Thermal Hysteresis and Bursting Rate in Sucrose Solutions with Antifreeze Proteins

Antifreeze proteins (AFPs) modify the ice shape and inhibit further growth leading to thermal hysteresis (TH). Numerous studies have been performed with the addtition of AFPs to preserve frozen products but the influence of sucrose on the effects of AFPs has not been investigated as of yet. Therefore, the TH activities of type I antifreeze protein (AFP I) and antifreeze glycoprotein (AFGP) were measured as a function of concentration, type of AFPs, and also sucrose concentration. The results showed that the TH values rose with increase in concentration of AFPs and sucrose concentration. The crystals experienced shape modification and grew in the c-axis direction in the presence of both AFPs. The bursting rate of crystals changed depending on both the concentrations of AFPs and sucrose.     

Encapsulation of glucose oxidase (GOD) in polyelectrolyte complexes of chitosan–carrageenan

The purpose of this study was to investigate the potential ability of carrageenan (κ-, ι-, λ-) and chitosan to form a controlled-release system for glucose oxidase (GOD). GOD was encapsulated in chitosan/carrageenan complexes at charge ratios (+/?) of 3 and 5 in mildly acidic solution. The encapsulation efficiency and activity of the loaded GOD were investigated. Among the different complexes prepared, chitosan/κ-carrageenan complex showed high encapsulation efficiencies of 79% and 62.5% at charge ratios of 3 and 5, respectively. The order of encapsulation efficiency decreases toward chitosan/λ-carrageenan complex (κ > ι > λ). After treatment with chitosanase and pepsin solutions, the activity of encapsulated glucose oxidase (GOD) was preserved for all complexes. The chitosan/κ-carrageenan complex was able to preserve 80.2% of GOD activity in pH 1.2 solution, 73.3% in chitosanase solution and 66.4% in pepsin solution. Controlled release of GOD was observed when the complexes were treated with different physiological and enzyme solutions; the complex of chitosan/κ-carrageenan had the lowest release rate of GOD. The simple preparation of chitosan/carrageenan complexes and their ability to protect protein integrity under acidic conditions make them a promising drug delivery system for the oral administration of peptides and proteins.     

Modulation in Aggregation Behavior of Cationic Surfactant in Presence of Fluoroquinolone Drug: A Physicochemical Approach

Measurements of density, speed of sound, conductivity, and fluorescence spectroscopy have been carried out to study the interactions between cationic surfactant cetyltrimethylammonium bromide in an aqueous solution of the fluoroquinolone drug at different concentrations and temperatures. Volumetric and compressibility parameters, such as apparent molar volumes ( V _φ ), isentropic compressibility ( κ _s ), and apparent molar isentropic compressibility (κ _{φ, s}) , have been obtained from density and speed of sound. The critical micelle concentration (CMC) of cetyltrimethylammonium bromide (CTAB) is found to decrease with an increase in [antibiotic drug] and increase with an increase in temperature, accounting for the fact that hydrophilic dehydration plays a decisive role for micellization to take place. The various thermodynamic parameters indicate the spontaneity of micellization in the presence of drug moiety. The CMC values have been calculated using pyrene as a fluorescent probe at room temperature, and a good qualitative correlation is found to exist well with the CMC values determined using speed of sound and conductivity measurements.     

λ-PHASE TRANSITIONS IN ICE IH NEAR THE MELTING POINT

This study gives our predictions for the thermal expansivity α _p , isothermal compressibility κ _T , and specific heat Cp near the melting point for ice Ih. We calculate those thermodynamic quantities as functions of temperature and pressure near the melting point using the experimental data for the thermal expansivity as a function of pressure from the literature. The Pippard relations are validated by plotting C_p against α _p and also α _p against κ _T linearly close to the melting point in ice Ih. We deduce the values of the slope ?P _m /?T from those linear plots, which are very close to the experimental value obtained from the P-T phase diagram of ice Ih along the melting curve.     

