scholarly journals Thermo-Responsive Polymer Brushes with Side Graft Chains: Relationship Between Molecular Architecture and Underwater Adherence

2019 ◽  
Vol 20 (24) ◽  
pp. 6295
Author(s):  
Ugo Sidoli ◽  
Hisaschi T. Tee ◽  
Ivan Raguzin ◽  
Jakob Mühldorfer ◽  
Frederik R. Wurm ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Bulk Solution ◽  
Molecular Architecture ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Grafted Polymer ◽  
Flat Surfaces ◽  
Underwater Adhesion ◽  
Lcst Behavior ◽  
Responsive Polymer

During the last few decades, wet adhesives have been developed for applications in various fields. Nonetheless, key questions such as the most suitable polymer architecture as well as the most suitable chemical composition remain open. In this article, we investigate the underwater adhesion properties of novel responsive polymer brushes with side graft chain architecture prepared using “grafting through” approach on flat surfaces. The incorporation in the backbone of thermo-responsive poly(N-isopropylacrylamide) (PNIPAm) allowed us to obtain LCST behavior in the final layers. PNIPAm is co-polymerized with poly(methyl ethylene phosphate) (PMEP), a poloyphosphoester. The final materials are characterized studying the surface-grafted polymer as well as the polymer from the bulk solution, and pure PNIPAm brush is used as reference. PNIPAm-g-PMEP copolymers retain the responsive behavior of PNIPAm: when T > LCST, a clear switching of properties is observed. More specifically, all layers above the critical temperature show collapse of the chains, increased hydrophobicity and variation of the surface charge even if no ionizable groups are present. Secondly, effect of adhesion parameters such as debonding rate and contact time is studied. Thirdly, the reversibility of the adhesive properties is confirmed by performing adhesion cycles. Finally, the adhesive properties of the layers are studied below and above the LCST against hydrophilic and hydrophobic substrates.

Multi-Stimuli-Responsive Mesoporous Membranes and Effect of Molecular Architecture on Thermo- and pH-Responsive Behavior of the grafted Block Copolymer brushes

2019 ◽  
Author(s):  
Yanchun Tang ◽  
Kohzo Ito ◽  
Hideaki Yokoyama
Keyword(s):  
Polymer Brushes ◽  
Diblock Copolymers ◽  
Neutron Reflectivity ◽  
Molecular Architecture ◽  
Stimuli Responsive ◽  
Responsive Polymer ◽  
The Matrix ◽  
Stable Part ◽  
Copolymer Brushes ◽  
Mesoporous Membranes

In this study, we prepared ultrafiltration membranes with a decoupled responses of filtration property to temperature and pH. The membrane preparation method was developed based on our previous work. We utilized methanol-supercritical carbon dioxide (methanol-scCO<sub>2</sub>) selective swelling method to introduce nanopores to block copolymers containing poly(diethylene glycol) methyl ether methacrylate (PMEO<sub>2</sub>MA), poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) and polystyrene (PS) blocks. Formation of the mesoporous barrier layer with PS being the mechanically stable part of the matrix was driven by selective swelling of the PMEO<sub>2</sub>MA-b-PDMAEMA domains. Due to the selective swelling of PMEO<sub>2</sub>MA or PDMAEMA domains to introduce pores, the interior of the pores are covered with PMEO<sub>2</sub>MA or PDMAEMA blocks after pore formation. The PMEO<sub>2</sub>MA-b-PDMAEMA polymer brushes are naturally attached on the pore walls and worked as functional gates. PMEO<sub>2</sub>MA is a non-toxic, neutral thermo-responsive polymer with LCST at 26 ᴼC. PDMAEMA is a typical weak polyelectrolyte with pK<sub>a</sub> value at 7.0-7.5 and also a thermo-responsive polymer revealed a LCST of 20-80 °C in aqueous solution. Therefore, these membranes were expected to have multi dimensions as function of the combination of temperature and pH. Moreover, to understand the detail of the temperature and pH depended conformation transitions of PMEO<sub>2</sub>MA-b-PDMAEMA brushes, those diblock copolymers were end-tethered on flat substrates and analyzed via neutron reflectivity (NR).

Multi-Stimuli-Responsive Mesoporous Membranes and Effect of Molecular Architecture on Thermo- and pH-Responsive Behavior of the grafted Block Copolymer brushes

2019 ◽  
Author(s):  
Yanchun Tang ◽  
Kohzo Ito ◽  
Hideaki Yokoyama
Keyword(s):  
Polymer Brushes ◽  
Diblock Copolymers ◽  
Neutron Reflectivity ◽  
Molecular Architecture ◽  
Stimuli Responsive ◽  
Responsive Polymer ◽  
The Matrix ◽  
Stable Part ◽  
Copolymer Brushes ◽  
Mesoporous Membranes

