Poly 2-ethyl 2-oxazoline Research Articles

Synergistic control of breath figures on Styrene-Butadiene-Styrene films by poly-2-ethyl-2-oxazoline capped CaCl2 loaded mesoporous silica particles

The addition of hydrophilic components (CaCl2, poly-2-ethyl-2-oxazoline (PEOX) or mesoporous silica particles (MSP)) into Styrene-Butadiene-Styrene (SBS)/chloroform solution was shown to affect the resulting breath figure patterns in terms of pore size, pore shape and order. Honeycomb-patterned porous SBS polymer films were prepared by adding 30 wt% PEOX capped, CaCl2 loaded mesoporous silica particles into SBS solution. The long-range order observed with a pore diameter of ∼3.6 µm in the breath figure pattern at RT and 50–70% RH was attributed to the synergistic contributions of each component. CaCl2 promotes the condensation of water vapor and the nucleation of many water droplets on the polymer solution. When localized in a uniformly swollen layer of PEOX around MSP, easier nucleation together with stabilization of water droplets by MSP and PEOX leads to hexagonally-ordered breath figures. The results demonstrate the addition of hydrophilic components as an easy tool to tune breath figure patterns at relatively low humidity and their synergistic contributions.

Polymer‐Assisted Phase Stable γ‐CsPbI3 Perovskite Film for Self‐Powered and Ultrafast Photodiodes

AbstractLead‐halide perovskite materials have emerged as promising alternatives for optoelectronic applications due to their low‐cost, easily tunable bandgaps, and facile solution‐processability. Despite all their exciting merits, perovskite materials are currently suffering the stability issues, such as moisture and oxygen‐induced rapid degradation and phase transition. In this work, γ phase CsPbI3 perovskite thin films with compact grain boundaries and improved ambient stability are successfully developed via introducing poly‐2‐ethyl‐2‐oxazoline (PEOXA) polymer through an effective bonding between CO double bond in PEOXA with perovskite. The optimized photodetectors with the γ‐CsPbI3:5%PEOXA active thickness as thin as 30 nm have a totally excellent performance with a responsivity of 0.16 A W−1, high detectivity of 2.73 × 1012 Jones, linear dynamic range of over 125 dB, and ultrafast rise/decay time of 13.9/12.7 µs. Moreover, the as‐constructed photodetectors have shown a high stability when maintained under ambient conditions. This work provides new insights for the development of highly stable and efficient perovskite‐based optoelectronics.

Molecular brushes with poly-2-ethyl-2-oxazoline side chains and aromatic polyester backbone manifesting double stimuli responsiveness

Behavior of grafted copolymers composed of aromatic polyester (PAPE) backbone and poly-2-ethyl-2-oxazoline (PEOZ) side chains differing in grafting density in aqueous solutions was studied when heated at various concentrations and pH using static and dynamic light scattering and turbidimetry. Aggregates and individual macromolecules were registered in solutions at all times. It was shown that the aggregates of the brush with higher PEOZ side chains’ grafting density undergo compaction on heating below phase separation, whereas the size of the loose polymer brush aggregates continuously increases with the increase of temperature. Phase separation temperatures of both copolymers decreased with dilution. Strong influence of pH on the thermosensitivity of both samples was shown, the copolymer solubility being decreased with the acidity decrease. The nature of the pH effect is under discussion.

Development of gold-core silica shell nanospheres coated with poly-2-ethyl-oxazoline and β-cyclodextrin aimed for cancer therapy

Cancer is one of the major world public health problems and the currently available treatments are nonspecific and ineffective. This reality highlights the importance of developing novel therapeutic approaches. In this field, multifunctional nanomedicines have the potential to revolutionize the currently available treatments. These unique nanodevices can simultaneously act as therapeutic and imaging agents allowing the real-time monitoring of the nanoparticles biodistribution and the treatment outcome. Among the different nanoparticles, the gold-core silica shell (AuMSS) nanoparticles advantageous physicochemical and biological properties make them promising nanoplatforms for cancer therapy. Nevertheless, their successful application as an effective cancer nanomedicine is limited by the unfavorable pharmacokinetics and uncontrolled release of the therapeutic payloads. Herein, a new polymeric coating for AuMSS nanospheres was developed by combining different ratios (25/75, 50/50 and 75/25) of two materials, Poly-2-ethyl-2-oxazoline (PEOZ) and β-cyclodextrin (β-CD). The surface functionalization of AuMSS nanospheres led to a size increase and to the neutralization of the surface charge. On the other side, the nanoparticles biological performance was improved. The coated AuMSS nanospheres showed an increased cytocompatibility and internalization rate by the HeLa cancer cells. Overall, the obtained data confirm the successful modification of the AuMSS nanospheres with PEOZ and β-CD as well as their promising properties for being applied in cancer therapy.

