1
|
Effects of viscoelasticity on moisture sorption of maltodextrins. Food Hydrocoll 2023. [DOI: 10.1016/j.foodhyd.2023.108481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
2
|
Zhu Y, Li X, Wu P, Gan L, Hao H, Ma X, Cai Z. Numerical simulation and modeling of viscous fluid residence time distribution in the melt spinning pack. ASIA-PAC J CHEM ENG 2022. [DOI: 10.1002/apj.2855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Yiwei Zhu
- College of Chemical Engineering Beijing University of Chemical Technology Beijing China
| | - Xin Li
- State Key Laboratory of biogenic fiber manufacturing technology Chinese Academy of Textile Beijing China
| | - Pengfei Wu
- State Key Laboratory of biogenic fiber manufacturing technology Chinese Academy of Textile Beijing China
| | - Lihua Gan
- State Key Laboratory of biogenic fiber manufacturing technology Chinese Academy of Textile Beijing China
| | - Haoran Hao
- College of Chemical Engineering Beijing University of Chemical Technology Beijing China
| | - Xin Ma
- College of Chemical Engineering Beijing University of Chemical Technology Beijing China
| | - Ziqi Cai
- College of Chemical Engineering Beijing University of Chemical Technology Beijing China
| |
Collapse
|
3
|
Bama JA, Dudognon E, Affouard F. Impact of Low Concentration of Strongly Hydrogen-Bonded Water Molecules on the Dynamics of Amorphous Terfenadine: Insights from Molecular Dynamics Simulations and Dielectric Relaxation Spectroscopy. J Phys Chem B 2021; 125:11292-11307. [PMID: 34590855 DOI: 10.1021/acs.jpcb.1c06087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The impact of low water concentration of strongly hydrogen-bonded water molecules on the dynamical properties of amorphous terfenadine (TFD) is investigated through complementary molecular dynamics (MD) simulations and dielectric relaxation spectroscopy (DRS) experiments. In this article, we especially highlight the important role played by some residual water molecules in the concentration of 1-2% (w/w) trapped in the TFD glassy matrix, which are particularly difficult to remove experimentally without a specific heating/drying process. From MD computations and analyses of the hydrogen bonding (HB) interactions, different categories of water molecules are revealed and particularly the presence of strongly HB water molecules. These latter localize themselves in small pockets in empty spaces existing in between the TFD molecules due to the poor packing of the glassy state and preferentially interact with the polar groups close to the flexible central part of the TFD molecules. We present a simple model which rationalizes at the molecular scale the effect of these strongly HB water molecules on dynamics and how they give rise to a supplementary relaxation process (namely process S) which is detected for the first time in the glassy state of TFD annealed at room temperature while this process is completely absent in a non-annealed glass. It also explains how this supplementary relaxation is coupled with the intramolecular motion (namely process γ) of the very flexible central part of the TFD molecule. The present findings help to understand more generally the microscopic origin of the secondary relaxations often detected by DRS in the glassy states of molecular compounds for which the exact nature is still debated.
Collapse
Affiliation(s)
- Jeanne-Annick Bama
- University Lille, CNRS, INRAE, Centrale Lille, UMR 8207-UMET-Unité Matériaux et Transformations, Lille F-59000, France
| | - Emeline Dudognon
- University Lille, CNRS, INRAE, Centrale Lille, UMR 8207-UMET-Unité Matériaux et Transformations, Lille F-59000, France
| | - Frédéric Affouard
- University Lille, CNRS, INRAE, Centrale Lille, UMR 8207-UMET-Unité Matériaux et Transformations, Lille F-59000, France
| |
Collapse
|
4
|
Huang F, Chen P, Wang J, Li Z, Gao Z, Derksen JJ. Refractive Index-Matched PIV Experiments and CFD Simulations of Mixing in a Complex Dynamic Geometry. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c00169] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fenglei Huang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Peng Chen
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Junhao Wang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Zhipeng Li
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Zhengming Gao
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- State Key Laboratory of Chemical Resource Engineering, School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jos J. Derksen
- School of Engineering, University of Aberdeen, Aberdeen AB24 3UE, U.K
| |
Collapse
|
5
|
