Liquid phase contained in porous rock as observed by proton magnetic relaxation

High power proton relaxometry was applied to investigate the liquid phase contained in porous rock. Proton free induction decays and spin-lattice relaxation times allowed us to investigate the pore distribution and the contribution of mobile and of immobilized liquid. The differences in pore distributions in oil-containing limestone and in Węglowicki sandstone were found. The fractal exponent for pore distribution in Węglowicki sandstone was fitted using both stretched exponential and modified stretched exponential models. The results of both approaches are compared

The effect of water accessible paramagnetic ions on subcellular structures formed in developing wheat photosynthetic membranes as observed by NMR and by sorption isotherm

The rehydration from the gaseous phase of the developing native or EDTA-washed from unbound and loosely bound paramagnetic ions wheat thylakoid membrane lyophilizate was investigated using hydration kinetics, sorption isotherm, and high power proton relaxometry. Hydration time courses are single exponential for all target humidities. The sorption isotherm is well fitted by the Dent model, with the mass of water saturating primary binding sites equal toΔ M/m$\text{}_{ }$0=0.024 and 0.017 for native and EDTA-washed membranes, respectively. Proton free induction decays distinguish: (i) a Gaussian component, S$\text{}_{0}$, coming from protons of solid matrix of lyophilizate; (ii) a Gaussian component, S$\text{}_{1}$, from water bound to the primary water binding sites in proximity of water accessible paramagnetic ions; (iii) an exponentially decaying contribution, $L$\text{}_{1}$$, from water tightly bound to lyophilizate surface; and (iv) exponentially decaying loosely bound water pool, L$\text{}_{2}$. Sorption isotherm fitted to NMR data shows a significant contribution of water "sealed" in membrane structures (Δ M$\text{}_{s}$/m$\text{}_{0}$=0.052 for native and 0.061 for EDTA-washed developing membranes, respectively)

Bound water structure on the surfaces of Usnea antarctica as observed by NMR and sorption isotherm

Hydration courses and proton free induction decays are recorded at 30 MHz for Usnea antarctica thalli hydrated from gaseous phase. NMR data combined with gravimetry allow one to distinguish two fractions of tightly bound water, and loosely bound/free water pool. No water fraction "sealed" in thallus structures is present in U. antarctica

Water bound in elytra of the Weevil Liparus glabrirostris (Küster, 1849) by NMR and sorption isotherm (Coleoptera: Curculionidae)

Scanning electron microscopy micrograms of the elytra of Liparus glabrirostris showed a different dorsal and ventral surface and a multilayered inner structure. Hydration kinetics, sorption isotherm, and proton free induction decays are measured for hydrated elytra of the weevil species Liparus glabrirostris (Coleoptera: Curculionidae) in the atmosphere with controlled humidity. Very tightly bound water fraction with the mass Δ m/$m_0$ = 0.037 ± 0.004, and very short hydration time, tightly bound water Δ m/$m_0$ = 0.034 ± 0.009, and hydration time $t_1^{h}$ = (3.31 ± 0.93) h, and finally loosely bound water fraction with $t_2^{h}$ = (25.5 ± 7.8) h were distinguished. The sorption isotherm is sigmoidal in form, with the mass of water saturating primary water binding sites equal of Δ M/$m_0$ = 0.036. The proton free induction decays show the presence of solid signal (well fitted by a Gaussian function) from elytra ($T_{2G}$* ≈ 18 μs), the immobilized water fraction ($T_{2L_1}$* ≈ 120 μs) and mobile water pool ($T_{2 L_2}$* ≈ 300 μs). The hydration dependence of the water bound in elytra of L. glabrirostris, L/S is linear showing the absence of water-soluble solid fraction and negligible content of water pool "sealed" in pores of the structure

Initial phases of antarctic Ramalina terebrata Hook f. & Taylor thalli rehydration observed by proton relaxometry

Hydration kinetics, sorption isotherm, and proton free induction decays are measured for Ramalina terebrata thalli rehydrated from gaseous phase. Very tightly, tightly, and loosely bound water fractions are distinguished. Sorption isotherm is sigmoidal in form with the mass of water saturating primary water binding sites equal to Δ m/$m_0$ = 0.046. Proton free induction decays show the presence of immobilized water fraction ($T_{2 L_1}$* ≈ 100 μs) and mobile water pool ($T_{2 L_2}$* ≈ 330 μs). Sorption isotherm fitted to the NMR data shows the absence of water fraction "sealed" in pores of dry thallus

The effect of mild rehydration on freeze-dried dipalmitoylphosphatidylcholine (DPPC) multilamellar membranes as observed by proton NMR and sorption isotherm