Effect of Schiff Bases Containing Pyridyl Group as Corrosion Inhibitors for Low Carbon Steel in 0.1 M HCl

The inhibiting effect of four newly synthesised Schiff bases containing pyridyl group was investigated on the corrosion of low carbon steel in 0.1 M hydrochloric acid solution under various conditions by potentiodynamic polarisation method and impedance measurements. The Schiff bases used were 2-((1Z)-1-aza-2-(2-pyridyl)vinyl)benzene-1-thiol, (1Z)-1-aza-1,2- di(2-pyridyl)ethene, [((1Z)-1-aza-2-(2-pyridyl)vinyl)amino]benzene-1-thione and 2-((1Z)-1-aza-2-(2-pyridyl)vinyl)benzothiazole. All the Schiff bases inhibit corrosion of low carbon steel and their inhibition efficiencies increase with decrease in temperature and increase in concentration. The difference in protection actions of the inhibitors can be attributed to the presence of substituents in the structures that increase or decrease the electron density on the azomethine (–C=N–) group. Polarisation curves indicate that the Schiff bases act as anodic inhibitors. AC impedance and potentiodynamic polarisation measurements reveal that the compounds are adsorbed on the steel surface and the adsorption obeys the Temkin isotherm. Activation parameters (E_a, ΔH*, ΔS*) for the corrosion of low carbon steel in 0.1 M HCl were calculated and showed that corrosion was much reduced in the presence of inhibitors.     

Thermal and mechanical properties of semi‐interpenetrating polymer networks composed of diisocyanate‐bridged,four‐armed,star‐shaped ε‐caprolactone oligomers and poly(ε‐caprolactone)

Semi‐interpenetrating polymer networks (S‐IPNs) were prepared by the reactions of hydroxyl‐terminated four‐armed, star‐shaped ε‐caprolactone oligomers with degrees of polymerization per one oligocaprolactone chain (ns) of 3, 5, and 10 and 2,4‐tolylene diisocyanate (TDI) in the presence of poly(ε‐caprolactone) (PCL). In the dynamic mechanical analysis of the S‐IPN [2,4‐tolylene diisocyanate bridged hydroxyl‐terminated four‐armed, star‐shaped ε‐caprolactone oligomer (TH4CLO)/PCL], only one tan δ peak was observed; its temperature increased with increasing TH4CLO content and with decreasing n value. Differential scanning calorimetric analyses of the TH4CLOs and TH4CLO/PCLs revealed that the TH4CLOs with ns of 3 and 5 were amorphous, whereas TH4CLO with an n of 10 was semicrystalline and that the crystallization of the PCL chain for TH4CLO/PCLs was more strongly disturbed with increasing TH4CLO content and decreasing n value. Although the tensile strength, modulus, and elongation at break of TH4CLO were much lower than those of PCL, those values increased with the n value. Although the tensile strength and modulus of the TH4CLO/PCLs decreased with increasing TH4CLO content, TH4CLO (n = 3)/PCL 50/50 showed the highest elongation at break (314%) among the S‐IPNs because of the suppression of crystallization of the polycaprolactone chain. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4229–4236, 2013     

Why would apparent κ linearly change with O/C? Assessing the role of volatility,solubility, and surface activity of organic aerosols

Correlations between O/C and cloud condensation nucleus activity, represented by κ, are a computationally efficient approach to estimate the impact of aerosol aging on cloud formation and climate; however, previously reported correlations between these two variables are empirical and vary widely in their slopes and extrapolations to high O/C values. This study proposes a theoretical framework that bridges elemental ratios, volatility, solubility, and κ. The framework estimates intrinsic κ based on molecular formulas of organics composed of carbon, oxygen, and hydrogen that partition to condensed phase, and then it estimates apparent κ considering solubility distribution parameterized by O/C. This article applied the new framework to the two-dimensional volatility basis set (2D-VBS) and found that distribution of O/C and molecular size play key roles in determining apparent κ. For highly soluble organics, κ is dictated by gas-particle partitioning and it is unlikely for κ of organics to go beyond 0.3 in typical ambient organic material loadings. Sensitivity analysis showed that surface-active compounds are not likely to profoundly alter the overall trend within a reasonable range of surface activity. This framework provides a simple yet plausible explanation of why κ would and would not correlate with O/C; distributions of OA in the 2D-VBS as well as the presence of inorganic salts determine the trend. The framework opens up new opportunities to evaluate two-dimensional representations of organic aerosol aging using κ, a significant advancement from the current empirical linear fits to κ and O/C.