Liu Q, Liggio J, Li K, Lee P, Li SM. Understanding the Impact of Relative Humidity and Coexisting Soluble Iron on the OH-Initiated Heterogeneous Oxidation of Organophosphate Flame Retardants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:6794-6803. [PMID: 31117542 DOI: 10.1021/acs.est.9b01758] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The current uncertainties in the reactivity and atmospheric persistence of particle-associated chemicals present a challenge for the prediction of long-range transport and deposition of emerging chemicals such as organophosphate flame retardants, which are ubiquitous in the global environment. Here, the OH-initiated heterogeneous oxidation kinetics of organophosphate flame retardants (OPFRs) coated on inert (NH4)2SO4 and redox-active FeSO4 particles were systematically determined as a function of relative humidity (RH). The derived reaction rate constants for the heterogeneous loss of tricresyl phosphate (TCP; kTCP) and tris(2-butoxyethyl) phosphate (TBEP; kTBEP) were in the range of (2.69-3.57) × 10-12 and (3.06-5.55) × 10-12 cm3 molecules-1 s-1, respectively, depending on the RH and coexisting Fe(II) content. The kTCP (coated on (NH4)2SO4) was relatively constant over the investigated RH range while kTBEP was enhanced by up to 19% with increasing RH. For both OPFRs, the presence of Fe(II) enhanced their k by up to 53% over inert (NH4)2SO4. These enhancement effects (RH and Fe(II)) were attributed to fundamental changes in the organic phase state (higher RH lowered particle viscosity) and Fenton-type chemistry which resulted in the formation of reactive oxygen species, respectively. Such findings serve to emphasize the importance of ambient RH, the phase state of particle-bound organics in general, and the presence of coexisting metallic species for an accurate description of the degradation kinetics and aging of particulate OPFRs in models used to evaluate their atmospheric persistence.
Collapse
Affiliation(s)
- Qifan Liu
- Atmospheric Science and Technology Directorate, Science and Technology Branch , Environment Canada , 4905 Dufferin Street , Toronto , Ontario M3H 5T4 , Canada
| | - John Liggio
- Atmospheric Science and Technology Directorate, Science and Technology Branch , Environment Canada , 4905 Dufferin Street , Toronto , Ontario M3H 5T4 , Canada
| | - Kun Li
- Atmospheric Science and Technology Directorate, Science and Technology Branch , Environment Canada , 4905 Dufferin Street , Toronto , Ontario M3H 5T4 , Canada
| | - Patrick Lee
- Atmospheric Science and Technology Directorate, Science and Technology Branch , Environment Canada , 4905 Dufferin Street , Toronto , Ontario M3H 5T4 , Canada
| | - Shao-Meng Li
- Atmospheric Science and Technology Directorate, Science and Technology Branch , Environment Canada , 4905 Dufferin Street , Toronto , Ontario M3H 5T4 , Canada
| |
Collapse
|
6
|
Björklund S, Kocherbitov V. Water vapor sorption-desorption hysteresis in glassy surface films of mucins investigated by humidity scanning QCM-D. J Colloid Interface Sci 2019; 545:289-300. [DOI: 10.1016/j.jcis.2019.03.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/11/2019] [Accepted: 03/12/2019] [Indexed: 02/01/2023]
|
7
|
Nadler KA, Kim P, Huang DL, Xiong W, Continetti RE. Water diffusion measurements of single charged aerosols using H2O/D2O isotope exchange and Raman spectroscopy in an electrodynamic balance. Phys Chem Chem Phys 2019; 21:15062-15071. [DOI: 10.1039/c8cp07052k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report water diffusion measurements on single charged aerosols using isotope exchange in an electrodynamic balance.
Collapse
Affiliation(s)
- Katherine A. Nadler
- Department of Chemistry and Biochemistry
- University of California San Diego
- La Jolla
- USA
| | - Pyeongeun Kim
- Department of Chemistry and Biochemistry
- University of California San Diego
- La Jolla
- USA
| | - Dao-Ling Huang
- Department of Chemistry and Biochemistry
- University of California San Diego
- La Jolla
- USA
| | - Wei Xiong
- Department of Chemistry and Biochemistry
- University of California San Diego
- La Jolla
- USA
| | - Robert E. Continetti
- Department of Chemistry and Biochemistry
- University of California San Diego
- La Jolla
- USA
| |
Collapse
|
8
|
Shalaev E, Soper A, Zeitler JA, Ohtake S, Roberts CJ, Pikal MJ, Wu K, Boldyreva E. Freezing of Aqueous Solutions and Chemical Stability of Amorphous Pharmaceuticals: Water Clusters Hypothesis. J Pharm Sci 2018; 108:36-49. [PMID: 30055227 DOI: 10.1016/j.xphs.2018.07.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/13/2018] [Accepted: 07/17/2018] [Indexed: 11/24/2022]
Abstract
Molecular mobility has been traditionally invoked to explain physical and chemical stability of diverse pharmaceutical systems. Although the molecular mobility concept has been credited with creating a scientific basis for stabilization of amorphous pharmaceuticals and biopharmaceuticals, it has become increasingly clear that this approach represents only a partial description of the underlying fundamental principles. An additional mechanism is proposed herein to address 2 key questions: (1) the existence of unfrozen water (i.e., partial or complete freezing inhibition) in aqueous solutions at subzero temperatures and (2) the role of water in the chemical stability of amorphous pharmaceuticals. These apparently distant phenomena are linked via the concept of water clusters. In particular, freezing inhibition is associated with the confinement of water clusters in a solidified matrix of an amorphous solute, with nanoscaled water clusters being observed in aqueous glasses using wide-angle neutron scattering. The chemical instability is suggested to be directly related to the catalysis of proton transfer by water clusters, considering that proton transfer is the key elementary reaction in many chemical processes, including such common reactions as hydrolysis and deamidation.
