1
|
Shen Z, Wang T, Luo J, Liu R, Ngai T, Sun G. Unraveling the Complexities of Silica Nanoparticle Adsorption onto Polymer Latexes in Pickering Emulsion Polymerization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 39158702 DOI: 10.1021/acs.langmuir.4c02219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/20/2024]
Abstract
Incorporating unmodified silica nanoparticles onto polymer latexes to fabricate aqueous polymer dispersions without relying on electrostatic attraction during the Pickering emulsion polymerization process still faces challenges. For negatively charged silica nanoparticles to successfully adsorb onto polymer latexes, particularly in an anionic initiator emulsion polymerization system, they have remained elusive without the use of auxiliary monomers and cationic initiators. This study investigates various experimental parameters, such as emulsion polymerization temperature, monomer solubility, salt concentration, and cation type, to elucidate the factors influencing the adsorption of unmodified silica nanoparticles in Pickering emulsion polymerization. While poly(methyl methacrylate) (PMMA)/SiO2 hybrid latexes can be obtained under pH conditions of 5-6 and at temperatures of 65 °C or below, the loading rate of silica nanoparticles decreases as the reaction temperature increases, resulting in bare PMMA latexes without silica nanoparticle adsorption at temperatures exceeding 70 °C. Introducing styrene (St) into the monomer mixture with methyl methacrylate in a ratio of up to 10 wt % leads to a gradual decrease in silica nanoparticle loading rate, from 27.3 to 8.2 wt %, attributed to the low solubility of St in water. Furthermore, the presence of sodium ions (Na+) is found to be crucial for silica nanoparticle adsorption onto PMMA latexes, as the sodium ions have a stabilizing effect on both the silica nanoparticles and the silica nanoparticle-armored latexes. These findings highlight the complex nature of Pickering emulsion polymerization in the presence of unmodified silica nanoparticles, demonstrating that the loading rate of silica nanoparticles onto polymer latexes is influenced by various factors. These insights pave the way for developing aqueous polymer dispersions with high silica nanoparticle loading rates onto polymer latexes, which is a desirable trait in the coating industry.
Collapse
Affiliation(s)
- Zekai Shen
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122 Jiangsu, China
| | - Tianheng Wang
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122 Jiangsu, China
| | - Jing Luo
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122 Jiangsu, China
| | - Ren Liu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122 Jiangsu, China
| | - To Ngai
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122 Jiangsu, China
- Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, 999077 Special Administrative Region, China
| | - Guanqing Sun
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122 Jiangsu, China
| |
Collapse
|
2
|
Jacob S, Boddu SHS, Bhandare R, Ahmad SS, Nair AB. Orodispersible Films: Current Innovations and Emerging Trends. Pharmaceutics 2023; 15:2753. [PMID: 38140094 PMCID: PMC10747242 DOI: 10.3390/pharmaceutics15122753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/06/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Orodispersible films (ODFs) are thin, mechanically strong, and flexible polymeric films that are designed to dissolve or disintegrate rapidly in the oral cavity for local and/or systemic drug delivery. This review examines various aspects of ODFs and their potential as a drug delivery system. Recent advancements, including the detailed exploration of formulation components, such as polymers and plasticizers, are briefed. The review highlights the versatility of preparation methods, particularly the solvent-casting production process, and novel 3D printing techniques that bring inherent flexibility. Three-dimensional printing technology not only diversifies active compounds but also enables a multilayer approach, effectively segregating incompatible drugs. The integration of nanoparticles into ODF formulations marks a significant breakthrough, thus enhancing the efficiency of oral drug delivery and broadening the scope of the drugs amenable to this route. This review also sheds light on the diverse in vitro evaluation methods utilized to characterize ODFs, ongoing clinical trials, approved marketed products, and recent patents, providing a comprehensive outlook of the evolving landscape of orodispersible drug delivery. Current patient-centric approaches involve developing ODFs with patient-friendly attributes, such as improved taste masking, ease of administration, and enhanced patient compliance, along with the personalization of ODF formulations to meet individual patient needs. Investigating novel functional excipients with the potential to enhance the permeation of high-molecular-weight polar drugs, fragile proteins, and oligonucleotides is crucial for rapid progress in the advancing domain of orodispersible drug delivery.
Collapse
Affiliation(s)
- Shery Jacob
- Department of Pharmaceutical Sciences, College of Pharmacy, Gulf Medical University, Ajman P.O. Box 4184, United Arab Emirates;
| | - Sai H. S. Boddu
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Ajman University, Ajman P.O. Box 346, United Arab Emirates; (S.H.S.B.); (R.B.)
- Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman P.O. Box 346, United Arab Emirates
| | - Richie Bhandare
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Ajman University, Ajman P.O. Box 346, United Arab Emirates; (S.H.S.B.); (R.B.)
- Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman P.O. Box 346, United Arab Emirates
| | - Samiullah Shabbir Ahmad
- Department of Pharmaceutical Sciences, College of Pharmacy, Gulf Medical University, Ajman P.O. Box 4184, United Arab Emirates;
| | - Anroop B. Nair
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa 31982, Saudi Arabia;
| |
Collapse
|
3
|
Slastanova A, Campbell RA, Islas L, Welbourn RJL, R P Webster J, Vaccaro M, Chen M, Robles E, Briscoe WH. Interfacial complexation of a neutral amphiphilic 'tardigrade' co-polymer with a cationic surfactant: Transition from synergy to competition. J Colloid Interface Sci 2022; 606:1064-1076. [PMID: 34487929 DOI: 10.1016/j.jcis.2021.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 07/22/2021] [Accepted: 08/02/2021] [Indexed: 11/24/2022]
Abstract
HYPOTHESIS Neutral amphiphilic PEG-g-PVAc co-polymer (a "tardigrade" polymer consisting of a hydrophilic polyethylene glycol, PEG, backbone with hydrophobic polyvinyl acetate, PVAc, grafts) can form complexes at the air-water interface with cationic dodecyltrimethylammonium bromide (DTAB) via self-assembly. Compared to anionic SDS, cationic DTAB headgroups are expected to interact strongly with the negatively charged OH- groups from the partial dissociation of the PVAc grafts. We anticipate a transition from synergistic to competitive behaviour, which is expected to be dependent on the surfactant structural characteristics and concentration. EXPERIMENTS DTAB/PEG-g-PVAc mixtures were investigated using a combination of dynamic and equilibrium surface tension measurements, neutron reflectivity (NR) at the air-water interface, and foaming tests. We varied the concentrations of both the DTAB (0.05 to 5 critical micelle concentration, cmc) and that of PEG-g-PVAc (0.2 and 2 critical aggregation concentration, cac). FINDINGS Our results show that the interfacial interactions between DTAB and PEG-g-PVAc were both synergistic and antagonistic, depending sensitively on the surfactant concentration. At DTAB concentrations below its cmc, a pronounced cooperative adsorption behaviour was likely driven by the hydrophobic interactions between the DTAB tail and the PVAc grafts and the attraction between the DTAB headgroups and the partially dissociated -O- groups in the partially hydrolysed PVAc grafts, forming a mixed layer. This synergistic adsorption behaviour transitioned to a competitive adsorption behaviour at DTAB concentrations above its cmc, leading to polymer-surfactant partition, forming a "hanging" polymer layer underlying a surfactant monolayer at the interface. We postulate that DTAB/PEG-g-PVAc complexation in the bulk contributed to partial depletion of the mixture from the interface. We therefore consider this polymer/surfactant system to be a moderately interacting system at the air-water interface. No discernible differences in the foaming behaviour were observed between the DTAB/PEG-g-PVAc systems and the pure surfactant. Our results suggest that surfactant headgroup characteristics (particularly charges) were crucial in determining the structure and composition of polymer-surfactant complexes at the air-water interface, as well as the foamability and foam stability, whilst the coexistence of the synergistic and competitive adsorption behaviour is attributed to the unique architecture of the tardigrade polymer with amphiphilicity and partial charge, facilitating different surfactant-polymer interactions at different DTAB concentrations.
Collapse
Affiliation(s)
- Anna Slastanova
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Richard A Campbell
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PT, UK; Institut Laue-Langevin, 71 Avenue des Martyrs, CS20156, Grenoble 38042, France
| | - Luisa Islas
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Rebecca J L Welbourn
- ISIS Facility, STFC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK
| | - John R P Webster
- ISIS Facility, STFC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK
| | - Mauro Vaccaro
- Procter & Gamble, Temselaan 100, 1853 Strombeek-Bever, Brussels, Belgium
| | - Meng Chen
- Procter & Gamble Beijing Innovation Centre, 35 Yu'an Rd, Shunyi District, Beijing, China
| | - Eric Robles
- Household Care Analytical, Procter & Gamble Newcastle Innovation Centre, Whitley Road, Longbenton, Newcastle NE12 9TS, UK
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| |
Collapse
|
4
|
Molecular diffusion in ternary poly(vinyl alcohol) solutions. Front Chem Sci Eng 2021. [DOI: 10.1007/s11705-021-2121-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractThe diffusion kinetics of a molecular probe—rhodamine B—in ternary aqueous solutions containing poly(vinyl alcohol), glycerol, and surfactants was investigated using fluorescence correlation spectroscopy and dynamic light scattering. We show that the diffusion characteristics of rhodamine B in such complex systems is determined by a synergistic effect of molecular crowding and intermolecular interactions between chemical species. The presence of glycerol has no noticeable impact on rhodamine B diffusion at low concentration, but significantly slows down the diffusion of rhodamine B above 3.9% (w/v) due to a dominating steric inhibition effect. Furthermore, introducing surfactants (cationic/nonionic/anionic) to the system results in a decreased diffusion coefficient of the molecular probe. In solutions containing nonionic surfactant, this can be explained by an increased crowding effect. For ternary poly(vinyl alcohol) solutions containing cationic or anionic surfactant, surfactant—polymer and surfactant—rhodamine B interactions alongside the crowding effect of the molecules slow down the overall diffusivity of rhodamine B. The results advance our insight of molecular migration in a broad range of industrial complex formulations that incorporate multiple compounds, and highlight the importance of selecting the appropriate additives and surfactants in formulated products.
Collapse
|
5
|
Han GR, Jang H, Ki H, Lee H, Kim MG. Reagent Filming for Universal Point-of-Care Diagnostics. SMALL METHODS 2021; 5:e2100645. [PMID: 34928024 DOI: 10.1002/smtd.202100645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/14/2021] [Indexed: 06/14/2023]
Abstract
Simplifying assays while maintaining the robustness of reagents is a challenge in diagnostics. This problem is exacerbated when translating quality diagnostic assays to developing countries that lack resources and infrastructure such as trained health workers, high-end equipment, and cold-chain systems. To solve this problem, in this study, a simple solution that films assay reagents to simplify the operation of diagnostic assays and preserve the stability of diagnostic reagents without using cold chains is presented. A polyvinyl-alcohol-based water-soluble film is used to encapsulate premeasured and premixed reagents. The reagent film, produced through a simple and scalable cast-drying process, provides a glassy inner matrix with abundant hydroxyl groups that can stabilize various reagents (ranging from chemicals to biological materials) by restricting molecular mobility and generating hydrogen bonds. The reagent film is applied to an enzymatic glucose assay, a high-sensitivity immunoassay for cardiac troponin, and a molecular assay for viral RNA detection, to test its practicability and universal applicability. The film-based assays result in excellent analytical/diagnostic performance and stable long-term reagent storage at elevated temperatures (at 25 or 37 °C, for six months), demonstrating clinical readiness. This technology advances the development and distribution of affordable high-quality diagnostics to resource-limited regions.