Copyright © 2017 American Association for Aerosol Research     

Kinetics of layer formation and corrosion processes of passive iron in acid solutions

The kinetics of the layer formation process and the corrosion process have been determined from the relation between the stationary (i_c,0) and non-stationary (i_c) corrosion rates and the rate of layer formation (i_ι) at passive iron in acid solutions. The rates of both processes depend on the potential difference ε_2,3 at the passive-oxide/electrolyte-solution interface. The fact that i_c and i_c,0 are independent of the electrode potential is explained by a nearly constant composition of the passive oxide in contact with the solution (Fermi level within the band gap).Linear relations, such as log i_ι⁺ = a + (α_ι⁺/α_c⁺)·log i_c, are obtained, which are explained by charge-transfer hindrance. The apparent charge-transfer coefficients are α_ι⁺ = 1·43 and α_ι^? = 0·57 for the layer formation and removal reaction, and α_c⁺ = 0·84 for the corrosion reaction. From the pH dependence (pH = 0.35–2·90) of i_ι and i_c,0 the reaction orders of the hydrogen ions are found to be approximately μn_ι⁺ = ?1 and ν_c = 0. The corrosion cd depends on the sulphate concentration, with a reaction order ν_s = ß = 0·16. From this, the kinetics of the oxide formation H₂O·aq ? OH^? · ox + H⁺·aq (preceding equilibrium), OH^?·ox?O^2?·ox + H⁺·aq (rate-determining) and the kinetics of the corrosion process Fe³⁺·ox + SO₄^2?·aq ? FeSO₄⁺·ad (adsorption equilibrium, Temkin conditions), FeSO₄⁺·ad → FeSO₄⁺·aq (rate-determining), with following dissociation of the complex can be deduced. The apparent charge-transfer coefficients are interpreted by α_ι⁺ = 1 + α_ι, α_ι^? = 1 ? α_ι and α_c⁺ = α + 2ßγ_s (ga_ι, α, true charge-transfer coefficients).     

Mixed Micellization Behavior of (Chlorpromazine Hydrochloride + Cetyltrimethylammonium Bromide) System in Aqueous Solutions of Glycine

We have examined the mixed micellar behavior of {amphiphilic drug; chlorpromazine hydrochloride (CPZ) + cationic surfactant; cetyltrimethylammonium bromide (CTAB)} at varying mole fractions of CPZ (α_CPZ = 0.2, 0.4, 0.6, and 0.8) in (0.1, 0.3, and 0.5) mol kg⁻¹ glycine_(aq) solutions at 298.15, 308.15, and 318.15 K, by using conductometric, volumetric, isentropic compressibility, UV–visible absorbance, fluorescence, and dynamic light scattering (DLS) techniques. The critical micelle concentration (CMC) values obtained from above measurements have been utilized to calculate the thermodynamic parameters (ΔG^°_m, ΔH^°_m, and ΔS^°_m) and degree of ionization (α) at studied temperatures and concentrations. The partial specific volume (φ_v), partial specific isentropic compression (φ_κ), and isentropic compressibility (κ_s) have been calculated from the experimental density and speed of sound measurements and the results have been used to elucidate different interactions occurring in these systems. These results are further supported by UV–visible absorbance and fluorescence spectroscopic studies. The hydrodynamic diameters (D_h) of the mixed micellar system have been measured from the DLS studies. Thermodynamic and spectroscopic studies depict the dominance of hydrophobic/hydrophilic-hydrophobic interactions between the alkyl (R = C₁₆H₃₃) chain of CTAB or hydrophobic tricyclic scaffolding of CPZ/Br⁻/N⁺-CH₃ group of CTAB or hydrophilic group i.e., tertiary amine portion of CPZ with hydrophobic group of glycine.     

Thermal stability improvement of hopcalite catalyst

The properties of hopcalite in alumina matrix formed by rehydration of transition aluminas have been investigated in comparison with conventional hopcalite catalyst. By using X-ray diffraction, thermal analysis and activity measurements in combustion ofn-butane and air mixture it was found that the presence of alumina matrix leads to improvement of thermal stability at elevated temperatures and to limitation of spinel phase recrystallization. The modified catalyst was found to show much higher activity after thermal treatment at temperatures above 773 K than pure hopcalite at the same conditions.     

