Diffraction Methods Research Articles

Experimental molecular structures in the gas phase at the upper size limit: The case of Si6Tip6.

Currently, the largest (ramax = 19.9Å) and by far the most complicated (234 atoms, C1 symmetry, 696 independent geometrical parameters, and 27 261 interatomic terms) experimental molecular structure of a cage-type Si6Tip6 (Tip = 2,4,6-iPr3C6H2) isomer has been investigated in the gas phase by the electron diffraction method (Tav = 645K) supplemented with theoretical simulations. A detailed analysis of the current possibilities for experimentally investigating large molecular structures is performed. A series of density functional theory approximations and the role of dispersion interactions have been benchmarked using the obtained data. Based on the refined geometry of Si6Tip6, various quantum-chemical methods have been applied for the investigation of the electronic structure of its Si6 core. In particular, natural bond orbital, quantum theory of atoms in molecules, interacting quantum atoms, fractional occupation number weighted density, and complete active space self-consistent field (CASSCF) methods were utilized. The diradical character of the molecule has been assessed by the UHF and CASSCF approximations. The problem of bonding between the hemispheroidal silicon atoms has been investigated.

Generation of extremely strong accelerating electric field by focusing radially polarized THz pulses with a paraboloid ring

Efficient acceleration of electrically charged particles by focused electromagnetic pulses requires a strong accelerating electric field as well as a sufficiently large interaction region. Single-cycle terahertz pulses are promising candidates for such applications due to their advantageous wavelength and available peak electric field at the MV/cm level. We propose and characterize a focusing optics for a possible electron vacuum accelerator. This consists of a reflaxicon for beam shaping and a ring-like segment of an on-axis parabolic mirror for tight focusing of the radially polarized THz pulse in order to reach a strong accelerating electric field. The electric field distribution in the focal region was determined by the Stratton–Chu vector diffraction method. Semi-analytical and purely analytical formulae were also derived, simplifying the computation procedure. By focusing radially polarized single-cycle terahertz pulses with 3mJ pulse energy, calculations predict accelerating electric field component in the order of 100MV/cm, well suitable for particle acceleration.

A regiospecific fischer indole reaction with 3‐oxo‐24‐nor‐allobetulin

AbstractFirst case of regiospecific formation of indole fused with a triterpene scaffold is observed. Starting from 3‐oxo‐24‐nor‐allobetulin Fischer reaction with phenylhydrazine under the influence of weak acid catalyst led to 3H‐indole (indolenine) 4. This process was accompanied by a change in the configuration of the methyl group at C‐4 that was confirmed by x‐ray diffraction method. On the other hand, 3,2‐indole 5 was synthesized under the influence of strong acid catalyst (using phenylhydrazine hydrochloride in AcOH acid or phenylhydrazine in MeOH with a few drops of HCl).

Synthesis and Characterization of Red Pigment from Acid Regeneration Plant (ARP) By-product Via Rod Milling Process

Iron o xide waste from acid regeneration plants (ARP) is often discarded due to its non-profitability. This research aims to introduce a value-added process to convert iron oxide waste into red pigment via rod milling process. The iron oxide waste collected from ARP was grinded with a rod milling machine at 30 rpm for 24 hours. The ground product was then mixed with industrial-grade red pigment in various ratios. The mixed samples were then rod-milled again into ultra-fine particles. A total of seven samples were prepared, applied onto a canvas and analysed by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) methods. From the analyses, the existence, composition, and orientation of iron oxide were established. The waste-derived red pigments were subsequently subjected to particle size analysis on a scanning electron microscopy (SEM) platform, with results showcasing the efficiency of the rod milling process. Colour-related properties of the samples before and after canvas application were investigated using the L*a*b* system with a chromameter. Empirical outcomes indicated that the a* value plays an important role in determining the redness of the sample. Overall, the a* values obtained were above 15 and gradually increased in accordance to the amount of industrial-grade red pigment added. The oil absorptivity of red pigments was also tested via an oil absorptivity test. Notably, the assay signified that particle size and porosity affect the amount of oil that can be absorbed by the pigment.