In this study, we prepared ultrafiltration membranes with a decoupled responses of filtration property to temperature and pH. The membrane preparation method was developed based on our previous work. We utilized methanol-supercritical carbon dioxide (methanol-scCO<sub>2</sub>) selective swelling method to introduce nanopores to block copolymers containing poly(diethylene glycol) methyl ether methacrylate (PMEO<sub>2</sub>MA), poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) and polystyrene (PS) blocks. Formation of the mesoporous barrier layer with PS being the mechanically stable part of the matrix was driven by selective swelling of the PMEO<sub>2</sub>MA-b-PDMAEMA domains. Due to the selective swelling of PMEO<sub>2</sub>MA or PDMAEMA domains to introduce pores, the interior of the pores are covered with PMEO<sub>2</sub>MA or PDMAEMA blocks after pore formation. The PMEO<sub>2</sub>MA-b-PDMAEMA polymer brushes are naturally attached on the pore walls and worked as functional gates. PMEO<sub>2</sub>MA is a non-toxic, neutral thermo-responsive polymer with LCST at 26 ᴼC. PDMAEMA is a typical weak polyelectrolyte with pK<sub>a</sub> value at 7.0-7.5 and also a thermo-responsive polymer revealed a LCST of 20-80 °C in aqueous solution. Therefore, these membranes were expected to have multi dimensions as function of the combination of temperature and pH. Moreover, to understand the detail of the temperature and pH depended conformation transitions of PMEO<sub>2</sub>MA-b-PDMAEMA brushes, those diblock copolymers were end-tethered on flat substrates and analyzed via neutron reflectivity (NR).

scholarly journals 3D-printing on textiles – an investigation on adhesion properties of the produced composite materials

2021 ◽  
Vol 28 (6) ◽  
Author(s):  
Maryna Gorlachova ◽  
Boris Mahltig
Keyword(s):  
3D Printing ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Practical Applications ◽  
3D Print ◽  
3D Objects ◽  
Textile Fabrics ◽  
Polylactide Acid ◽  
Polyamide 6.6 ◽  
Textile Sector

AbstractThe actual paper is related to adhesive properties of 3D objects printed on cotton textile fabrics. For practical applications of 3D prints in the textile sector, the adhesion of the printed object on the textile substrate is an important issue. In the current study, two different types of polymers are printed on cotton – polylactide acid (PLA) and polyamide 6.6 (Nylon). Altogether six cotton fabrics differing in structure, weight and thickness are evaluated. Also, the effect of washing and enzymatic desizing is investigated. For printing parameters, best results are gained for elevated process temperatures, intermediate printing speed and low Z-distance between printing head and substrate. Also, a textile treatment by washing and desizing can improve the adhesion of an afterwards applied 3D print. The presented results are quite useful for future developments of 3D printing applications on textile substrates, e.g. to implement new decorative features or protective functions.

Immobilization of Silver Nanoparticles on Responsive Polymer Brushes

2008 ◽  
Vol 41 (8) ◽  
pp. 2874-2879 ◽  
Author(s):  
Smrati Gupta ◽  
Petra Uhlmann ◽  
Mukesh Agrawal ◽  
Severine Chapuis ◽  
Ulrich Oertel ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Polymer Brushes ◽  
Responsive Polymer

scholarly journals Conformation Study of Dual Stimuli-Responsive Core-Shell Diblock Polymer Brushes

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1084
Author(s):  
Kaimin Chen ◽  
Lan Cao ◽  
Ying Zhang ◽  
Kai Li ◽  
Xue Qin ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Core Shell ◽  
Stimuli Responsive ◽  
Research Topics ◽  
Design And Synthesis ◽  
Mild Conditions ◽  
The Core ◽  
Responsive Polymer ◽  
Stimuli Responsive Polymer ◽  
Shed Light

Stimuli-responsive nanoparticles are among the most popular research topics. In this study, two types of core-shell (polystyrene with a photoiniferter (PSV) as the core and diblock as the shell) polymer brushes (PSV@PNIPA-b-PAA and PSV@PAA-b-PNIPA) were designed and prepared using surface-initiated photoiniferter-mediated polymerization (SI-PIMP). Moreover, their pH- and temperature-stimuli responses were explored by dynamic light scattering (DLS) and turbidimeter under various conditions. The results showed that the conformational change was determined on the basis of the competition among electrostatic repulsion, hydrophobic interaction, hydrogen bonding, and steric hindrance, which was also confirmed by protein adsorption experiments. These results are not only helpful for the design and synthesis of stimuli-responsive polymer brushes but also shed light on controlled protein immobilization under mild conditions.

scholarly journals Experimental and Numerical Peeling Investigation on Aged Multi-Layer Anti-Shatter Safety Films (ASFs) for Structural Glass Retrofit

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 162
Author(s):  
Silvana Mattei ◽  
Luca Cozzarini ◽  
Chiara Bedon
Keyword(s):  
Young Modulus ◽  
Adhesive Layer ◽  
Experimental Program ◽  
Fe Model ◽  
Structural Glass ◽  
Adhesive Properties ◽  
Test Protocol ◽  
Adhesion Properties ◽  
The Impact ◽  
Pet Films

