scholarly journals Porous Layer-by-Layer Films Assembled Using Polyelectrolyte Blend to Control Wetting Properties

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2116
Author(s):  
Choonghyun Sung ◽  
Yejin Heo
Keyword(s):  
Porous Layer ◽  
Contact Angles ◽  
Control Surface ◽  
Layer By Layer ◽  
Ethylene Imine ◽  
Water Contact ◽  
Wetting Properties ◽  
Lbl Films ◽  
Poly Ethylene ◽  
Surface Morphologies

Porous layer-by-layer (LbL) films have been employed for the implementation of superwetting surfaces, but they are limited to the LbL films consisting of only two oppositely charged polyelectrolytes. In this study, LbL films were assembled using a cationic polymer blend of branched poly(ethylene imine) (BPEI) and poly(allylamine hydrochloride) (PAH), and anionic poly(acrylic acid); they were then acid-treated at pH 1.8–2.0 to create a porous structure. The films of 100% BPEI exhibited a relatively smooth surface, whereas those of the 100% PAH exhibited porous surfaces. However, various surface morphologies were obtained when BPEI and PAH were blended. When coated with fluorinated silane, films with 50% and 100% PAH exhibited relatively higher water contact angles (WCAs). In particular, films with 50% PAH exhibited the highest WCA of 140–150° when treated at pH 1.8. These fluorinated films were further infused with lubricant oil to determine their feasibility as slippery surfaces. The water and oil sliding angles were in the range of 10–20° and 5–10°, respectively. Films prepared with the BPEI/PAH blend showed lower water slide angles than those prepared with 100% BPEI or PAH. Acid treatment of LbL films assembled using a polyelectrolyte blend can effectively control surface morphologies and can potentially be applied in superwetting.

scholarly journals Synthesis of amphiphilic ABA triblock oligomer via ATRP and its surface properties

2017 ◽  
Vol 95 (5) ◽  
pp. 605-611 ◽  
Author(s):  
Lei Wang ◽  
Shaoqing Wen ◽  
Zhanxiong Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Microphase Separation ◽  
Gel Permeation Chromatography ◽  
Contact Angles ◽  
Chemical Compositions ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Poly Ethylene ◽  
Magnetic Resonances

A series of novel amphiphilic ABA-type poly(tridecafluorooctylacrylate)-poly(ethylene glycol)-poly(tridecafluorooctylacrylate) (henceforth referred to as p-TDFA-PEG-p-TDFA) triblock oligomers were successfully synthesized via atom transfer radical polymerization (ATRP) using well-defined Br-PEG-Br as macroinitiator and copper as catalyst. The block oligomers were characterized by Fourier transform infrared (FTIR) spectroscopy and 1H and 19F nuclear magnetic resonances (NMR). Gel permeation chromatography (GPC) showed that the block oligomers have been obtained with narrow molecular weight distributions of 1.22–1.33. X-ray photoelectron spectroscopy (XPS) was carried out to confirm the attachment of p-TDFA-PEG-p-TDFA onto the silicon substrate, together with the chemical compositions of p-TDFA-PEG-p-TDFA. The wetabilities of the oligomer films were measured by water contact angles (CAs). Water CAs of p-TDFA-PEG-p-TDFA film were measured and their morphologies were tested by atomic force microscopy (AFM). The result showed that the CAs of the oligomer films, which possess fluoroalkyl groups assembled on the outer surface, increase after heating due to the migration of fluoroalkyl groups and the resulted microphase separation of the p-TDFA-PEG-p-TDFA.

Surface Modification of PEOT/PBT Membrane with Silk Fibroin Anchoring and its Potential Application in Artificial Salivary Gland Construct

2012 ◽  
Vol 538-541 ◽  
pp. 52-59
Author(s):  
Jie Zhu ◽  
Ming Shi Li ◽  
Li Qun Wang ◽  
Xiao Lin Zhu
Keyword(s):  
Salivary Gland ◽  
Silk Fibroin ◽  
Potential Application ◽  
Contact Angles ◽  
Water Contact ◽  
Polar Groups ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Surface Modified

We reported the preparation of surface modified poly (ethylene oxide terephthalate) - poly (butylene terephthalate) membrane by the method of silk fibroin anchoring, namely SF/(PEOT/PBT). Its surface properties were characterized by contact angles and XPS and the biocompatibility of the composite membrane was further evaluated by human salivary epithelial cells (HSG cells) growth in vitro. Results revealed that SF/(PEOT/PBT) possessed the low water contact angle (48.0±3.0°) and immobilized a great amount of fibroin (fibroin surface coverage: 26.39 wt%), which attributed to the formation of polar groups such as hydrosulfide group, sulfonic group, carboxyl and carbonyl ones in the process of SO2 plasma treatment. HSG cells growth in vitro indicated that the silk fibroin anchoring could significantly enhance the biocompatibility of PEOT/PBT membrane, which suggested the potential application of fibroin anchoring PEOT/PBT for clinical HSG cells transplantation in the artificial salivary gland construct.