Collapse
Affiliation(s)
- Evgenyi Shalaev
- Pharmaceutical Development, Allergan plc., Irvine, California 92612.
| | - Alan Soper
- ISIS Facility, UKRI-STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxon OX11 OQX, UK
| | - J Axel Zeitler
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
| | - Satoshi Ohtake
- Pfizer BioTherapeutics Pharmaceutical Sciences, Chesterfield, Missouri 63198
| | | | - Michael J Pikal
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, Storrs, Connecticut 06269
| | - Ke Wu
- Pharmaceutical Development, Allergan plc., Irvine, California 92612
| | - Elena Boldyreva
- Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russian Federation; Boreskov Institute of Catalysis SB RAS, Novosibirsk 630090, Russian Federation
| |
Collapse
|
9
|
Zhang Y, Cai C, Pang SF, Reid JP, Zhang YH. A rapid scan vacuum FTIR method for determining diffusion coefficients in viscous and glassy aerosol particles. Phys Chem Chem Phys 2017; 19:29177-29186. [DOI: 10.1039/c7cp04473a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effect of glassy formation on water transport in sucrose aerosol droplets is evaluated from characteristic time in a vacuum FTIR experiment.
Collapse
Affiliation(s)
- Yun Zhang
- Institute of Chemical Physics
- Beijing Institute of Technology
- Beijing 100081
- People's Republic of China
| | - Chen Cai
- Institute of Chemical Physics
- Beijing Institute of Technology
- Beijing 100081
- People's Republic of China
- Department of Atmospheric and Oceanic Sciences
| | - Shu-Feng Pang
- Institute of Chemical Physics
- Beijing Institute of Technology
- Beijing 100081
- People's Republic of China
| | | | - Yun-Hong Zhang
- Institute of Chemical Physics
- Beijing Institute of Technology
- Beijing 100081
- People's Republic of China
| |
Collapse
|
10
|
Wiebenga-Sanford BP, DiVerdi J, Rithner CD, Levinger NE. Nanoconfinement's Dramatic Impact on Proton Exchange between Glucose and Water. J Phys Chem Lett 2016; 7:4597-4601. [PMID: 27779880 DOI: 10.1021/acs.jpclett.6b01651] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Glucose nanoconfined by solubilization in water-containing AOT (sodium bis(2-ethylhexyl) sulfosuccinate) reverse micelles has been investigated using 1H NMR. NMR spectra reveal well-defined signals for the glucose hydroxyl groups that suggest slow chemical exchange between them and the water hydroxyl groups. Using the EXSY (ZZ-exchange) method, the chemical exchange rate from water to glucose hydroxyl groups was measured for glucose in reverse micelles as a function of size (water pool diameter of ∼1-5 nm) at 25 °C. The chemical exchange rates observed in the nanoconfined interior are dramatically slower (5-20 times) than those observed for glucose in bulk aqueous solution at the same concentration as the micelle interior. Exchange rate constants are calculated via a mechanism that accounts for these observations, and implications of these results are presented and discussed.