Collapse
Affiliation(s)
- Gyeo-Re Han
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Hyungjun Jang
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Hangil Ki
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Hoyeon Lee
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Min-Gon Kim
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| |
Collapse
|
6
|
Impacts of polyols and temperature on the micellization, interaction and thermodynamics behavior of the mixture of tetradecyltrimethylammonium bromide and polyvinyl alcohol. Z PHYS CHEM 2021. [DOI: 10.1515/zpch-2021-3065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Herein, the aggregation manner of the mixture of polyvinyl alcohol (PVA) and tetradecyltrimethylammonium bromide (TTAB) was performed in polyols (glucose, maltose and galactose) media over 300.55–320.55 K temperatures range with 5 K interval through conductivity measurement method. The micelle formation of TTAB + PVA mixture was identified by the assessment of critical micelle concentration (CMC) from the plots of specific conductivity (κ) versus TTAB concentration. The degree of micelle ionization (α), the extent of bound counter ions (β) as well as thermodynamic properties (
Δ
G
m
0
${\Delta}{G}_{m}^{0}$
,
Δ
H
m
0
${\Delta}{H}_{m}^{0}$
and
Δ
S
m
0
${\Delta}{S}_{m}^{0}$
) of TTAB + PVA systems have been estimated. The CMC values reveal that the micelle formation of TTAB + PVA mixture experience an enhancement in the manifestation of polyols. The values of free energy of micellization (
Δ
G
m
0
${\Delta}{G}_{m}^{0}$
) are negative for the TTAB + PVA system in aqueous polyols media, suggesting a spontaneous aggregation phenomenon. The
Δ
H
m
0
${\Delta}{H}_{m}^{0}$
and
Δ
S
m
0
${\Delta}{S}_{m}^{0}$
values of TTAB + PVA systems direct that the PVA molecule interacts with TTAB through the exothermic, ion-dipole, and hydrophobic interactions. The thermodynamic properties of transfer were also determined for the move of TTAB + PVA mixture from H2O to water + polyols mixed solvents. The values of compensation temperature (T
c) and intrinsic enthalpy gain (
Δ
H
m
0
,
∗
${\Delta}{H}_{m}^{0,\ast }$
) were evaluated and discussed for the studied system.
Collapse
|
7
|
Cortés-Morales EC, Rathee VS, Ghobadi A, Whitmer JK. A molecular view of plasticization of polyvinyl alcohol. J Chem Phys 2021; 155:174903. [PMID: 34742193 DOI: 10.1063/5.0065964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although macromolecules such as polymers are in widespread industrial use, pure formulations rarely have precisely the properties new applications demand. Pure polymer is often too brittle and inflexible, necessitating plasticizers to soften or toughen films and bulk polymer materials. In practice, new formulations are developed by extensive trial-and-error methods, as no general molecular explanations exist for the mechanism of plasticization to aid in determining the optimal structure and concentration of plasticizers. Here, through atomistic molecular simulations augmented with advanced sampling techniques, we develop an atomic-level picture of the processes in plasticization by directly calculating free energies that govern the interaction between polymers and small-molecule plasticizers. This work focuses on the influence of two common plasticizer molecules-glycerol and sorbitol-interacting with polyvinyl alcohol (PVA), a frequently used component of polymer films. In particular, we focus on conformational and hydrogen bond structure changes induced in globules of PVA by the plasticizer molecules, with the hypothesis that hydrogen bonding plays a role in the incorporation of these plasticizers into PVA and, thus, in the observed mechanical properties. While we focus on nanoscopic systems, we observe distinct preferences in the conformational free energy that can be connected to the performance of polymer materials at laboratory and industrial scales. This work presents a new molecular perspective from which effective plasticizers can be developed and presents a firm basis from which important analyses of plasticization in complex chemical environments relevant to industry may be developed.
Collapse
Affiliation(s)
- Ernesto C Cortés-Morales
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Vikramjit S Rathee
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Ahmad Ghobadi
- Corporate R & D, Data and Modeling Sciences, The Procter and Gamble Company, Mason, Ohio 45040, USA
| | - Jonathan K Whitmer
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| |
Collapse
|
8
|
Litwinowicz M, Rogers S, Caruana A, Kinane C, Tellam J, Thompson R. Tuning the Bulk and Surface Properties of PDMS Networks through Cross-Linker and Surfactant Concentration. Macromolecules 2021; 54:9636-9648. [PMID: 34720190 PMCID: PMC8552438 DOI: 10.1021/acs.macromol.1c01600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/16/2021] [Indexed: 11/29/2022]
Abstract
The elastic modulus and hydrophilicity of cross-linked poly(dimethylsiloxane) (PDMS) are tunable via cross-linker concentration and the addition of a simple surfactant, C12E4, before curing. However, the surfactant concentration, [C12E4], reduces the elastic modulus (73% lower for 6.3% w/w) because it reduces the extent of curing. This is likely because the hygroscopic surfactant results in water poisoning of the catalyst. Three distinct time-dependent hydrophilicity profiles were identified using water contact angle analysis with [C12E4] determining which profile was observed. This indicates the concentration-dependent phase behavior of C12E4 within PDMS films. Changes in phase behavior were identified using small-angle neutron scattering (SANS) and a compatibility study. No surface excess or surface segregation of surfactant was observed at the PDMS-air interface. However, a surface excess revealed by neutron reflectivity against a D2O interface indicates that the increase in hydrophilicity results from the migration of C12E4 to the film interface when exposed to water.