scholarly journals Bacterial factors influencing adhesion of Pseudomonas aeruginosa strains to a poly(ethylene oxide) brush

Microbiology ◽  
2006 ◽  
Vol 152 (9) ◽  
pp. 2673-2682 ◽  
Author(s):  
Astrid Roosjen ◽  
Henk J. Busscher ◽  
Willem Norde ◽  
Henny C. van der Mei
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ethylene Oxide ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Contact Angles ◽  
Bacterial Strains ◽  
Water Contact ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Brush Coating

Most bacterial strains adhere poorly to poly(ethylene oxide) (PEO)-brush coatings, with the exception of a Pseudomonas aeruginosa strain. The aim of this study was to find factors determining whether P. aeruginosa strains do or do not adhere to a PEO-brush coating in a parallel plate flow chamber. On the basis of their adhesion, a distinction could be made between three adhesive and three non-adhesive strains of P. aeruginosa, while bacterial motilities and zeta potentials were comparable for all six strains. However, water contact angles indicated that the adhesive strains were much more hydrophobic than the non-adhesive strains. Furthermore, only adhesive strains released surfactive extracellular substances, which may be engaged in attractive interactions with the PEO chains. Atomic force microscopy showed that the adhesion energy, measured from the retract curves of a bacterial-coated cantilever from a brush coating, was significantly more negative for adhesive strains than for non-adhesive strains (P<0.001). Through surface thermodynamic and extended-DLVO (Derjaguin, Landau, Verwey, Overbeek) analyses, these stronger adhesion energies could be attributed to acid–base interactions. However, the energies of adhesion of all strains to a brush coating were small when compared with their energies of adhesion to a glass surface. Accordingly, even the adhesive P. aeruginosa strains could be easily removed from a PEO-brush coating by the passage of a liquid–air interface. In conclusion, cell surface hydrophobicity and surfactant release are the main factors involved in adhesion of P. aeruginosa strains to PEO-brush coatings.

SURFACE MODIFICATION OF POLY(VINYLIDENE FLUORIDE) FILMS BY CONTROLLED GRAFTING POLYMER BRUSHES

2005 ◽  
Vol 12 (05n06) ◽  
pp. 709-712 ◽  
Author(s):  
YIWANG CHEN ◽  
DONGMEI LIU ◽  
NING ZHANG
Keyword(s):  
Polymer Brushes ◽  
Vinylidene Fluoride ◽  
Contact Angles ◽  
Linear Increase ◽  
Chain Growth ◽  
Hydroxyl Groups ◽  
Water Contact ◽  
Poly Vinylidene Fluoride ◽  
Surface Hydroxylation ◽  
Poly Ethylene

Controlled grafting of well-defined polymer brushes on the poly(vinylidene fluoride) (PVDF) films was carried out by the surface-initiated Atom Transfer Radical polymerization (ATRP). Surface-initiators were immobilized on the PVDF films by surface hydroxylation and esterification of the surface-tethered hydroxyl groups with 2-bromoisobutyrate bromide. Water contact angles on PVDF films were reduced by surface grafting of poly(ethylene glycol) monomethacrylate (PEGMA) and methyl methacrylate (MMA). Kinetics study revealed a linear increase in the graft concentration of PMMA and PEGMA with the reaction time, indicating that the chain growth from the surface, was consistence with a "controlled" or "living" process.

scholarly journals The Effect of Poly(ethylene glycol) (PEG) Length on the Wettability and Surface Chemistry of PEG-Fluoroalkyl-Modified Polystyrene Diblock Copolymers and Their Two-Layer Films with Elastomer Matrix

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1236 ◽  
Author(s):  
Elisa Guazzelli ◽  
Giancarlo Galli ◽  
Elisa Martinelli
Keyword(s):  
Diblock Copolymers ◽  
Film Surface ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Side Chains ◽  
Water Contact ◽  
Prolonged Contact ◽  
High Enrichment ◽  
Poly Ethylene ◽  
Modified Polystyrene

Diblock copolymers composed of a polystyrene first block and a PEG-fluoroalkyl chain-modified polystyrene second block were synthesized by controlled atom transfer radical polymerization (ATRP), starting from the same polystyrene macroinitiator. The wettability of the polymer film surfaces was investigated by measurements of static and dynamic contact angles. An increase in advancing water contact angle was evident for all the films after immersion in water for short times (10 and 1000 s), consistent with an unusual contraphilic switch of the PEG-fluoroalkyl side chains. Such a contraphilic response also accounted for the retained wettability of the polymer films upon prolonged contact with water, without an anticipated increase in the hydrophilic character. The copolymers were then used as surface-active modifiers of elastomer poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS)-based two-layer films. The elastomeric behavior of the films was varied by using SEBS matrices with different amounts of polystyrene. Whereas the mechanical properties strictly resembled those of the nature of the SEBS matrix, the surface properties were imposed by the additive. The contraphilic switch of the PEG-fluoroalkyl side chains resulted in an exceptionally high enrichment in fluorine of the film surface after immersion in water for seven days.