Thionitrosyl Complexes of Rhenium and Technetium with PPh3 and Chelating Ligands—Synthesis and Reactivity

In contrast to corresponding nitrosyl compounds, thionitrosyl complexes of rhenium and technetium are rare. Synthetic access to the thionitrosyl core is possible by two main approaches: (i) the treatment of corresponding nitrido complexes with S2Cl2 and (ii) by reaction of halide complexes with trithiazyl chloride. The first synthetic route was applied for the synthesis of novel rhenium and technetium thionitrosyls with the metals in their oxidation states “+1” and “+2”. [MVNCl2(PPh3)2], [MVNCl(PPh3)(LOMe)] and [MVINCl2(LOMe)] (M = Re, Tc; {LOMe}− = (η5-cyclopentadienyl)tris(dimethyl phosphito-P)cobaltate(III)) complexes have been used as starting materials for the synthesis of [ReII(NS)Cl3(PPh3)2] (1), [ReII(NS)Cl3(PPh3)(OPPh3)] (2), [ReII(NS)Cl(PPh3)(LOMe)]+ (4a), [ReII(NS)Cl2(LOMe)] (5a), [TcII(NS)Cl(PPh3)(LOMe)]+ (4b) and [TcII(NS)Cl2(LOMe)] (5b). The triphenylphosphine complex 1 is partially suitable as a precursor for ongoing ligand exchange reactions and has been used for the synthesis of [ReI(NS)(PPh3)(Et2btu)2] (3a) (HEt2btu = N,N-diethyl-N′-benzoyl thiourea) containing two chelating benzoyl thioureato ligands. The novel compounds have been isolated in crystalline form and studied by X-ray diffraction and spectroscopic methods including IR, NMR and EPR spectroscopy and (where possible) mass spectrometry. A comparison of structurally related rhenium and technetium complexes allows for conclusions about similarities and differences in stability, reaction kinetics and redox behavior between these 4d and 5d transition metals.

The effect of silicon dioxide on the structural, thermal and transport properties of an organic ionic plastic crystal (n-C4H9)4NBF4

Composite solid electrolytes based on an organic ionic plastic crystal (n-C4H9)4NBF4 with highly dispersed SiO2 with specific surface area of Ss = 324±10 m2/g have been studied for the first time. By methods of X-ray diffraction and differential scanning calorimetry, it was found that the introduction of SiO2 leads to amorphization of the salt. An unusual size effect was observed in the composites: the temperature of the polymorphic transition of the salt shifted from 67 °C to 60 °C, while the melting point did not change. The 0.15(n-C4H9)4NBF4–0.85SiO2 composite was found to possess the highest electrical conductivity (σ = 2∙10–5 S/cm at 150 °C), which is 1.5 orders of magnitude higher than that of the initial salt. Modelling of the concentration dependences of the electrical conductivity of composites using the mixing equation showed that the reason for the increase in electrical conductivity is the formation of an amorphous layer of salt, the electrical conductivity of which is 3 orders of magnitude higher than that of the crystalline phase (n-C4H9)4NBF4. The obtained results can be used for the design of high-performance composites based on organic ionic plastic crystals for application in electrochemical devices.

Adsorptive removal of phosphate from water with biochar from acacia tree modified with iron and magnesium oxides

A novel biochar (BC) from Acaciatortilis trees pruning waste was synthesized and tested for the removal of phosphate from aqueous solutions. The BC was prepared by calcination at 600 °C and doped with Fe3O4 and MgO by hydrothermal process. The presence of iron and magnesium ions in the modified BC was confirmed by EDS analysis and X-ray diffraction (XRD) methods. Both unmodified and doped BCs were tested for phosphate removal from synthetic 1–500 ppm aqueous solutions. While the unmodified BC did not show any significant removal of phosphate from aqueous solutions, the modified BC almost completely removed phosphate from water. The enhancement in removal efficiency is due to an increase in the overall surface charge and surface area of BC as a result of doping with Fe3O4 and MgO salts. The average porosity and BET surface area corresponding to the plain BC increased by more than 20% from 322 to 394 m2/g after modification by impregnation with iron oxide and magnesium oxide. The modificaiton of BC with Fe3O4 and MgO nanoparticles was observed to increase the point of zero electric charge (PZC) from pH 3.4 (corresponding to plain BC) to pH 5.3 (corresponding to modified BC). The adsorption process was very fast and a phosphate removal value of 82.5% was reached only after 30 min of adsorption, while the removal efficiency after 4 h of adsorption was 97.5%. The rapid removal efficiency in short contact time is attributed to the high surface area of BC and strong bonding between the modified BC surface and PO43− ions. The highest adsorption capacity was observed to correspond to 98.5 mg/g which was achieved at PO43− concentration of 500 ppm and pH 8.5. Moreover, after fitting the adsorption data onto four of the most widely used adsorption isotherm models, the adsorption of PO43− onto BC can be better described by the Langmuir isotherm model.