Crystallization kinetics and melting behavior of poly[(trimethylene terephthalate)‐co‐(29 mol % ethylene terephthalate)] copolyester

The copolyester was characterized as having 71 mol % trimethylene terephthalate units and 29 mol % ethylene terephthalate units in a random sequence according to the NMR spectra. Differential scanning calorimeter (DSC) was used to investigate the isothermal crystallization kinetics in the temperature range (T_c) from 130 to 170°C. The melting behavior after isothermal crystallization was studied using DSC and temperature‐modulated DSC by varying the T_c, the crystallization time, and the heating rate. The DSC thermograms and wide‐angle X‐ray diffraction patterns reveal that the complex melting behavior involves melting‐recrystallization‐remelting and different lamellar crystals. As the T_c increases, the contribution of recrystallization gradually falls and finally disappears. A Hoffman‐Weeks linear plot yields an equilibrium melting temperature of 198.7°C. The kinetic analysis of the growth rates of spherulites and the change in the morphology from regular to banded spherulites indicate that a regime II→III transition occurs at 148°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Prevention of Ice Accretion on Aluminum Surfaces by Enhancing Their Hydrophobic Properties

The accretion of ice on the surfaces of power network systems, aircraft, communication networks, etc., is known to cause serious problems that often lead to costly safety issues. An ideal solution would be to prevent ice from accumulating in the first place, rather than waiting for ice to accrete and then to de-ice which is both time-consuming and expensive. This may be accomplished by depositing coating materials that are icephobic. A low dielectric constant surface is expected to reduce the adhesion of ice due to the screening of mirror charges, thereby eliminating one of the strongest interaction forces — the electrostatic force of attraction — at the ice–surface interface. Superhydrophobic surfaces, which demonstrate high water-repellency due to the negligible contact area of water with these surfaces, are also expected to minimize the contact area of ice. In the present research work, both concepts were studied by producing superhydrophobic nanorough low-ε (dielectric) surfaces on aluminum. Superhydrophobic properties were achieved on surfaces of aluminum by creating a certain nanoroughness using a chemical etch followed by 'passivation' of the surface by a low surface energy coating of rf-sputtered Teflon, providing a water contact angle greater than 160°. The same behavior is reported even when the nanorough substrates were coated with dielectric thin films of ZnO (lower ε) or TiO 2 (higher ε) prior to passivation. It is found that the superhydrophobic nanorough low energy surfaces are also icephobic and the presence of a low dielectric constant surface coating of Teflon (ε = 2) allows a considerable reduction of the ice adhesion strength. Ice adhesion strengths were determined using a centrifugal ice adhesion test apparatus.     

Structure-activity relationships between stimulus molecule and response of a pheromone receptor cell in turnip moth,Agrotis segetum

The response of an antennal receptor cell of the turnip moth,Agrotis segetum, was recorded during stimulation with a series of (Z)-7-dodecenyl acetate analogs with structural variations of the acetate group. The investigated receptor cell is known to be highly selective to (Z)-7-dodecenyl acetate. All parts of the acetate group were found to be of great importance for full biological activity. The results indicate very strict requirements on the shape of the polar functional group, as well as on its electron distribution for a successful interaction with the antennal receptor cell.     

Preparation and thermal characterization of graft copolymer obtained by radiation grafting of individual and binary monomer systems

Graft copolymers were obtained by radiation-induced grafting of vinyl acetate (VAc) and N-vinylpyrrolidone (NVP) individually and in binary mixture on to polypropylene (PP) films. The effect of some grafting conditions on the grafting yield was determined. The addition of Cu₂Cl₂ as inhibitor to the reaction medium inhibited the homopolymerization of the comonomer. The grafting process was remarkably enhanced by using dioxan as a diluent compared with other solvents used. The addition of some inorganic salts has a great influence on the individual grafting of both monomers. The gel percent in the graft copolymer was determined; it increased as the grafting yield increased. The swelling behaviour and electrical conductivity for the grafted films slightly increased by grafting. The changes in thermal parameters such as glass transition (T_g), melting (T_m) and recrystallization (T_rc) temperatures and heats of melting (ΔH_m) and recrystallization (ΔH_rc) of the graft copolymers were also followed by differential scanning calorimetry (DSC). These thermal parameters of PP were varied by grafting with VAc and NVP and depend on the graft yield, which reflects the change in its crystalline domains and formation of crosslinks in the graft chains. The heat of recrystallization of the graft copolymer by cooling from the molten state decreases by grafting which is a good indication of crosslink formation, since crosslinking decreases the crystallizability of the polymer matrix.     