Collapse
Affiliation(s)
| | - Sarah Rogers
- STFC
ISIS Facility, Rutherford Appleton Laboratories, Chilton, Didcot OX11 0QX, United Kingdom
| | - Andrew Caruana
- STFC
ISIS Facility, Rutherford Appleton Laboratories, Chilton, Didcot OX11 0QX, United Kingdom
| | - Christy Kinane
- STFC
ISIS Facility, Rutherford Appleton Laboratories, Chilton, Didcot OX11 0QX, United Kingdom
| | - James Tellam
- STFC
ISIS Facility, Rutherford Appleton Laboratories, Chilton, Didcot OX11 0QX, United Kingdom
| | - Richard Thompson
- Department
of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| |
Collapse
|
9
|
Gibson CP, Litwinowicz MA, Tellam JP, Welbourn RJL, Skoda MWA, Claussen J, Thompson RL. Water-Resistant Surface Modification of Hydrophobic Polymers with Water-Soluble Surfactant Additives. Polymers (Basel) 2021; 13:polym13193407. [PMID: 34641221 PMCID: PMC8512660 DOI: 10.3390/polym13193407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 11/16/2022] Open
Abstract
Water-soluble nonionic surfactant, pentaethylene glycol monododecyl ether, C12E5, spontaneously blooms to the surface of spin-cast hydrophobic polyisoprenes, generating hydrophilic surfaces. This system provides a simple model for hydrophilic chemical modification of rubbery polymers that demonstrates surprisingly rich, complex, and unexpected behaviour. The vertical depth profiles were quantified using neutron reflectometry (NR) using a novel procedure to account for undulations in the film thickness. Surface properties were characterized using contact angle analysis and atomic force microscopy (AFM). Despite the low surface tension of the toluene solvent used in film preparation and the low surface energy of the polyisoprene (PI) matrix, NR depth profiles revealed clear evidence of surfactant segregation. This surface layer was typically thicker than a monolayer, but incomplete, yet was remarkably stable with respect to dissolution, even when exposed to hundreds of thousands of times the volume of water required to dissolve all the surfactant on the surface. Despite the apparent resistance to removal from the surface, water exposure does alter the subsequent wettability of the surface, with a hydrophilic-to-hydrophobic transition occurring after rinsing. Complementary AFM images of these C12E5/cis-PI films showed unexpected strand-like features on the surface of the film, which we attribute to a non-uniform lateral distribution of some of the surfactant. This surface structure becomes more evident after rinsing, and it appears that there are two distinct populations of surfactant on the PI film surface. We conclude that some of the bloomed surfactant exists as layers, which are relatively inert with respect to rinsing or surface modification, and some is laterally inhomogeneous. This latter population is primarily responsible for surface wetting behaviour but is not detected by specular NR.
Collapse
Affiliation(s)
- Colin P. Gibson
- Department of Chemistry, Durham University, Durham DH1 3LE, UK; (C.P.G.); (M.A.L.)
| | | | - James P. Tellam
- STFC ISIS Neutron and Muon Source, Rutherford Appleton Laboratories, Didcot OX11 0QX, UK; (J.P.T.); (R.J.L.W.); (M.W.A.S.)
| | - Rebecca J. L. Welbourn
- STFC ISIS Neutron and Muon Source, Rutherford Appleton Laboratories, Didcot OX11 0QX, UK; (J.P.T.); (R.J.L.W.); (M.W.A.S.)
| | - Maximilian W. A. Skoda
- STFC ISIS Neutron and Muon Source, Rutherford Appleton Laboratories, Didcot OX11 0QX, UK; (J.P.T.); (R.J.L.W.); (M.W.A.S.)
| | - Jan Claussen
- Procter & Gamble, German Innovation Center, Sulzbacher Str. 40, 65824 Schwalbach am Taunus, Germany;
| | - Richard L. Thompson
- Department of Chemistry, Durham University, Durham DH1 3LE, UK; (C.P.G.); (M.A.L.)
- Correspondence: ; Tel.: +44-191-334-2139
| |
Collapse
|
10
|
Baglioni M, Sekine FH, Ogura T, Chen SH, Baglioni P. Nanostructured fluids for polymeric coatings removal: Surfactants affect the polymer glass transition temperature. J Colloid Interface Sci 2021; 606:124-134. [PMID: 34390987 DOI: 10.1016/j.jcis.2021.07.078] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 11/19/2022]
Abstract
HYPOTHESIS Nanostructured fluids (NSFs) based on water, organic solvents and surfactants are a valid alternative to the use of neat unconfined organic solvents for polymer coatings removal in art conservation. The physico-chemical processes underpinning their cleaning effectiveness in terms of swelling/dewetting of polymer films were identified as key in this context. The role of surfactants on polymers' dewetting was considered to be mainly restricted to the lowering of interfacial tensions. However, recent experiments evidenced that surfactants have an important role in swelling polymer films. EXPERIMENTS Five different amphiphiles were selected, namely: sodium dodecylsulfate, dimethyldodecyl amine oxide, hexaoxyethylene decyl ether (C9-11E6), pentadecaoxyethylene dodecyl ether (C12E15), and methyoxypentadecaoxyethylene dodecanoate (C11COE15CH3). They were combined with a carefully selected organic solvents' mixture (1-butanol/butanone/dimethyl carbonate) to formulate new NSFs, differing for the surfactant only, and used to perform cleaning tests on surfaces coated with Paraloid B72® and Primal AC33®. Here for the first time, polymer swelling induced by surfactants was quantified and correlated with the glass transition temperature of the two polymers by differential scanning calorimetry, before and after the exposure to the fluids. Confocal laser scanning microscopy and small-angle X-ray scattering provided additional insights on the interaction mechanism. FINDINGS Nonionics were proven more efficient than zwitterionic/ionic amphiphiles in the polymer swelling, and, overall, methyoxy pentadecaoxyethylene dodecanoate resulted the most effective among the selected surfactants. A direct relation between the effect of surfactants on the polymers' glass transition temperature and cleaning capacity was established. This finding, fundamental to understand the interaction mechanism between NSFs and polymer coatings or paint layers, is key to achieve a selective, effective and complete removal of polymer coatings, as recently shown in the removal of vandalism and over-paintings from street art.
Collapse
Affiliation(s)
- Michele Baglioni
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, Sesto Fiorentino (FI) 50019, Italy
| | - Felipe Hidetomo Sekine
- NIKKOL GROUP Nikko Chemicals Co., Ltd, 1-4-8, Nihonbashi-Bakurocho, Chuo-ku, Tokyo 103-0002, Japan
| | - Taku Ogura
- NIKKOL GROUP Nikko Chemicals Co., Ltd, 1-4-8, Nihonbashi-Bakurocho, Chuo-ku, Tokyo 103-0002, Japan; NIKKOL GROUP Cosmos Technical Center Co., Ltd, 3-24-3 Hasune, Itabashi-ku, Tokyo 174-0046, Japan; Research Institute for Science & Technology, Tokyo University of Science, 2641, Noda-shi, Chiba, Yamazaki 278-8510, Japan
| | - Sow-Hsin Chen
- Department of Nuclear Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 24-107, Cambridge, MA 02139, USA
| | - Piero Baglioni
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, Sesto Fiorentino (FI) 50019, Italy; Department of Nuclear Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 24-107, Cambridge, MA 02139, USA.