Response of soil particles around bedrock outcrops to sorting of rock surface flow derived outcrops in a rocky desertification area

Soils around bedrock outcrops, even if they are protected by vegetation to some extent after ecological restoration, are prone to being washed away by rock surface flow (RSF) derived from these outcrops in rocky desertification land. However, the extent of the scouring scale and sorting effect of RSF on the soils around outcrops remains unknown. To solve this problem, a series of soils around bedrock outcrops exposed in sloping farmland (SF, without RSF), abandoned land (AL, 1 year of RSF) and shrub–grassland (SG, 5 years of RSF) were examined by the laser diffraction method in a natural ecological restoration area of rocky desertification, where the duration of the RSF is also the time for ecological restoration. It was found that the RSF had a limited effect on the particle size distribution of the soils, only having a significant scouring effect on the soils at the rock–soil interface within a horizontal distance of 2 cm from the outcrops and an insignificant effect on the soils far away from the outcrops in terms of horizontal distance (10 cm and 20 cm). The particle size distributions of the soil around the outcrops were related to erosion caused by the RSF, but mainly benefited from ecological restoration. Compared with SF, the fine particle content in the soils around the outcrops significantly decreased in AL, but significantly increased in SG. Within a short period (1 year) after natural recovery, the RSF had a reduced effect on the fine particles of the soil around the outcrops; however, this did not occur after a long period (5 years). The results of this study further explain the influence of the RSF on soil erosion and leakage loss in karst areas.

Speckle noise suppression of a reconstructed image in digital holography based on the BM3D improved convolutional neural network

In digital holographic measurement, when light waves pass through inhomogeneous media or surfaces, speckle noise is generated, resulting in random, granular light and dark spots in the hologram, which greatly reduces the image quality. Therefore, in order to improve the image quality of holographic reconstruction, a noise reduction method based on the BM3D improved convolutional neural network (CNN) is proposed in this paper. Firstly, the similarity and important statistical information between blocks can be obtained by using BM3D. Then, the denoising convolutional neural network (DnCNN) is used to learn the relationship between the noise of a large number of samples and the noise image, and further purify the image to retain the details for a better denoising effect. Finally, a reflective off-axis digital holographic optical path system is constructed to collect the holograms of the test samples, and the reconstructed images are obtained by the Fresnel diffraction method to constitute a dataset with the simulated holographic reconstructed images to validate the proposed method in this paper, compared to the other methods, such as DnCNN, convolutional blind denoising network (CBDNet), BM3D, and Wiener filtering. The experimental results of qualitative and quantitative analyses show that the proposed method combines the advantages of traditional algorithms and deep learning, significantly enhances the robustness of the system, optimizes the denoising performance, and preserves the details of the reconstructed image to the greatest extent.

Mechanism of strain-induced magnetic signal change in ferromagnetic materials under weak magnetic environment

Weak magnetic detection based on force-magnetic coupling effect is widely used in nondestructive testing of ferromagnetic materials, but the weak magnetic signals caused by the deformation of ferromagnetic materials under the action of external load show nonlinear changes, and the existing theories can not make a unified conclusion on the mechanism of nonlinear changes of magnetic signals, which limits the further application of weak magnetic detection. In this paper, a microscopic model of ferromagnetic material is established with the strain of the material as the independent variable. Firstly, the reasonableness of the established model is verified by the stress–strain relationship, and the stress concentration phenomenon generated by the change of the microscopic structure of the model is studied in depth by using the XRD diffraction method, so as to put forward the idea of characterizing the macroscopic stress with microscopic dislocations; secondly, the mechanism of the change of the magnetic signals of the ferromagnetic material caused by strain is analyzed by using the atomic magnetic moments and the density of states. The model explains the mechanism of strain-induced magnetic signal change in ferromagnetic materials, and has a guiding role in the further application and promotion of the weak magnetic method.

Evaluation of the Mechanical Strength and Cell Adhesion Capacity of POSS Doped PVA/CMC Hernia Patch.