Organic–inorganic collagen/iota-carrageenan/hydroxyapatite hybrid membranes are bioactive materials for bone regeneration

This study aimed to produce biomembranes with controlled degradability for application in bone regeneration in order to stimulate biological reactions necessary to improve bone formation. Hydrogels were prepared by dissolving hydrolyzed collagen (HC) and iota-carrageenan (ι-Carr) in aqueous mixtures containing CaCl₂ and H₃PO₄. A rise in pH by exposure to NH_3(g) caused mineral precipitation into the hydrogel. Subsequently, the membranes were fabricated by solvent casting. Infrared spectroscopy and X-ray diffraction attested hydroxyapatite formation. The crystallite size was close to 12 nm, which was smaller than the size reported for human bone apatite. The membranes induced bone-like apatite precipitation in simulated body fluid. The carrageenan content modulated the membrane mechanical behavior. Membranes with controlled degradability were obtained by using higher amount of this polysaccharide. These membranes were able to release HC in physiological conditions. The surface properties were evaluated in terms of wettability and surface energy (γ_S) by means of contact angle (θ_c) measurements. Low θ_c (8.5–16.8) indicated that the hybrid membranes were hydrophilic, while higher γ_S values, around 70.6 mJ.m⁻², could favor biomolecule incorporation into the surface. Our data set evidenced that these materials could potentially be used as a temporary guided tissue regeneration membrane with the possibility of inducing bone regeneration. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48004.     

Thermal properties and transition studies of multi-wall carbon nanotube/nylon-6 composites

Transition behavior and thermal properties of a multi-wall carbon nanotube (MWCNT)/nylon-6 composite (P-composite) made by in situ polymerization and subsequently structurally modified by high-pressure–high-temperature treatment have been established. The thermal conductivity (κ) of nylon-6 improved ∼27% by the addition of 2.1 wt.% MWCNT filler simultaneously as the heat capacity per unit volume decreased ∼22% compared with that of nylon-6 at 1 atm and 298 K. Moreover, the MWCNT filler raises the glass transition temperature (T_g) of nylon-6, but the pressure dependence of T_g remains unchanged. A model for κ indicates that the interfacial thermal resistance between the MWCNT filler and the nylon-6 matrix decreases 20% up to 1 GPa and most significantly above 0.8 GPa. P-composite was structurally modified by a sluggish cold-crystallization transition at 1.0 GPa, 530 K, which further increased κ by as much as ∼37% as the crystallinity of nylon-6 improved from 31% to 58% with a preferred crystal orientation and increased crystal size.     

Low thermal conductivity of SrTiO3−LaTiO3 and SrTiO3−SrNbO3 thermoelectric oxide solid solutions

Electron-doped SrTiO₃ has been attracting attention as oxide thermoelectric materials, which can convert wasted heat into electricity. The power factor of the electron-doped SrTiO₃, including SrTiO₃-LaTiO₃ and SrTiO₃-SrNbO₃ solid solutions, has been clarified. However, their thermal conductivity (κ) has not been clearly identified thus far. Only a high κ (>12 W m⁻¹ K⁻¹) has been assumed from the electron contribution based on Wiedemann–Franz law. Here, we show that the κ of the electron-doped SrTiO₃ is lower than the assumed κ, and its highest ZT exceeded 0.1 at room temperature. The κ slightly decreased with the carrier concentration (n) when n is below 4 × 10²¹ cm⁻³. In the case of SrTiO₃-SrNbO₃ solid solutions, an upturn in κ was observed when n exceeds 4 × 10²¹ cm⁻³ due to the contribution of conduction electron to the κ. On the other hand, κ decreased in the case of SrTiO₃-LaTiO₃ solid solutions probably due to the lattice distortion, which scatters both electrons and phonons. The highest ZT was 0.11 around n = 1 × 10²¹ cm⁻³. These findings would be useful for the future design of electron-doped SrTiO₃-based thermoelectric materials.     

Investigation of the properties of decaoxyethylene <Emphasis Type="Italic">n</Emphasis>-dodecyl ether,C<Subscript>12</Subscript>E<Subscript>10</Subscript>, in the aqueous sugar-rich region