| |
Collapse
|
11
|
Liu X, Counil C, Shi D, Mendoza-Ortega EE, Vela-Gonzalez AV, Maestro A, Campbell RA, Krafft MP. First quantitative assessment of the adsorption of a fluorocarbon gas on phospholipid monolayers at the air/water interface. J Colloid Interface Sci 2021; 593:1-10. [DOI: 10.1016/j.jcis.2021.02.073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/15/2021] [Accepted: 02/16/2021] [Indexed: 12/19/2022]
|
12
|
Pushp P, Bhaskar R, Kelkar S, Sharma N, Pathak D, Gupta MK. Plasticized poly(vinylalcohol) and poly(vinylpyrrolidone) based patches with tunable mechanical properties for cardiac tissue engineering applications. Biotechnol Bioeng 2021; 118:2312-2325. [PMID: 33675237 DOI: 10.1002/bit.27743] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/31/2020] [Accepted: 02/25/2021] [Indexed: 12/20/2022]
Abstract
Polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) are the two most investigated biopolymers for various tissue engineering applications. However, their poor tensile strength renders them unsuitable for cardiac tissue engineering (CTE). In this study, we developed and evaluated PVA-PVP-based patches, plasticized with glycerol or propylene glycol (0.1%-0.4%; v:v), for their application in CTE. The cardiac patches were evaluated for their physico-chemical (weight, thickness, folding endurance, FT-IR, and swelling behavior) and mechanical properties. The optimized patches were characterized for their ability to support in vitro attachment, viability, proliferation, and beating behavior of neonatal mouse cardiomyocytes (CMs). In vivo evaluation of the cardiac patches was done under the subcutaneous skin pouch and heart of rat models. Results showed that the optimized molar ratio of PVA:PVP with plasticizers (0.3%; v-v) resulted in cardiac patches, which were dry at room temperature and had desirable folding endurance of at least 300, a tensile strength of 6-23 MPa and, percentage elongation at break of more than 250%. Upon contact with phosphate-buffered saline, these PVA-PVP patches formed hydrogel patches having the tensile strength of 1.3-3.0 MPa. The patches supported the attachment, viability, and proliferation of primary neonatal mouse CMs and were nonirritant and noncorrosive to cardiac cells. In vivo transplantation of cardiac patches into a subcutaneous pouch and on the heart of rat models revealed them to be biodegradable, biocompatible, and safe for use in CTE applications.
Collapse
Affiliation(s)
- Pallavi Pushp
- Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Odisha, India.,Department of Biotechnology, Institute of Engineering and Technology, Bundelkhand University, Jhansi, Uttar Pradesh, India
| | - Rakesh Bhaskar
- Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Odisha, India
| | - Samruddhi Kelkar
- Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Odisha, India
| | - Neelesh Sharma
- Division of Veterinary Medicine, Faculty of Veterinary Science, Sher-e-Kashmir University of Agriculture Science and Technology of Jammu, Jammu, India
| | - Devendra Pathak
- Department of Veterinary Anatomy, College of Veterinary Sciences, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - Mukesh Kumar Gupta
- Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Odisha, India
| |
Collapse
|
13
|
Schulz M, Smith RW, Sear RP, Brinkhuis R, Keddie JL. Diffusiophoresis-Driven Stratification of Polymers in Colloidal Films. ACS Macro Lett 2020; 9:1286-1291. [PMID: 35638630 DOI: 10.1021/acsmacrolett.0c00363] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The molecular composition of polymer blend surfaces defines properties such as adhesion, wetting, gloss, and biocompatibility. The surface composition often differs from the bulk because of thermodynamic effects or modification. Mixtures of colloids and linear polymers in a common solvent are often used to deposit films for use in encapsulants, inks, coatings, and adhesives. However, means to control the nonequilibrium surface composition are lacking for these systems. Here we show how the surface composition and hydrophilicity of a film deposited from a bimodal mixture of linear polymers and colloids in water can be adjusted simply by varying the evaporation rate. Ion beam analysis was used to quantify the extent of stratification of the linear polymers near the surface, and the results are in agreement with a recent diffusiophoretic model. Because our approach to stratification relies solely on diffusiophoresis, it is widely applicable to any system deposited from colloids and nonadsorbing polymers in solution as a means to tailor surface properties.
Collapse
Affiliation(s)
- Malin Schulz
- Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
| | - Richard W Smith
- Surrey Ion Beam Centre, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
| | - Richard P Sear
- Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
| | | | - Joseph L Keddie
- Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
| |
Collapse
|
14
|
Fong R, Squillace O, Reynolds CD, Cooper JFK, Dalgliesh RM, Tellam J, Courchay F, Thompson RL. Segregation of Amine Oxide Surfactants in PVA Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4795-4807. [PMID: 32271588 PMCID: PMC7304907 DOI: 10.1021/acs.langmuir.0c00084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/08/2020] [Indexed: 06/11/2023]
Abstract
The vertical depth distributions of amine oxide surfactants, N,N-dimethyldodecyl amine N-oxide (DDAO) and N,N-dimethyltetradecyl amine N-oxide (DTAO), in poly(vinyl alcohol) (PVA) films were explored using neutron reflectometry (NR). In both binary and plasticized films, the two deuterated surfactants formed a single monolayer on the film surface with the remaining surfactant homogeneously distributed throughout the bulk of the film. Small-angle neutron scattering and mechanical testing revealed that these surfactants acted like plasticizers in the bulk, occupying the amorphous regions of PVA and reducing its glass-transition temperature. NR revealed little impact of plasticizer (glycerol) incorporation on the behavior of these surfactants in PVA. The surfactant molecular area in the segregated monolayer was smaller for DTAO than for DDAO, indicating that the larger molecule was more densely packed at the surface. Surface tension was used to assess the solution behavior of these surfactants and the effect of glycerol incorporation. Determination of molecular area of each surfactant on the solution surface revealed that the structures of the surface monolayers are remarkably consistent when water is placed by the solid PVA. Incorporation of glycerol caused a decrease of molecular area for DDAO and increase in molecular area for DTAO both in solution and in PVA. This suggests that the head group interactions, which normally limit the minimum area per adsorbed molecule, are modified by the length of the alkyl tail.