Peritoneal adhesion typically occurs in applications such as abdominal, pelvic, and vascular surgery. It is necessary to develop a mechanical barrier to prevent adhesion. In this study, a novel biomaterial as a mechanical barrier is developed by combining polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC), doped with polyhedral oligomeric silsesquioxane (POSS) to prevent peritoneal adhesion. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) methods reveal that POSS nanoparticles in the PVA matrix disrupted the intramolecular hydroxyl groups and structure of the crystal region. Electron microscopy (EM) images reveal that high concentrations of POSS (2wt.%) cause irregular clustering in the composite matrix. As the concentration of POSS increases in the matrix, the degradation of the membranes increases, and protein adhesion decreases. In vitro cytotoxicity tests show a toxic effect on cells for PVA/CMC composite membranes, while on the other hand, the addition of POSS increases cell viability. According to the MMT test the POSS decreases cell adhesion of membranes. When comparing the POSS doped membrane to the undoped PVA/CMC membrane, an increase in the total antioxidant level and a decrease in the total oxidant level is observed.

Greening the composite industry: Evaluating Lantana camara Verbenaceae fiber as a promising substitute for lightweight polymer matrix composites

Presently, researchers are engaged in investigations with the aim of developing novel products that exhibit biodegradability and subsequent environmental friendliness. As products, biofiber-based composites are gaining popularity in various industries. Consequently, this investigation successfully identified a unique cellulosic stem fiber from Lantana camara L. (Verbenaceae) plant. As the fiber was unique, sustainable, and abundantly available throughout all seasons, it was selected for the comprehensive characterization investigation to find its potential use as a lightweight bio-based composite material substitute for synthetic fibers. Physiochemical examination revealed that the Lantana camara Verbenaceae fiber had a greater cellulose concentration (61.23±8.42 %) and density (1167±60 kg/m3), measured to be very less compared to synthetic fiber, making a perfect choice for producing lightweight composites with higher strength. The presence of cellulose Iβ and the ordered character of the crystallites were verified by Fourier transform infrared spectroscopy and X-ray diffraction method. Thermogravimetric study showed the maximum degradation temperature of 323 °C, a thermal stability of 242 °C, and a kinetic activation energy of 66.11 kJ/mol. The maximum tensile strength, strain-to-failure percent, and Young’s modulus were observed for 50-mm-length fibers. Detailed analysis of the longitudinal section of the fiber from atomic force microscopy and scanning electron microscopy study revealed that the fiber had a rough surface, which improves the bonding behavior when reinforced. The aforementioned properties showed that L. camara L. fibers are an excellent, greener alternative reinforcement for composite materials, allowing for the cleaner, more sustainable components.

Variations in soil erodibility (K-factor) for the Chernozems depending on the method of texture determination

Soil erodibility (K-factor) is an important parameter in erosion modeling, is one of five factors of the Revised Universal Soil Loss Equation (RUSLE), and generally represents the soil's response to rainfall and run-off erosivity. The erodibility could be determined based on direct measurements of soil properties and mathematical calculations. In this study, the K-factor was calculated based on a formula from RUSLE, proposed by Renard et al. (1997). All input parameters: soil organic carbon (SOC), soil structure, and permeability classes were measured by one method, but particle size distribution – in two ways by sedimentation and laser diffraction methods to assess the impact the K-factor variability and the values of soil erosion rates. The 107 soil samples of Chernozems from Kursk Oblast (Russia) were studied. The texture for the most of samples was classified as silty loam in both analyses. However, the laser diffraction underestimates the clay content by an average of 13.2% compared to the pipette method. The average K-factor estimated based on laser diffraction data was 0.050, and 0.034 t ha h ha−1 MJ−1 mm−1 – sedimentation method. Thus, depending on the method of soil texture analysis, the RUSLE calculated soil loss could underestimated/overstated by 32% (or 4 t ha-1 yr-1 on average in the study site). Therefore, we propose a regression equation-based conversion method of laser diffraction data to sedimentation method data for Chernozems.The Laska-TM laser analyzer measured on ∼ 13% less clay fraction (more on ∼ 8% silt and ∼ 5% fine sand) compared with sedimentation method data.For erosional researchers/modelers it is suggested to state the method of soil texture analysis (based on sedimentation law or laser diffraction) was used for RUSLE K-factor calculations.To convert K-factor values (for Chernozems) calculated and based on data of the sedimentation method to laser sedimentation – it suggested utilize the coefficient 1.47 (0.68 – vice versa).