Between neighbouring bilayers of lyophilized dipalmitoylphosphatidylcholine (DPPC) multilamellar vesicles the total number of water molecules equals 9 H2O molecules/1 DPPC molecule. One of these molecules is very tightly bound to the lipid molecule, seven are in immobilized (tightly bound) water fraction whereas the last one belongs to mobile water fraction. The rehydration from the gaseous phase of the DPPC model membranes was investigated using hydration kinetics, sorption isotherm, and high power proton relaxometry. The obtained data for DPPC were compared with these obtained for wheat photosynthetic membranes. Rehydrated photosynthetic membranes differ from DPPC model membranes in hydration kinetics. The average hydration time has a similar value: (22.0 ± 2.8) h (photosynthetic membrane) and (19.8 ± 1.6) h (DPPC), however hydration kinetics was described by one-exponential function for photosynthetic membrane, while for model membrane it shows fine double exponential form. The sigmoidal form: of sorption isotherm is better fitted using Dent model than by the Brunauer-Emmett-Teller formula. The Brunauer-Emmett-Teller/Dent deviation parameter b =0.93 either for photosynthetic or for model membranes. The mass of water saturating primary water binding sites equals ΔM/m0= 0.017 (wheat photosynthetic membranes) and 0.027 (DPPC). The detected by NMR-isotherm study mass of water "sealed" in model membrane structures was about ΔMs/m0=0.182 (about 7-8 H2O molecules /1 DPPC molecule), and ΔMs/m0= 0.066 for photosynthetic membrane

Data regarding particle size distribution, thermal properties and gaseous phase hydration of co-milled solid dispersions composed of tadalafil and Soluplus

A mechanical activation of the solid particles upon high-energy ball milling may considerably change the physicochemical properties of pharmaceutical compounds, including the morphology, particle size distribution, thermal properties, and surface interactions with water vapour upon gaseous phase hydration. Assessment of these changes is crucial for optimizing the manufacturing process of enabling drug products. In this article, we provide a detailed characterization of binary co-milled solid dispersions composed of tadalafil and Soluplus using a laser diffraction method, differential scanning calorimetry (DSC), gravimetric measurements and solid state (1)H- NMR spectroscopy. The data presented in this article is directly related to our previously published research article. They complement information on the impact that both formulation and process variables may have on the properties of these binary powder formulations

Rehydration of CTMA modified DNA powders observed by NMR

The rehydration of salmon sperm deoxyribonucleic acid (DNA) and cetyltrimethylammonium chloride $(C_{19}H_{42}ClN)$ complexes was observed using hydration kinetics, sorption isotherm, and high power proton relaxometry (at 30 MHz). The hydration kinetics shows (i) a very tightly bound water not removed by incubation over silica gel ($A_0^{h}$ = 0.061 ± 0.004), (ii) a tightly bound water saturating at $A_1^{h}$ = 0.039 ± 0.011, with the hydration time $t_1^{h}$ = (1.04 ± 0.21) h, a loosely bound water fraction (iii) with the hydration time $t_2^{h}$ = (19.1 ± 3.2) h and the contribution progressively increasing with the air humidity. For the hydration at $p//p_0$ = 100%, after $t_0$ = (152.6 ± 2.5) h of incubation the swelling process begins. The swelling time was $t_3^{h}$ = (12.5 ± 5.4) h, and the swelling amplitude $A_3^{h}$ = 0.140 ± 0.016. The sorption isotherm is sigmoidal in form and is fitted by the Dent model with the mass of water saturating primary binding sites Δ M/$m_0$ = 0.102 ± 0.021. Proton free induction decay is a superposition of the immobilized proton signal (Gaussian, with $T_{2S}$* ≈ 30 μs) and two liquid signal components coming from tightly bound ($T_{2 L_1}$* ≈ 100 μs) and loosely bound water fraction with the amplitude proportional to the mass of water added ($T_{2 L_2}$* ≈ 1000 μs)

Hydration properties of selected DNA-lipid complexes

Zbadano dwa modelowe kompleksy lipidowe DNA z surfaktantami zawierającymi jeden (CTMA) lub dwa (DDCA) łańcuchy alifatyczne. Wyznaczono kinetykę ich hydratacji oraz izotermę sorpcyjną. Wykazano, że zastosowanie lipidowego surfaktantu z udziałem dwóch łańcuchów alifatycznych ogranicza liczbę cząsteczek wody trwale związanej z helisą DNA.Two model DNA-lipid complexes with the surfactants containing single (CTMA) or double (DDCA) aliphatic chains were investigated. Hydration kinetics and sorption isotherms were determined. The data were interpreted using BET and Dent sorption isotherm models. It was found that the use of lipid surfactant with double aliphatic chain reduce the number of water molecules tightly and permanently bound to DNA helix