Development of poly-2-ethyl-2-oxazoline coated gold-core silica shell nanorods for cancer chemo-photothermal therapy.

Develop a new poly-2-ethyl-2-oxazoline (PEOZ)-based coating for doxorubicin-loaded gold-core mesoporous silica shell (AuMSS) nanorods application in cancer chemo-photothermal therapy. PEOZ functionalized AuMSS nanorods were obtained through the chemical grafting on AuMSS of a PEOZ silane derivative. The PEOZ chemical grafting on the surface of AuMSS nanorods allowed the neutralization of nanodevices' surface charge, from -30 to -15mV, which improved nanoparticles' biocompatibility, namely by decreasing the blood hemolysis to negligible levels. In vitro antitumoral studies revealed that the combined treatment mediated by the PEOZ-coated AuMSS nanorods result in a synergistic effect, allowing the complete eradication of cervical cancer cells. The application of the PEOZ coating improves the AuMSS nanorods performance as a multifunctional combinatorial therapy for cervical cancer.

Compatibilization effects in thermoplastic protein/polyester blends

ABSTRACTNovatein thermoplastic protein was extrusion blended with poly(butylene adipate‐co‐terephthalate) (PBAT) in the presence of dual compatibilizers to produce blends with greater energy absorbing properties than pure Novatein. Compatibilizer pairs were Joncryl ADR‐4368 (glycidyl methacrylate‐functionalized) with 2‐methylimidazole (2MI), and poly‐2‐ethyl‐2‐oxazoline (PEOX) with polymeric diphenyl methane diisocyanate (pMDI). Uncompatibilized Novatein/PBAT blends had decreased tensile mechanical properties, attributed to phase separation, and poor interfacial adhesion. PBAT became finely dispersed in both compatibilized systems, but PEOX/pMDI blends showed embrittlement and large Novatein domains, which acted as stress concentrations. Tensile strength and elongation at break for Joncryl/2MI blends did not decrease compared with Novatein, even at 10 wt % PBAT, and impact strength increased threefold. Dynamic mechanical analysis and solvent extraction showed that PBAT coalesced in all systems, at compositions as low as 2 wt %. It was concluded that using Joncryl/2MI as a dual compatibilizer system can successfully produce a morphology that enhances energy absorption during fracture. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45808.

Next‐Generation Polymer Shells for Inorganic Nanoparticles are Highly Compact, Ultra‐Dense, and Long‐Lasting Cyclic Brushes

AbstractCyclic poly‐2‐ethyl‐2‐oxazoline (PEOXA) ligands for superparamagnetic Fe3O4 nanoparticles (NPs) generate ultra‐dense and highly compact shells, providing enhanced colloidal stability and bio‐inertness in physiological media. When linear brush shells fail in providing colloidal stabilization to NPs, the cyclic ones assure long lasting dispersions. While the thermally induced dehydration of linear PEOXA shells cause irreversible aggregation of the NPs, the collapse and subsequent rehydration of similarly grafted cyclic brushes allow the full recovery of individually dispersed NPs. Although linear ligands are densely grafted onto Fe3O4 cores, a small plasma protein such as bovine serum albumin (BSA) still physisorbs within their shells. In contrast, the impenetrable entropic shield provided by cyclic brushes efficiently prevents nonspecific interaction with proteins.

Next-Generation Polymer Shells for Inorganic Nanoparticles are Highly Compact, Ultra-Dense, and Long-Lasting Cyclic Brushes.

Cyclic poly-2-ethyl-2-oxazoline (PEOXA) ligands for superparamagnetic Fe3 O4 nanoparticles (NPs) generate ultra-dense and highly compact shells, providing enhanced colloidal stability and bio-inertness in physiological media. When linear brush shells fail in providing colloidal stabilization to NPs, the cyclic ones assure long lasting dispersions. While the thermally induced dehydration of linear PEOXA shells cause irreversible aggregation of the NPs, the collapse and subsequent rehydration of similarly grafted cyclic brushes allow the full recovery of individually dispersed NPs. Although linear ligands are densely grafted onto Fe3 O4 cores, a small plasma protein such as bovine serum albumin (BSA) still physisorbs within their shells. In contrast, the impenetrable entropic shield provided by cyclic brushes efficiently prevents nonspecific interaction with proteins.