Structure of Silicon Wafers Planar Surface before and after Rapid Thermal Treatment

Presently it is important to remove mechanically disturbed layer on wafer surface during creation of up-to-date microelectronic products. Rapid thermal treatment with optical pulses of second duration is one of the applicable methods for removing disturbances in crystal lattice emerging after ion implantation. However the crystal structure of mechanically disturbed layer on wafer planar side is still unclear. Researches by transmission electronic method, analysis of diffraction reflection curve and electronic Auger spectroscopy has failed to provide reliable data about the state of crystal lattice in surface layer of at least 30 nm thickness. Hence it was impossible to suggest a model of solid phase recrystallization and to present its mathematical description. The goals of the work were as follows: – identify of silicon crystal lattice state in surface layer of 30 nm thickness before and after rapid thermal treatment by backward reflected electrons diffraction method using raw Si wafers surface; – analysis of contamination element composition on the surface of raw silicon before and after rapid thermal treatment; – model development for solid phase recrystallization of surface disturbed layer after rapid thermal treatment and its mathematical description. Images of back ward reflected electrons diffraction using surface layer of raw silicon wafers' of 30 nm thickness and also the results of the planar surface of raw silicon wafers' cleaning from impurities are provided. Processes reducing the activating energy of mechanically disturbed silicon layer recrystallization process were suggested and its mathematical description was provided. Parameters of rapid thermal treatment mitigating the thermal impact on silicon wafer for recrystallization of mechanically disturbed layer on its planar surface ware defined.

Ganospirones A−G, seven undescribed spiro-meroterpenoids from Ganoderma lucidum and their biological activities

Ganoderma lucidum, a medicinal mushroom with a long history in traditional Chinese medicine, is widely used for chronic diseases. Ganospirones A−G (1–7), seven pairs of undescribed spiro-meroterpenoids, were isolated from the fruiting bodies of G. lucidum. Their structures including absolute configurations were characterized by using NMR spectroscopic data, ECD computational and X-ray diffraction methods. The anti-inflammatory and anti-renal fibrosis activities of the meroterpenoids 1–7 were tested, and the results revealed that (−)-2 and (+)-2 could inhibit iNOS expression in lipopolysaccharide-induced RAW264.7 cells at 20 μM.

Evaluation of multi-walled carbon nanotubes alignment during 3D printing of poly(acrylonitrile-butadiene-styrene) nanocomposite filaments

Nanocomposites incorporated with one-dimensional electrical conductive materials such as carbon nanotubes have been used in many applications in various industries. In this research, the filaments made of poly (acrylonitrile-butadiene-styrene) (ABS) containing 1, 3, and 5 wt% multi-walled carbon nanotubes (MWCNT) were first prepared and then printed in three directions and two printing speeds. The rheological and electrical percolation thresholds were found to take place at 0.32 and 0.96 wt% MWCNT, respectively. Using the Casson plot, it was revealed that the yield stress of the nanocomposites containing 5 wt% MWCNT was 70 times higher than that of the pristine ABS. The results also indicated that the electrical resistance decreased from 17.4 to 6.8 Ω with the increase in printing speed from 4 to 20 mm/s, respectively. The alignment of the nanofillers was examined using X-ray diffraction method. It was found from the azimuth angle that the materials printed at higher printing speed had more orientation, with respect to the director, in comparison with that of printed at lower speed.

Lead Complexes of 3‐(2‐pyridyl)‐5‐(4‐methoxyphenyl)‐1,2,4‐Triazine: Synthesis, Characterization and Application in Organic Light‐Emitting Diodes (OLEDs)

AbstractThree new Pb(II) complexes of 3‐(2‐pyridyl)‐5‐(4‐methoxyphenyl)‐1,2,4‐triazine (PMPT) ligand with different anionic co‐ligands (1: nitrate, 2: perchlorate and 3: isothiocyanate) in 2 : 1 molar ratios of PMPT ligands and lead(II) salts, [Pb(PMPT)2(NO3)2] (1), [Pb(PMPT)2(ClO4)2] (2) and [Pb(PMPT)2(NCS)2] (3) were synthesized and characterized by physicochemical (CHN, FT‐IR and 1H NMR) and single‐crystal X‐ray diffraction methods. By considering the obtained structural parameters, the lead atoms in 1, 2 and 3 have PbN4O4, PbN4O2 and PbN6 environments, respectively, with holodirected (for 1) and hemidirected (for 2 and 3) coordination spheres. We used electro‐optical Pb(II) complexes family as emitting layer to investigate in fabrication of OLEDs. The current–voltage, luminescence‐voltage characteristics and the absorption (Abs) and electroluminescence (EL) properties of the complex have been investigated. The forester radius, quantum yield, and electroluminescence have been studied.