Collapse
Affiliation(s)
- Rebecca
J. Fong
- Department
of Chemistry, Durham University, Science Site, Durham DH1
3LE, United Kingdom
- Procter
& Gamble, Newcastle Innovation Centre, Whitley Road, Newcastle-upon-Tyne, NE12 9TS, United Kingdom
| | - Ophélie Squillace
- Department
of Chemistry, Durham University, Science Site, Durham DH1
3LE, United Kingdom
- School
of Chemical Engineering, University of Birmingham, SW Campus, Birmingham B15 2TT, United
Kingdom
| | - Carl D. Reynolds
- Department
of Chemistry, Durham University, Science Site, Durham DH1
3LE, United Kingdom
- School
of Chemistry, University of Birmingham, University Road West, Birmingham B15 2TT, United Kingdom
| | | | - Robert M. Dalgliesh
- ISIS Neutron
and Muon Source, Rutherford Appleton Laboratories, Chilton, Didcot, OX11
0QX, United Kingdom
| | - James Tellam
- Rutherford
Appleton Laboratories, Chilton, Didcot, OX11 0QX, United
Kingdom
| | - Florence Courchay
- Procter
& Gamble, Brussels Innovation Center, Temselaan 100, 1853 Strombeek Bever, Brussels, Belgium
| | - Richard L. Thompson
- Department
of Chemistry, Durham University, Science Site, Durham DH1
3LE, United Kingdom
| |
Collapse
|
15
|
Tasche J, Sabattié EFD, Thompson RL, Campana M, Wilson MR. Oligomer/Polymer Blend Phase Diagram and Surface Concentration Profiles for Squalane/Polybutadiene: Experimental Measurements and Predictions from SAFT-γ Mie and Molecular Dynamics Simulations. Macromolecules 2020; 53:2299-2309. [PMID: 32308214 PMCID: PMC7161083 DOI: 10.1021/acs.macromol.9b02155] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 02/12/2020] [Indexed: 01/16/2023]
Abstract
The compatibility and surface behavior of squalane-polybutadiene mixtures are studied by experimental cloud point and neutron reflectivity measurements, statistical associating fluid theory (SAFT), and molecular dynamics (MD) simulations. A SAFT-γ Mie model is shown to be successful in capturing the cloud point curves of squalane-polybutadiene and squalane-cis-polybutadiene binary mixtures, and the same SAFT-γ Mie model is used to develop a thermodynamically consistent top-down coarse-grained force field to describe squalane-polybutadiene. Coarse-grained molecular dynamics simulations are performed to study surface behavior for different concentrations of squalane, with the system exhibiting surface enrichment and a wetting transition. Simulated surface profiles are compared with those obtained by fitting to neutron reflectivity data obtained from thin films composed of deuterated squalane (d-sq)-polybutadiene. The presented top-down parametrization methodology is a fast and thermodynamically reliable approach for predicting properties of oligomer-polymer mixtures, which can be challenging for either theory or MD simulations alone.
Collapse
Affiliation(s)
- Jos Tasche
- Department of Chemistry, Durham University, Lower Mountjoy, Stockton Road, Durham DH1 3LE, United Kingdom
| | - Elise F D Sabattié
- Department of Chemistry, Durham University, Lower Mountjoy, Stockton Road, Durham DH1 3LE, United Kingdom
| | - Richard L Thompson
- Department of Chemistry, Durham University, Lower Mountjoy, Stockton Road, Durham DH1 3LE, United Kingdom
| | - Mario Campana
- Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
| | - Mark R Wilson
- Department of Chemistry, Durham University, Lower Mountjoy, Stockton Road, Durham DH1 3LE, United Kingdom
| |
Collapse
|
16
|
Squillace O, Fong R, Shepherd O, Hind J, Tellam J, Steinke NJ, Thompson RL. Influence of PVAc/PVA Hydrolysis on Additive Surface Activity. Polymers (Basel) 2020; 12:polym12010205. [PMID: 31947559 PMCID: PMC7023474 DOI: 10.3390/polym12010205] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 12/29/2022] Open
Abstract
This aims to establish design rules for the influence of complex polymer matrices on the surface properties of small molecules. Here, we consider the dependence of the surface behaviour of some model additives on polymer matrix hydrophobicity. With stoichiometric control over hydrolysis, we generate systematic changes in matrix chemistry from non-polar, hydrophobic PVAc to its hydrolysed and hydrophilic analogue, PVA. With the changing degree of hydrolysis (DH), the behaviour of additives can be switched in terms of compatibility and surface activity. Sorbitol, a polar sugar-alcohol of inherently high surface energy, blooms to the surface of PVAc, forming patchy domains on surfaces. With the increasing DH of the polymer matrix, its surface segregation decreases to the point where sorbitol acts as a homogeneously distributed plasticiser in PVA. Conversely, and despite its low surface energy, octanoic acid (OA) surprisingly causes the increased wettability of PVAc. We attribute these observations to the high compatibility of OA with PVAc and its ability to reorient upon exposure to water, presenting a hydrophilic COOH-rich surface. The surfactant sodium dodecyl sulfate (SDS) does not show such a clear dependence on the matrix and formed wetting layers over a wide range of DH. Interestingly, SDS appears to be most compatible with PVAc at intermediate DH, which is consistent with the amphiphilic nature of both species under these conditions. Thus, we show that the prediction of the segregation is not simple and depends on multiple factors including hydrophobicity, compatibility, blockiness, surface energy, and the mobility of the components.
Collapse
Affiliation(s)
- Ophélie Squillace
- Department of Chemistry, Durham University, Stockton Road, Durham DH1 3LE, UK; (R.F.); (O.S.); (R.L.T.)