scholarly journals Effect of the Formation of Ultrathin Selective Layers on the Structure and Performance of Thin-Film Composite Chitosan/PAN Membranes for Pervaporation Dehydration

Membranes ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 153 ◽  
Author(s):  
Mariia Dmitrenko ◽  
Andrey Zolotarev ◽  
Tatiana Plisko ◽  
Katsiaryna Burts ◽  
Vladislav Liamin ◽  
...  
Keyword(s):  
Thin Film ◽  
Optimal Transport ◽  
Interfacial Polymerization ◽  
Contact Angles ◽  
Layer By Layer ◽  
Water Contact ◽  
Selective Layer ◽  
Film Composite ◽  
Thin Film Composite ◽  
And Performance

The aim of the study is to improve the performance of thin-film composite (TFC) membranes with a thin selective layer based on chitosan (CS) via different approaches by: (1) varying the concentration of the CS solution; (2) changing the porosity of substrates from polyacrylonitrile (PAN); (3) deposition of the additional ultrathin layers on the surface of the selective CS layer using interfacial polymerization and layer-by-layer assembly. The developed membranes were characterized by different methods of analyses (SEM and AFM, IR spectroscopy, measuring of water contact angles and porosity). The transport characteristics of the developed TFC membranes were studied in pervaporation separation of isopropanol/water mixtures. It was found that the application of the most porous PAN-4 substrate with combination of formation of an additional polyamide selective layer by interfacial polymerization on the surface of a dense selective CS layer with the subsequent layer-by-layer deposition of five bilayers of poly (sodium 4-styrenesulfonate)/CS polyelectrolyte pair led to the significant improvement of permeance and high selectivity for the entire concentration feed range. Thus, for TFC membrane on the PAN-4 substrate the optimal transport characteristics in pervaporation dehydration of isopropanol (12–90 wt.% water) were achieved: 0.22–1.30 kg/(m2h), 99.9 wt.% water in the permeate.

The Wetting of Insect Cuticles by Water

1955 ◽  
Vol 32 (3) ◽  
pp. 591-617 ◽  
Author(s):  
M. W. HOLDGATE
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Properties ◽  
Surface Composition ◽  
Contact Angles ◽  
Aquatic Species ◽  
Water Contact ◽  
Calliphora Erythrocephala ◽  
Wetting Properties ◽  
Wide Range

1. The water contact angles of insects show a wide range of variation, which is broadly correlated with surface roughness and with habitat. 2. The contact angles of species inhabiting stored products or carrion are greatly modified by contamination. This produces large variations between apparently similar individuals. 3. In terrestrial insects surface roughness increases the contact angles to very large apparent values. Detailed analyses of its effect have been made in the pupa of Tenebrio molitor and the adult Calliphora erythrocephala. In some aquatic insects surface roughness leads to a reduction in the contact angles; this has been studied in the nymph of Anax imperator. 4. Prolonged immersion in water causes a lowering of the contact angles of all the insects examined, and the low angles of many aquatic species may therefore be the direct effect of their environment. In some aquatic species there is evidence of the active maintenance of a large contact angle during life. 5. Changes in contact angle accompany processes of cuticle secretion and will occur at any moult if changes in roughness or habitat take place. 6. The observed variations of surface properties can be explained without assuming any variation in the chemical composition of the cuticle surface. Wetting properties are of little value as indicators of cuticle surface composition. 7. The biological aspects of insect surface properties are briefly discussed.

End-Blocked Silanization of Side-Chain Fluoroalkyl Oligoether and its Surface Properties

2018 ◽  
Vol 71 (11) ◽  
pp. 855
Author(s):  
Lei Wang ◽  
Lei Chen ◽  
Zhanxiong Li
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Side Chain ◽  
Chemical Compositions ◽  
Silicon Substrates ◽  
Water Contact ◽  
Molecular Weights ◽  
Self Assembled ◽  
Surface Morphologies

In this study, three novel side-chain fluoroalkyl oligoethers with different molecular weights were synthesised via a ring-opening reaction of 2,2,3,3,4,4,5,5,5-nonafluoropentyloxirane. The fluorooligoethers were then silanized and characterised by FT-IR,1H, and 19F NMR spectroscopies. These silanlized fluorooligoethers were used to fabricate hydrophobic coatings on silicon substrates, which were pre-treated with O2 plasma, by the method of liquid phase deposition. The chemical compositions and structures of the film surfaces were analysed by X-ray photoelectron spectroscopy and the results showed that silanized fluorooligoethers formed self-assembled films on the silicon wafer. The surface wettability of the coatings was measured by water contact angles. It is noted that the annealing process can improve the hydrophobicity with the highest water contact angle being 115.2 ± 1° and hexadecane contact angle being 67.2 ± 1°. The surface morphologies and roughness of the self-assembled films were measured by atomic force microscopy (AFM), as a result, the surface was found to be rougher with the increment of the molecular weight of the fluorooligoethers.

Sign in / Sign up

Export Citation Format

Share Document