ 1, could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P2O7 unchanged. In particular, a novel off‐stoichiometric Na3Fe2.5(P2O7)2 is thus proposed, and its structure, energy storage mechanism, and electrochemical performance are extensively investigated to unveil the structure–function relationship. The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g−1, a working voltage of 2.9 V (vs. Na+/Na), the retention of 89.2% of the initial capacity after 500 cycles, and enhanced rate capability of 51 mAh g−1 at a current density of 1600 mA g−1. This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na4−αFe2+α/2(P2O7)2, offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.

Adjustable photovoltaic performance driven by polarization in molecular ferroelectrics

The photovoltaic effect driven by ferroelectric polarization shows great application potential in photovoltaic devices. Two-dimensional (2D) Ruddlesden-Popper perovskite molecular ferroelectric materials, which combine polarization and low band gap properties, occupy a promising position in this field. However, literature reports mostly focus on single crystal blocks, and film devices are rarely reported. In this paper, 2D EA4Pb3Br10 (EA=ethylammonium) molecular ferroelectrics are used as the absorption layers to prepare photovoltaic devices, and the photovoltaic performance of the devices is enhanced by polarization. Dense EA4Pb3Br10 films are prepared by immediately adding antisolvent propylene glycol methyl ether acetate when the spin coating rate reaches the maximum. Surprisingly, the photovoltaic device exhibits significant photovoltaic effects under AM1.5 (100 mW/cm2) illumination with VOC ∼ 1.042 V and JSC ∼ 438.02 μA/cm2, which is much higher than that of ordinary inorganic ferroelectrics. In addition, the photovoltaic performance has been greatly improved by applying an external electric field, reaching to the maximum VOC ∼ 1.087 V and JSC ∼ 489.12 μA/cm2. This indicates the potential application prospects of 2D EA4Pb3Br10 molecular ferroelectric films in photovoltaic devices.

Design study of a novel geometrical arrangement for an in-beam small animal positron emission tomography scanner

Objective. We designed a geometrical solution for a small animal in-beam positron emission tomography (PET) scanner to be used in the project SIRMIO (Small animal proton irradiator for research in molecular image-guided radiation-oncology). The system is based on 56 scintillator blocks of pixelated LYSO crystals. The crystals are arranged providing a pyramidal-step shape to optimize the geometrical coverage in a spherical configuration. Approach. Different arrangements have been simulated and compared in terms of spatial resolution and sensitivity. The chosen setup enables us to reach a good trade-off between a solid angle coverage and sufficient available space for the integration of additional components of the first design prototype of the SIRMIO platform. The possibility of moving the mouse holder inside the PET scanner furthermore allows for achieving the optimum placement of the irradiation area for all the possible tumor positions in the body of the mouse. The work also includes a study of the scintillator material where LYSO and GAGG are compared with a focus on the random coincidence noise due to the natural radioactivity of Lutetium in LYSO, justifying the choice of LYSO for the development of the final system. Main results. The best imaging performance can be achieved with a sub-millimeter spatial resolution and sensitivity of 10% in the center of the scanner, as verified in thorough simulations of point sources. The simulation of realistic irradiation scenarios of proton beams in PMMA targets with/without air gaps indicates the ability of the proposed PET system to detect range shifts down to 0.2 mm. Significance. The presented results support the choice of the identified optimal design for a novel spherical in-beam PET scanner which is currently under commissioning for application to small animal proton and light ion irradiation, and which might find also application, e.g. for biological image-guidance in x-ray irradiation.

Photonic crystal fabric reflects heat to keep wearers warm

Textiles woven into a thin photonic crystal block heat from escaping the body as radiation.

Large‐scale chiral spherulites with controllable circularly polarized luminescence in liquid crystal block copolymers film

AbstractMacroscopic chiral spherulites prepared by hierarchical self‐assembly have attracted considerable attention due to their excellent property as chiroptical materials. However, preparing controllable chiral spherulites in bulk film remains a challenge due to the absent knowledge of the evolution mechanism from the molecule to macroscopic crystal during chiral assembly. In this contribution, chiral macroscopic spherulites were constructed with controllable circularly polarized luminescence (CPL) using enantiomeric tartaric acid and rhodamine B co‐assembled with liquid crystal block copolymers, poly(ethylene oxide)‐b‐poly(methyl methacrylate) bearing azobenzene group side chains. It was found that the chiral liquid crystal field induced by exogenous chiral molecules was closely related to the formation of macroscopic chiral spherulites. Moreover, the transformation of azobenzene cis‐trans isomerization under photo‐thermal endows films with adjustable CPL. This facile strategy provides a platform to design large‐scale chiral structures for chiroptical switching, encryption, and memory storage materials.

Bio-Inspired Hydrogel-Elastomer Actuator with Bidirectional Bending and Dynamic Structural Color.