- Correspondence: ; Tel.: +44(0)-7999-284328
| | - Rebecca Fong
- Department of Chemistry, Durham University, Stockton Road, Durham DH1 3LE, UK; (R.F.); (O.S.); (R.L.T.)
| | - Oliver Shepherd
- Department of Chemistry, Durham University, Stockton Road, Durham DH1 3LE, UK; (R.F.); (O.S.); (R.L.T.)
| | - Jasmine Hind
- STFC ISIS Facility, Rutherford Appleton Laboratories, Chilton, Didcot OX11 0QX, UK; (J.H.); (J.T.); (N.-J.S.)
| | - James Tellam
- STFC ISIS Facility, Rutherford Appleton Laboratories, Chilton, Didcot OX11 0QX, UK; (J.H.); (J.T.); (N.-J.S.)
| | - Nina-Juliane Steinke
- STFC ISIS Facility, Rutherford Appleton Laboratories, Chilton, Didcot OX11 0QX, UK; (J.H.); (J.T.); (N.-J.S.)
| | - Richard L. Thompson
- Department of Chemistry, Durham University, Stockton Road, Durham DH1 3LE, UK; (R.F.); (O.S.); (R.L.T.)
| |
Collapse
|
17
|
Fong RJ, Robertson A, Mallon PE, Thompson RL. The Impact of Plasticizer and Degree of Hydrolysis on Free Volume of Poly(vinyl alcohol) Films. Polymers (Basel) 2018; 10:polym10091036. [PMID: 30960961 PMCID: PMC6403818 DOI: 10.3390/polym10091036] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 09/07/2018] [Accepted: 09/12/2018] [Indexed: 01/06/2023] Open
Abstract
The effect of plasticizer species and the degree of hydrolysis (DH) on the free volume properties of poly(vinyl alcohol) (PVA) were studied using positron annihilation lifetime spectroscopy. Both glycerol and propylene glycol caused an increase in the free volume cavity radius, although exhibited distinct plasticization behavior, with glycerol capable of occupying existing free volume cavities in the PVA to some extent. The influence of water, normally present in PVA film under atmospheric conditions, was also isolated. Water added significantly to the measured free volume cavity radius in both plasticized and pure PVA matrices. Differences in plasticization behavior can be attributed to the functionality of each plasticizing additive and its hydrogen bonding capability. The increase in cavity radii upon plasticizer loading shows a qualitative link between the free volume of voids and the corresponding reduction in Tg and crystallinity. Cavity radius decreases with increasing DH, due to PVA network tightening in the absence of acetate groups. This corresponds well with the higher Tg observed in the resin with the higher DH. DH was also shown to impact the plasticization of PVA with glycerol, indicating that the larger cavities—created by the weaker hydrogen bonding acetate groups—are capable of accommodating glycerol molecules with negligible effect on the cavity dimensions.
Collapse
Affiliation(s)
- Rebecca J Fong
- Department of Chemistry, Durham University, Mountjoy Site, Durham DH1 3LE, UK.
| | - Alexander Robertson
- Department of Chemistry, Durham University, Mountjoy Site, Durham DH1 3LE, UK.
| | - Peter E Mallon
- Department of Chemistry and Polymer Science, University of Stellenbosch, Matieland 7602, Western Cape, South Africa.
| | - Richard L Thompson
- Department of Chemistry, Durham University, Mountjoy Site, Durham DH1 3LE, UK.
| |
Collapse
|
18
|
Abstract
The analysis of thin films is of central importance for functional materials, including the very large and active field of nanomaterials. Quantitative elemental depth profiling is basic to analysis, and many techniques exist, but all have limitations and quantitation is always an issue. We here review recent significant advances in ion beam analysis (IBA) which now merit it a standard place in the analyst's toolbox. Rutherford backscattering spectrometry (RBS) has been in use for half a century to obtain elemental depth profiles non-destructively from the first fraction of a micron from the surface of materials: more generally, "IBA" refers to the cluster of methods including elastic scattering (RBS; elastic recoil detection, ERD; and non-Rutherford elastic backscattering, EBS), nuclear reaction analysis (NRA: including particle-induced gamma-ray emission, PIGE), and also particle-induced X-ray emission (PIXE). We have at last demonstrated what was long promised, that RBS can be used as a primary reference technique for the best traceable accuracy available for non-destructive model-free methods in thin films. Also, it has become clear over the last decade that we can effectively combine synergistically the quite different information available from the atomic (PIXE) and nuclear (RBS, EBS, ERD, NRA) methods. Although it is well known that RBS has severe limitations that curtail its usefulness for elemental depth profiling, these limitations are largely overcome when we make proper synergistic use of IBA methods. In this Tutorial Review we aim to briefly explain to analysts what IBA is and why it is now a general quantitative method of great power. Analysts have got used to the availability of the large synchrotron facilities for certain sorts of difficult problems, but there are many much more easily accessible mid-range IBA facilities also able to address (and often more quantitatively) a wide range of otherwise almost intractable thin film questions.
Collapse
Affiliation(s)
- Chris Jeynes
- University of Surrey Ion Beam Centre, Guildford, GU2 7XJ, England, UK
| | - Julien L Colaux
- University of Surrey Ion Beam Centre, Guildford, GU2 7XJ, England, UK
| |
Collapse
|
19
|
Briddick A, Fong RJ, Sabattié EFD, Li P, Skoda MWA, Courchay F, Thompson RL. Blooming of Smectic Surfactant/Plasticizer Layers on Spin-Cast Poly(vinyl alcohol) Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:1410-1418. [PMID: 29293356 DOI: 10.1021/acs.langmuir.7b04046] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The blooming of sodium dodecyl sulfate (SDS) and the influence of plasticizer (glycerol) on the surfactant distribution in poly(vinyl alcohol) (PVA) films have been explored by neutron reflectometry (NR) and ion beam analysis techniques. When in binary films with PVA, deuterated SDS (d25-SDS) forms a surface excess corresponding to a wetting layer of the surfactant molecules at the film surface. The magnitude of this surface excess increased significantly in the presence of the plasticizer, and the surfactant was largely excluded from the PVA subphase. NR revealed smectic nanostructures for both SDS and glycerol components within this surface excess in plasticized films. This combined layer comprises surfactant lamellae, separated by interstitial glycerol-rich layers, which is only formed in the plasticized films and persists throughout the surface excess. Atomic force microscopy micrographs of the film surfaces revealed platelike structures in the plasticized PVA, which were consistent with the rigid defects in the surfactant-rich lamellae. The formation of these structures arises from the synergistic surface segregation of SDS and glycerol, evidenced by surface tensiometry. Cloud point analysis of bulk samples indicates a transition at ∼55% water content, below which phase separation occurs in ternary films. This transition is likely to be necessary to form the thick wetting layer observed and therefore indicates that film components remain mobile beyond this point in the drying process.