Interfacial, thermodynamic, and morphological properties of decaoxyethylene n-dodecylether [CH₃ (CH₂)₁₁(OCH₂CH₂)₁₀OH](C₁₂E₁₀) in aqueous solution were analyzed by tensiometric, viscometric, proton nuclear magnetic resonance (NMR), and small-angle neutron scattering (SANS) techniques. Dynamic and structural aspects at different temperatures in the absence and presence of sugars at different concentrations were measured. Critical micelle concentrations (CMC) were determined by surface tension measurements in the presence of ribose, glucose, and sucrose. The heat capacity (ΔC _p.m.), transfer enthalpy (ΔH _m.tr.), transfer heat capacities (ΔC _p.m.tr.), micellization constant (K _m ), Setchenow constant (K _S ^N ), and partition coefficient (q) were determined and discussed as an extension of the usual thermodynamic quantities of micellization and adsorption at the air-water interface. An enthalpy-entropy compensation effect was observed with an isostructural temperature (T _c ) of about 310 K for both micellization and interfacial adsorption. SANS measurements were taken to elucidate structural information, viz., aggregation number (N _agg), shape, size, and number density (N _m ) on C₁₂E₁₀ micelles in D₂O at different concentrations of sugars (0.05, 0.02, 0.3, and 0.5 M) and temperatures (30, 45, and 60°C). Intrinsic viscosity gave the hydrated micellar volume (V _h ), volume of the hydrocarbon core (V _c ), and volume of the palisade layer of the oxyethylene (OE) unit (V _OE). SANS, as well as rheological data, supported the formation of nonspherical micelles with or without sugars. By SANS, we also observed that at the studied temperature intervals, oblate ellipsoid micelles changed into prolate ellipsoids and the number density of micelles decreased with an increase in temperature both in the presence and in the absence of sugars and also on increasing the concentration of sugars. Proton NMR showed a change in chemical shift of the OE group of micelles above the CMC. We also studied the phase separation of C₁₂E₁₀ by sugars in cloud point measurements.     

Radiolabeled 6-(2, 3-Dichlorophenyl)-N4-methylpyrimidine-2, 4-diamine (TH287): A Potential Radiotracer for Measuring and Imaging MTH1

MTH1 (MutT homolog 1) or NUDT1 (Nudix Hydrolase 1), also known as oxidized purine nucleoside triphosphatase, has potential as a biomarker for monitoring cancer progression and quantifying target engagement for relevant therapies. In this study, we validate one MTH1 inhibitor TH287 as a PET MTH1 radiotracer. TH287 was radiolabeled with tritium and the binding of [³H]TH287 to MTH1 was evaluated in live glioblastoma cells (U251MG) through saturation and competitive binding assays, together with in vitro enzymatic assays. Furthermore, TH287 was radiolabeled with carbon-11 for in vivo microPET studies. Saturation binding assays show that [³H]TH287 has a dissociation constant (K_d) of 1.97 ± 0.18 nM, B_max of 2676 ± 122 fmol/mg protein for U251MG cells, and n_H of 0.98 ± 0.02. Competitive binding assays show that TH287 (K_i: 3.04 ± 0.14 nM) has a higher affinity for MTH1 in U251MG cells compared to another well studied MTH1 inhibitor: (S)-crizotinib (K_i: 153.90 ± 20.48 nM). In vitro enzymatic assays show that TH287 has an IC₅₀ of 2.2 nM in inhibiting MTH1 hydrolase activity and a K_i of 1.3 nM from kinetics assays, these results are consistent with our radioligand binding assays. Furthermore, MicroPET imaging shows that [¹¹C]TH287 gets into the brain with rapid clearance from the brain, kidney, and heart. The results presented here indicate that radiolabeled TH287 has favorable properties to be a useful tool for measuring MTH1 in vitro and for further evaluation for in vivo PET imaging MTH1 of brain tumors and other central nervous system disorders.     

Discovery of the Griffiths phase in the quaternary nitrides Ge1−xSnxNFe3

We report the Griffiths phase (GP) and transport behavior in the quaternary antiperovskite nitrides Ge_1−xSn_xNFe₃ by a series of systematical magnetic susceptibility and thermoelectric behavior measurements. All the corresponding fitting exponent parameters λ_GP = 0.852 and 0.854 completely satisfy 0 ≤ λ ≤ 1 in GP regions for Ge_0.7Sn_0.3NFe₃ and Ge_0.8Sn_0.2NFe₃, respectively, indicating the different ferromagnetic concentrations in the system. An observed structural transition from distorted tetragonal structure (I4/mcm) to cubic antiperovskite (Pm3m) with increasing dopants should be responsible for the GP in Ge_1−xSn_xNFe₃, which results in a magnetic phase transition from ferromagnetism (FM) to antiferromagnetism (AFM). Furthermore, the studies of electrical transport properties indicate that the Ge_1−xSn_xNFe₃ series of compounds perform a Fermi liquid behavior at low temperature while the stronger electron-phonon scatterings are found in the high-temperature region. In addition, the intensive electron–electron correlation is also determined since much higher value of lattice thermal conductivity κ_l than the one of electronic thermal conductivity κ_e.