Anti-shatter safety films (ASFs) are often used for structural glass applications. The goal is to improve the response of monolithic elements and prevent fragments from shattering. Thus, the main reason behind their use is the possibility to upgrade safety levels against the brittle failure of glass and minimize the number of possible injuries. However, the impact response of glass elements bonded with Polyethylene terephthalate (PET)-films and pressure sensitive adhesives (PSAs) still represents a research topic of open discussion. Major challenges derive from material characterization and asymmetrical variability under design loads and ageing. In particular, the measurement of interface mechanical characteristics for the adhesive layer in contact with glass is a primary parameter for the ASF choice optimization. For this reason, the present paper presents an experimental campaign aimed at calibrating some basic mechanical parameters that provide the characterization of constitutive models, such as tensile properties (yielding stress and Young modulus) for PET-film and adhesive properties for PSA (energy fracture and peel force). In doing so, both tensile tests for PET-films and peeling specimens are taken into account for a commercially available ASF, given that the peeling test protocol is one of most common methods for the definition of adhesion properties. Moreover, an extensive calibration of the Finite Element (FE) model is performed in order to conduct a parametric numerical analysis of ASF bonded glass solutions. Furthermore, a Kinloch approach typically used to determine the fracture energy of a given tape by considering a variable peel angle, is also adopted to compare the outcomes of calibration analyses and FE investigations on the tested specimens. Finally, a study of the effect of multiple aspects is also presented. The results of the experimental program and the following considerations confirm the rate dependence and ageing dependence in peel tests.

scholarly journals Production of modified adhesive composites based on EVA and modified PE

2020 ◽  
pp. 45-47
Author(s):  
M. D. Sizova ◽  
A. N. Zelenetsky ◽  
V. Ya. Ivolgin
Keyword(s):  
Maleic Anhydride ◽  
Polymer Matrix ◽  
Morphological Changes ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
High Adhesion

An adhesive based on EVA and LDPE is developed which can be used up to 60°C. It was modified by polyisocyanate fragments of a grafted and reticulate nature for structural and morphological changes of the polymer matrix and improvement of physical, mechanical and adhesive properties. For additional compatibilization of the components, LDPE modified with maleic anhydride (MA) was used. High adhesion properties of the obtained composites were confirmed.

scholarly journals Justification of sorption composite usage on the basis of nanodisperse silica for sepsis prevention in complex treatment of purulent-inflammatory processes

2019 ◽  
Vol 41 part 3 (2) ◽  
pp. 45-50
Author(s):  
O. A. Viltsaniuk ◽  
P. V. Belyaev ◽  
T. P. Osolodchenko ◽  
O. O. Viltsaniuk
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Properties ◽  
Statistical Processing ◽  
Toxic Substances ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
E Coli ◽  
Adhesion Ability ◽  
Treatment And Prevention ◽  
Inflammatory Processes

Introduction. The problem of purulent-inflammatory processes treatment and the prevention of sepsis remains one of the most pressing problems of surgery.Purpose of the study. Is to estimate the effectiveness of sorption composition with antimicrobial properties on the basis of nanodisperse silica on the adhesive properties of microorganisms and to substantiate the expediency of its use for the purulent and inflammatory processes treatment and prevention of sepsis.Materials and methods.To determine the antimicrobial activity and the influence of the antiseptics of decasan, myramistin, ethonium, chlorhexidine and the sorption on the microorganisms adhesion properties composition was used the method of diffusion in agar of the museum strains of microorganisms S. Aureus ATCC 25923, E. Coli ATCC 25922, R. Vulgaris 4636, R. Aureginosa ATCC 27853, S. AIbicans 855/653, SI. Perfringens 28, Peptostreptococcus anaerobicus 22, Bacteroides fragilis 13/83, and clinical strains of S. Aureus, R. Aeuroginosa, E. Coli. Adhesive properties of microorganisms were studied according to the Brillis method et al. (1986) with the subsequent statistical processing of the data.Results. Studies have shown that antiseptics have high antimicrobial activity and reduce the adhesion ability of microorganisms. But the use of only antiseptics or only antibiotics for the purification of purulent foci can lead to toxins absorption and tissue decay products from purulent foci. That processes could be the trigger mechanism for sepsis development. The sorption composition is able to reduce the adhesive activity of bacteria, allows to absorb toxic substances from pathological foci, what preventing their resorption and thereby prevent the development of sepsis.Conclusions. The composition made from sorbents and antiseptics is not inferior to antimicrobial activity to antiseptics, which can reduce the virulence of bacteria, by reducing their adhesive activity, and absorb toxins of microorganisms and tissue decomposition products on their surface, thus prevent their absorption, which will prevent the purulent-inflammatory process progression and sepsis development.Keywords: sorption composition, nanodisperse silica, antiseptics, adhesive properties of microorganisms, prevention of sepsis.

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