Collapse
Affiliation(s)
| | - Joseph DiVerdi
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523-1872, United States
| | - Christopher D Rithner
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523-1872, United States
| | - Nancy E Levinger
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523-1872, United States
| |
Collapse
|
11
|
The nature of nonfreezing water in carbohydrate polymers. Carbohydr Polym 2016; 150:353-8. [DOI: 10.1016/j.carbpol.2016.04.119] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 11/19/2022]
|
12
|
Price HC, Mattsson J, Murray BJ. Sucrose diffusion in aqueous solution. Phys Chem Chem Phys 2016; 18:19207-16. [PMID: 27364512 PMCID: PMC5044753 DOI: 10.1039/c6cp03238a] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 06/21/2016] [Indexed: 12/02/2022]
Abstract
The diffusion of sugar in aqueous solution is important both in nature and in technological applications, yet measurements of diffusion coefficients at low water content are scarce. We report directly measured sucrose diffusion coefficients in aqueous solution. Our technique utilises a Raman isotope tracer method to monitor the diffusion of non-deuterated and deuterated sucrose across a boundary between the two aqueous solutions. At a water activity of 0.4 (equivalent to 90 wt% sucrose) at room temperature, the diffusion coefficient of sucrose was determined to be approximately four orders of magnitude smaller than that of water in the same material. Using literature viscosity data, we show that, although inappropriate for the prediction of water diffusion, the Stokes-Einstein equation works well for predicting sucrose diffusion under the conditions studied. As well as providing information of importance to the fundamental understanding of diffusion in binary solutions, these data have technological, pharmaceutical and medical implications, for example in cryopreservation. Moreover, in the atmosphere, slow organic diffusion may have important implications for aerosol growth, chemistry and evaporation, where processes may be limited by the inability of a molecule to diffuse between the bulk and the surface of a particle.
Collapse
Affiliation(s)
- Hannah C. Price
- School of Earth and Environment , University of Leeds , Leeds , UK .
| | - Johan Mattsson
- School of Physics and Astronomy , University of Leeds , Leeds , UK .
| | | |
Collapse
|
13
|
Shalaev E, Soper AK. Water in a Soft Confinement: Structure of Water in Amorphous Sorbitol. J Phys Chem B 2016; 120:7289-96. [PMID: 27379700 DOI: 10.1021/acs.jpcb.6b06157] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structure of water in 70 wt % sorbitol-30 wt % water mixture is investigated by wide-angle neutron scattering (WANS) as a function of temperature. WANS data are analyzed using empirical potential structure refinement to obtain the site-site radial distribution functions (RDFs). Orientational structure of water is represented using OW-OW-OW triangles distributions and a tetrahedrality parameter, q, while water-water correlation function is used to estimate size of water clusters. Water structure in the sorbitol matrix is compared with that of water confined in nanopores of MCM41. The results indicate the existence of voids in the sorbitol matrix with the length scale of approximately 5 Å, which are filled by water. At 298 K, positional water structure in these voids is similar to that of water in MCM41, whereas there is a difference in the tetrahedral (orientational) arrangement. Cooling to 213 K strengthens tetrahedrality, with the orientational order of water in sorbitol becoming similar to that of confined water in MCM41 at 210 K, whereas further cooling to 100 K does not introduce any additional changes in the tetrahedrality. The results obtained allow us to propose, for the first time, that such confinement of water in a sorbitol matrix is the main reason for the lack of ice formation in this system.
Collapse
Affiliation(s)
| | - Alan K Soper
- ISIS Facility, STFC Rutherford Appleton Laboratory , Harwell Campus, Didcot, Oxon OX11 OQX, United Kingdom
| |
Collapse
|
14
|
Davies JF, Wilson KR. Raman Spectroscopy of Isotopic Water Diffusion in Ultraviscous, Glassy, and Gel States in Aerosol by Use of Optical Tweezers. Anal Chem 2016; 88:2361-6. [DOI: 10.1021/acs.analchem.5b04315] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James F. Davies
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94611, United States
| | - Kevin R. Wilson
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94611, United States
| |
Collapse
|
15
|
Fan H, Tinsley MR, Goulay F. Effect of Relative Humidity on the OH-Initiated Heterogeneous Oxidation of Monosaccharide Nanoparticles. J Phys Chem A 2015; 119:11182-90. [PMID: 26473757 DOI: 10.1021/acs.jpca.5b06364] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Hanyu Fan
- Department
of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Mark R. Tinsley
- Department
of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Fabien Goulay
- Department
of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| |
Collapse
|
16
|
Price HC, Mattsson J, Zhang Y, Bertram AK, Davies JF, Grayson JW, Martin ST, O'Sullivan D, Reid JP, Rickards AMJ, Murray BJ. Water diffusion in atmospherically relevant α-pinene secondary organic material. Chem Sci 2015; 6:4876-4883. [PMID: 28717493 PMCID: PMC5502394 DOI: 10.1039/c5sc00685f] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 06/04/2015] [Indexed: 12/11/2022] Open
Abstract
We report the first direct measurements of water diffusion coefficients in secondary organic aerosol.