Topological Polymer Chemistry Enters Surface Science: Linear versus Cyclic Polymer Brushes

AbstractThe cyclic polymer topology strongly alters the interfacial, physico‐chemical properties of polymer brushes, when compared to the linear counterparts. In this study, we especially concentrated on poly‐2‐ethyl‐2‐oxazoline (PEOXA) cyclic and linear grafts assembled on titanium oxide surfaces by the “grafting‐to” technique. The smaller hydrodynamic radius of ring PEOXAs favors the formation of denser brushes with respect to linear analogs. Denser and more compact cyclic brushes generate a steric barrier that surpasses the typical entropic shield by a linear brush. This phenomenon, translates into an improved resistance towards biological contamination from different protein mixtures. Moreover, the enhancement of steric stabilization coupled to the intrinsic absence of chain ends by cyclic brushes, produce surfaces displaying a super‐lubricating character when they are sheared against each other. All these topological effects pave the way for the application of cyclic brushes for surface functionalization, enabling the modulation of physico‐chemical properties that could be just marginally tuned by applying linear grafts.

Topological Polymer Chemistry Enters Surface Science: Linear versus Cyclic Polymer Brushes.

The cyclic polymer topology strongly alters the interfacial, physico-chemical properties of polymer brushes, when compared to the linear counterparts. In this study, we especially concentrated on poly-2-ethyl-2-oxazoline (PEOXA) cyclic and linear grafts assembled on titanium oxide surfaces by the "grafting-to" technique. The smaller hydrodynamic radius of ring PEOXAs favors the formation of denser brushes with respect to linear analogs. Denser and more compact cyclic brushes generate a steric barrier that surpasses the typical entropic shield by a linear brush. This phenomenon, translates into an improved resistance towards biological contamination from different protein mixtures. Moreover, the enhancement of steric stabilization coupled to the intrinsic absence of chain ends by cyclic brushes, produce surfaces displaying a super-lubricating character when they are sheared against each other. All these topological effects pave the way for the application of cyclic brushes for surface functionalization, enabling the modulation of physico-chemical properties that could be just marginally tuned by applying linear grafts.

Hydrate Inhibition with PEO (Poly 2-ethyl-2-oxazoline)

This study is aimed at investigating the effects of a poly 2-ethyl-2-oxazoline-type polymer on the prevention of methane hydrate formation. During the study, seven experiments with low concentrations of poly 2-ethyl-2-oxazoline (0 to 1 wt%) were run in a batch-type reactor. The analysis of the experimental study indicates that poly 2-ethyl-2-oxazoline can be considered as a potential kinetic inhibitor for hydrate formation.

Compatibilization of Protein Thermoplastics and Polybutylene Succinate Blends

AbstractReactive extrusion was used to prepare blends of Novatein thermoplastic protein (NTP) and poly(butylene succinate) (PBS) compatibilized with poly‐2‐ethyl‐2‐oxazoline (PEOX) and polymeric methylene diphenyl diisocyanate (pMDI). PEOX improved the dispersion of NTP in PBS and in conjunction with pMDI led to improved water resistance and a tensile strength exceeding that of NTP and PBS. The secant modulus, elongation as well as energy to break were also improved. The glass transition temperature (Tg) of compatibilized blends remained unchanged, however, the melting enthalpy and temperature decreased. This suggested that the crystalline structure of PBS has been disrupted by NTP as a result of compatibilization.

Mechanical Properties of Thermoplastic Protein From Bloodmeal and Polyester Blends

Blends of bloodmeal-based thermoplastic (NTP) and polybutylene succinate (PBS) were prepared to study the effect of compatibilization on mechanical properties. The Taguchi method was used for experimental design and the results were analysed in terms of signal-to-noise (S/N) ratios using analysis of variance (ANOVA). Between 5 and 10 wt.-% of either poly-2-ethyl-2-oxazoline (PEOX) and poly [(phenyl isocyanate)-co-formaldehyde] (pMDI) were used as compatibilizers in blends of 20–100% NTP. The tensile strength of the blends depended on the type of compatibilizer used while for elongation at break and modulus, NTP content had the largest influence. Compatibilizing efficiency was more pronounced at higher NTP content. The blend's morphology showed a smaller particle size for blends at optimal tensile properties while plastic deformation was observed for samples where elongation at break was optimal.