Collapse
Affiliation(s)
- Arron Briddick
- Department of Chemistry, Durham University , Science Site, Durham DH1 3LE, U.K
| | - Rebecca J Fong
- Department of Chemistry, Durham University , Science Site, Durham DH1 3LE, U.K
| | - Elise F D Sabattié
- Department of Chemistry, Durham University , Science Site, Durham DH1 3LE, U.K
| | - Peixun Li
- STFC ISIS Facility, Rutherford Appleton Laboratories , Chilton, Didcot OX110QX, U.K
| | - Maximilian W A Skoda
- STFC ISIS Facility, Rutherford Appleton Laboratories , Chilton, Didcot OX110QX, U.K
| | - Florence Courchay
- Procter&Gamble, Brussels Innovation Center (BIC) , Temselaan 100, 1853 Strombeek Bever, Brussels, Belgium
| | - Richard L Thompson
- Department of Chemistry, Durham University , Science Site, Durham DH1 3LE, U.K
| |
Collapse
|
20
|
Tian H, Liu D, Yao Y, Ma S, Zhang X, Xiang A. Effect of Sorbitol Plasticizer on the Structure and Properties of Melt Processed Polyvinyl Alcohol Films. J Food Sci 2017; 82:2926-2932. [PMID: 29165805 DOI: 10.1111/1750-3841.13950] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 09/06/2017] [Accepted: 09/15/2017] [Indexed: 01/23/2023]
Abstract
Poly (vinyl alcohol) (PVA) possesses wide applications as food packaging materials, but is difficult to melt process for its strong inter/intra hydrogen bonding. In this work, flexible PVA films with different content of sorbitol plasticizers were prepared by melt processing with the assistance of water. And the influence of sorbitol plasticizer content on the crystallinity, optical transparency, water-retaining capability, mechanical properties, thermal stability and oxygen and water permeability were investigated. The results indicated that sorbitol dramatically improved the melt processing ability of PVA. Sorbitol could interact with PVA to form strong hydrogen bonding interactions, which would decrease the original hydrogen bonding of the matrix, resulting in the decrease of crystallinity degrees. The glass transition, melting and crystallization peak temperatures decreased with the increase of sorbitol. All the films exhibited fine optical transparency. The water retaining capability were improved with the increase of sorbitol. Especially, an increase in elongation at break and decrease in Young's modulus and tensile strength were observed indicating good plasticizing effect of sorbitol on PVA films. In addition, the PVA films prepared in this work exhibited fine barrier properties against oxygen and water, suggesting wide application potential as packaging materials.
Collapse
Affiliation(s)
- Huafeng Tian
- School of Material and Mechanical Engineering, Beijing Technology and Business Univ., Beijing, 100048, China.,State Key Lab. for Modification of Chemical Fibers and Polymer Materials, Donghua Univ., Shanghai, China
| | - Di Liu
- School of Material and Mechanical Engineering, Beijing Technology and Business Univ., Beijing, 100048, China
| | - Yuanyuan Yao
- School of Material and Mechanical Engineering, Beijing Technology and Business Univ., Beijing, 100048, China
| | - Songbai Ma
- School of Material and Mechanical Engineering, Beijing Technology and Business Univ., Beijing, 100048, China
| | - Xing Zhang
- School of Material and Mechanical Engineering, Beijing Technology and Business Univ., Beijing, 100048, China
| | - Aimin Xiang
- School of Material and Mechanical Engineering, Beijing Technology and Business Univ., Beijing, 100048, China
| |
Collapse
|
21
|
Sabattié EFD, Tasche J, Wilson MR, Skoda MWA, Hughes A, Lindner T, Thompson RL. Predicting oligomer/polymer compatibility and the impact on nanoscale segregation in thin films. SOFT MATTER 2017; 13:3580-3591. [PMID: 28443905 DOI: 10.1039/c7sm00048k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Compatibility between oligomers and polymers was systematically assessed using differential scanning calorimetry (DSC) and was correlated with similarity in saturation and solubility parameter. These measurements enabled validation of detailed volume of mixing calculations using Statistical Association Fluid Theory (SAFT-γ Mie) and molecular dynamics (MD) simulations, which can be used to predict behaviour beyond the experimentally accessible conditions. These simulations confirmed that squalane is somewhat more compatible with poly(isoprene), "PI" than poly(butadiene), "PB", and further enabled prediction of the temperature dependence of compatibility. Surface and interfacial segregation of a series of deuterated oligomers was quantified in rubbery polymer films: PI, PB and hydrogenated poly(isoprene) "hPI". A striking correlation was established between surface wetting transition and mixtures of low compatibility, such as oligo-dIB in PB or PI. Segregation was quantified normal to the surface by ion beam analysis and neutron reflectometry and in some cases lateral segregation was observable by AFM. While surface segregation is driven by disparity in molecular weight in highly compatible systems this trend reverses as critical point is approached, and surface segregation increases with increasing oligomer molecular weight.
Collapse
Affiliation(s)
- Elise F D Sabattié
- Department of Chemistry, Durham University, Science Site, Durham DH1 3LE, UK. and Procter & Gamble, German Innovation Center (GIC), Sulzbacher Str. 40-50, 65824, Schwalbach am Taunus, Germany
| | - Jos Tasche
- Department of Chemistry, Durham University, Science Site, Durham DH1 3LE, UK.
| | - Mark R Wilson
- Department of Chemistry, Durham University, Science Site, Durham DH1 3LE, UK.
| | - Maximilian W A Skoda
- STFC ISIS Facility, Rutherford Appleton Laboratories, Chilton, Didcot, OX110QX, UK
| | - Arwel Hughes
- STFC ISIS Facility, Rutherford Appleton Laboratories, Chilton, Didcot, OX110QX, UK
| | - Torsten Lindner
- Procter & Gamble, German Innovation Center (GIC), Sulzbacher Str. 40-50, 65824, Schwalbach am Taunus, Germany
| | - Richard L Thompson
- Department of Chemistry, Durham University, Science Site, Durham DH1 3LE, UK.
| |
Collapse
|