Secondary organic material (SOM) constitutes a large mass fraction of atmospheric aerosol particles. Understanding its impact on climate and air quality relies on accurate models of interactions with water vapour. Recent research shows that SOM can be highly viscous and can even behave mechanically like a solid, leading to suggestions that particles exist out of equilibrium with water vapour in the atmosphere. In order to quantify any kinetic limitation we need to know water diffusion coefficients for SOM, but this quantity has, until now, only been estimated and has not yet been measured. We have directly measured water diffusion coefficients in the water soluble fraction of α-pinene SOM between 240 and 280 K. Here we show that, although this material can behave mechanically like a solid, at 280 K water diffusion is not kinetically limited on timescales of 1 s for atmospheric-sized particles. However, diffusion slows as temperature decreases. We use our measured data to constrain a Vignes-type parameterisation, which we extend to lower temperatures to show that SOM can take hours to equilibrate with water vapour under very cold conditions. Our modelling for 100 nm particles predicts that under mid- to upper-tropospheric conditions radial inhomogeneities in water content produce a low viscosity surface region and more solid interior, with implications for heterogeneous chemistry and ice nucleation.
Collapse
Affiliation(s)
- Hannah C Price
- School of Earth and Environment , University of Leeds , Leeds , LS2 9JT , UK . ; ; Tel: +44-(0)113-343-9085 ; Tel: +44(0)-0113-343-2887
| | - Johan Mattsson
- School of Physics and Astronomy , University of Leeds , Leeds , LS2 9JT , UK
| | - Yue Zhang
- School of Engineering and Applied Sciences , Harvard University , Cambridge , MA 02138 , USA
| | - Allan K Bertram
- Department of Chemistry , University of British Columbia , Vancouver , BC , Canada V6T 1Z1
| | - James F Davies
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK
| | - James W Grayson
- Department of Chemistry , University of British Columbia , Vancouver , BC , Canada V6T 1Z1
| | - Scot T Martin
- School of Engineering and Applied Sciences , Harvard University , Cambridge , MA 02138 , USA.,Department of Earth and Planetary Sciences , Harvard University , Cambridge , MA 02138 , USA
| | - Daniel O'Sullivan
- School of Earth and Environment , University of Leeds , Leeds , LS2 9JT , UK . ; ; Tel: +44-(0)113-343-9085 ; Tel: +44(0)-0113-343-2887
| | - Jonathan P Reid
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK
| | | | - Benjamin J Murray
- School of Earth and Environment , University of Leeds , Leeds , LS2 9JT , UK . ; ; Tel: +44-(0)113-343-9085 ; Tel: +44(0)-0113-343-2887
| |
Collapse
|
17
|
Ohtake S, Shalaev E. Effect of Water on the Chemical Stability of Amorphous Pharmaceuticals: I. Small Molecules. J Pharm Sci 2013; 102:1139-54. [DOI: 10.1002/jps.23440] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 10/10/2012] [Accepted: 12/11/2012] [Indexed: 11/07/2022]
|
18
|
van der Sman RGM, Meinders MBJ. Moisture diffusivity in food materials. Food Chem 2012; 138:1265-74. [PMID: 23411242 DOI: 10.1016/j.foodchem.2012.10.062] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 10/01/2012] [Indexed: 11/30/2022]
Abstract
This paper investigates whether moisture diffusion can be predicted for food materials. We focus especially on mixtures of glucose homopolymers and water. The predictions are based on three theories: (1) the Darken relation, linking the mutual diffusivity to the self diffusivities, (2) the generalised Stokes-Einstein relation for the solute self diffusivity, and (3) the free volume theory for water self diffusivity. Using literature data obtained for the whole class of glucose homopolymer, we show that these theories predict the moisture diffusivity for the whole range of volume fractions, from zero to one, and a broad range of temperatures. Furthermore, we show that the theories equally holds for other hydrophilic biopolymers one finds in food. In the concentrated regime, all experimental data collapse to a single curve. This universal behaviour arises because these biopolymers form a hydrogen bonded network, where water molecules move via rearrangement of the free volume.
Collapse
Affiliation(s)
- R G M van der Sman
- Agrotechnology and Food Sciences Group, Wageningen University & Research, The Netherlands.
| | | |
Collapse
|
19
|
Luthra SA, Shalaev EY, Medek A, Hong J, Pikal MJ. Chemical Stability of Amorphous Materials: Specific and General Media Effects in the Role of Water in the Degradation of Freeze-Dried Zoniporide. J Pharm Sci 2012; 101:3110-23. [DOI: 10.1002/jps.23128] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 02/02/2012] [Accepted: 03/02/2012] [Indexed: 11/12/2022]
|