In nature, some creatures can change their body shapes and surface colors simultaneously to respond to the external environments, which greatly inspired researchers in the development of color-tunable soft actuators. In this work, we present a facile method to prepare a smart hydrogel actuator that can bend bidirectionally and change color simultaneously, just like an octopus. The actuator is fabricated by elastomer/hydrogel bilayer and the hydrogel layer was decorated with thermoresponsive microgels as the photonic crystal blocks. Compared with the previously reported poly(N-isopropylacrylamide) hydrogel-based bilayer hydrogel actuators, which are generally limited to one-directional deformation, the elastomer/hydrogel bilayer actuator prepared in our work exhibits unique bidirectional bending behavior in accordance with the change of structural color. The bending degrees can be changed from -360° to 270° in response to solution temperatures ranging from 20 °C to 60 °C. At the same time, the surface color changes from red to green, and then to blue, covering the full visible light spectrum. The bending direction and degree of the hydrogel actuator can easily be adjusted by tuning the layer thickness ratio of the elastomer/hydrogel or the composition of the hydrogel. The color-tunable hydrogel-elastomer actuator reported in this work can achieve both programmable deformations and color-changing highly resembling the natural actuating behaviors of creatures.

The influence of engineering strain rates on the atomic structure, crack propagation and cavitation formation in Al based metallic glass

To enhance the toughness of metallic glasses (MGs), considerable scientific efforts have been made to investigate the physical mechanism of fracture behavior of MGs in past few years. However, many unresolved puzzles remain about the fracture mechanisms of MGs at present. In this paper, Molecular Dynamics (MD) simulations have been used to investigate the tensile fracture behavior of Al based MGs under nine different Engineering strain rates. Our results show that the higher the Engineering strain rate is, the longer the period of plastic deformation, the shorter the crack length. We have observed that Al amorphous with notch gradually crystallizes during tensile fracture, however, there are differences in the degree of crystallization and atomic arrangement as well as micro-structure in different regions with different Engineering strain rates. In the process of tensile fracture of Al based MGs, the crack propagation mainly along the hexagonal-close-packed (HCP) grain boundaries between face-centered-cubic (FCC) crystal blocks. As the Engineering strain increases, numerous HCP atoms located at grain boundaries gradually migrate into the interior of FCC crystal blocks, the velocity of crack propagation will also increase and finally induce the brittle fracture of Al based MGs. Meanwhile, we effectively demonstrated the existence of HCP and FCC atoms in Al based MGs during tensile deformation by analyzing the bond-orientational order parameters ql. The analysis of thermodynamics (entropy) showed that there is a positive correlation between the Engineering strain rate and the strain of maximum entropy when the Engineering strain rate exceeds 0.002 ps−1. The formation of cavitation ahead of crack could be attributed to the migrate of atoms from the higher entropy cavity region to the lower entropy crystallization region. This study enriches the traditional tensile deformation theories and provides a new understanding for the physical origins of cavitation in the crack tip of MGs.

Two novel quinoline-decorated half-salamo-type Co(II) complexes: Synthesis, crystal structure, Hirshfeld surface analysis, DFT calculation and fluorescence properties

Self-assembly through a quinoline-decorated N3O donor half-salamo-type tetradentate ligand HL and coordinative preference of Co(II) ion, two novel Co(II) complexes [Co(L)Cl] (1) and [Co(L)(NCS)] (2) were synthesized and characterized. X-ray crystallography revealed that both complexes 1 and 2 have similar mononuclear structure, in which the five-coordinated Co(II) atoms are not only surrounded by the N3O cavity of the deprotonated ligand (L)− unit, but also coordinated with different Cl− and NCS− anions. For the involvement of different anions, the crystal structures of the two complexes exhibit intermolecular CH···Cl and CH···S hydrogen interactions in building supramolecular assemblies, respectively. The two complexes are stabilized by CH···O, CH···N, CH···C, CH···S bonds and CH···π, π···π interactions. The spectral properties of the complexes were investigated through UV–Vis and fluorescence spectroscopy. In addition, the detailed analyses of Hirshfeld surfaces and fingerprint plots provide the basis of the intermolecular interactions in building crystal blocks.

Establishing the optimal condition for nutrient recovery from domestic wastewater using the freeze concentration method

Abstract The freezing concentration method is one of the potential techniques for recovering nutrients from wastewater. In this study, the method of freeze concentration was studied to establish its optimal conditions in recovering nitrate-nitrogen and phosphate nutrients from domestic wastewater. Water in the form of an ice crystal block is produced and leaves behind a solution with a higher concentration. The effects of coolant temperature from −10 to −80 °C, freezing time from 1 to 8 h, and energy consumption on nutrient recovery were investigated. The optimal conditions were found at a coolant temperature of −20 °C, freezing time of 7 h, and energy consumption of 0.197 kWh/L that resulted in the highest nitrate-nitrogen and phosphate nutrient recovery values of 1.114 and 4.667, respectively, at the inlet of anaerobic digester 1; 1.325 and 4.975, respectively, at the outlet of anaerobic digester 1; 1.099 and 4.859, respectively, at the inlet of anaerobic digester 2; 1.132 and 4.755, respectively, at the outlet of anaerobic digester 2; and for gravel filter at the outlet the values were 1.111 and 4.861, respectively. The recovered nutrients can be used as biofertilizers.