Synthesis, characterization and corrosive resistance of ZnO and ZrO2 coated TiO2 substrate prepared via polymeric method and microwave combustion

The TiO2 substrate coatings containing varied ZnO or ZrO2 nanoparticles were made using the polymeric and microwave combustion methods and then thermally treated at various temperatures. Furthermore, before coating on the substrate, the produced nanoparticles undergo characterization and calcination to optimize the conditions for developing ZnO and ZrO2 phases and track their composition. The X-ray diffraction method (XRD), transmission electron microscopy (TEM), and infrared analysis (IR) are used to characterize the calcined produced nanoparticles. After heat treatment at 1000 °C, the TiO2 substrate is prepared. The produced coated substrate is studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared (IR), apparent porosity, bulk density, chemical corrosive properties and electrochemical measurement in 3.5 % NaCl and 1 M HCl solutions. The corrosion resistance of ZnO or ZrO2-covered TiO2 substrate is ascertained by anticorrosive behaviors, which include weight loss, apparent porosity, corrosion rate, and SEM. The findings showed that 800 °C is the ideal temperature for preparing ZrO2-coated substrate, whereas 1000 °C is the perfect temperature for preparing ZnO-coated substrate. The microstructure reveals surface micro-cracks on the ZrO2-coated TiO2 substrate. Good dispersion, homogeneity, and compaction were noted for the ZnO-coated substrate. Between 14 and 17 % of the ZnO-coated substrate and 20–21 % of the ZrO2-coated substrate, made via polymeric and microwave combustion techniques, had visible porosity when ZnO-coated samples exhibited greater corrosion resistance against NaCl media. In contrast, ZrO2-coated samples had much stronger anticorrosive qualities in HCl media than uncoated and Zn-coated samples. According to the electrochemical results, the ZnO-coated TiO2 synthesized by polymeric technique at 1000 °C showed 99.86 % inhibitory efficiency against NaCl. An inhibitory efficiency of 94.4 % was observed in a ZrO2-coated TiO2 substrate that was produced at 800 °C using a polymeric technique.

The amorphization of crystalline silicon by ball milling

The transformation of crystalline silicon to amorphous silicon during ball milling was quantitatively measured by x-ray diffraction and electrochemical methods. Amorphous silicon was found to form rapidly from the very initial stages of ball milling. Simultaneously, the grain size of the crystalline silicon phase decreased. Under extended milling times it was found that a maximum of 86 % of the silicon became amorphous. Similarly, the grain size of the crystalline silicon phase could not be reduced below 6 nm. This transformation followed an Avrami kinetic model, which is consistent with a system which reaches a steady state. These observations suggest a mechanism in which ball milling generates defects, resulting in silicon amorphization and grain size reduction, where the degree of amorphization is limited in extent because there exists a limiting silicon grain size below which defects are no longer formed.

Characterization Methods to Determine Interpenetrating Polymer Network (IPN) in Hydrogels.

Significant developments have been achieved with the invention of hydrogels. They are effective in many fields such as wastewater treatment, food, agriculture, pharmaceutical applications, and drug delivery. Although hydrogels have been used successfully in these areas, there is a need to make them better for future applications. Interpenetrating polymer networks (IPNs) can be created to make hydrogels more adjustable and suitable for a specific purpose. IPN formation is an innovative approach for polymeric systems. It brings two or more polymer networks together with entanglements. The properties of IPNs are controlled by its chemistry, crosslinking density, and morphology. Therefore, it is necessary to understand characterization methods in order to detect the formation of IPN structure and to develop the properties of hydrogels. In recent studies, IPN structure in hydrogels has been determined via chemical, physical, and mechanical methods such as Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), X-ray diffraction (XRD), and rheology methods. In this paper, these characterization methods will be explained, recent studies will be scrutinized, and the effectiveness of these methods to confirm IPN formation will be evaluated.