scholarly journals Chiral recognition of macromolecules with cyclodextrins: pH- and thermosensitive copolymers from N-isopropylacrylamide and N-acryloyl-D/L-phenylalanine and their inclusion complexes with cyclodextrins

2011 ◽  
Vol 7 ◽  
pp. 204-209 ◽  
Author(s):  
Sabrina Gingter ◽  
Ella Bezdushna ◽  
Helmut Ritter
Keyword(s):  
Ph Value ◽  
High Sensitivity ◽  
2D Nmr ◽  
Water Soluble ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
2D Nmr Spectroscopy ◽  
Enantioselective Recognition ◽  
Stimuli Responsive Polymers ◽  
Thermosensitive Copolymers

In the present work we report the enantioselective recognition of water soluble stimuli-responsive polymers bearing phenylalanine moieties via host-guest interaction with β-cyclodextrin and randomly-methylated-β-cyclodextrin (RAMEB-CD). We synthesised N-acryloyl-D/L-phenylalanine monomers (2 D , 2 L ) which were then copolymerised under free radical conditions with N-isopropylacrylamide (NIPAAm). The resulting copolymers 3 D and 3 L exhibit a lower critical solution temperature (LCST) of 25 °C. As a further benefit, the presence of a free carboxylic group in the copolymer system gives a high sensitivity to the pH value in respect to the LCST value. The enantioselective recognition of the side groups of copolymers 3 D and 3 L and their solubility behaviour were investigated by dynamic light scattering and 2D NMR spectroscopy, respectively.

Smart Polymers and their Applications: A Review

2017 ◽  
Vol 8 (03) ◽  
Author(s):  
Gore S. A. ◽  
Gholve S. B. ◽  
Savalsure S. M. ◽  
Ghodake K. B. ◽  
Bhusnure O. G. ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Water Soluble ◽  
Solution Temperature ◽  
Smart Polymers ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Water Soluble Polymers ◽  
Commercial Applications ◽  
Stimuli Sensitive ◽  
External Stimuli

Smart polymers are materials that respond to small external stimuli. These are also referred as stimuli responsive materials or intelligent materials. Smart polymers that can exhibit stimuli-sensitive properties are becoming important in many commercial applications. These polymers can change shape, strength and pore size based on external factors such as temperature, pH and stress. The stimuli include salt, UV irradiation, temperature, pH, magnetic or electric field, ionic factors etc. Smart polymers are very promising applicants in drug delivery, tissue engineering, cell culture, gene carriers, textile engineering, oil recovery, radioactive wastage and protein purification. The study is focused on the entire features of smart polymers and their most recent and relevant applications. Water soluble polymers with tunable lower critical solution temperature (LCST) are of increasing interest for biological applications such as cell patterning, smart drug release, DNA sequencing etc.

scholarly journals Thermo- and Photoresponsive Behaviors of Dual-Stimuli-Responsive Organogels Consisting of Homopolymers of Coumarin-Containing Methacrylate

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 329
Author(s):  
Seidai Okada ◽  
Eriko Sato
Keyword(s):  
Functional Group ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Critical Solution Temperature ◽  
Equilibrium Degree ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Dual Functional ◽  
Wide Range ◽  
Increasing Temperature

Coumarin-containing vinyl homopolymers, such as poly(7-methacryloyloxycoumarin) (P1a) and poly(7-(2′-methacryloyloxyethoxy)coumarin) (P1b), show a lower critical solution temperature (LCST) in chloroform, which can be controlled by the [2 + 2] photochemical cycloaddition of the coumarin moiety, and they are recognized as monofunctional dual-stimuli-responsive polymers. A single functional group of monofunctional dual-stimuli-responsive polymers responds to dual stimuli and can be introduced more uniformly and densely than those of dual-functional dual-stimuli-responsive polymers. In this study, considering a wide range of applications, organogels consisting of P1a and P1b, i.e., P1a-gel and P1b-gel, respectively, were synthesized, and their thermo- and photoresponsive behaviors in chloroform were investigated in detail. P1a-gel and P1b-gel in a swollen state (transparent) exhibited phase separation (turbid) through a temperature jump and reached a shrunken state (transparent), i.e., an equilibrium state, over time. Moreover, the equilibrium degree of swelling decreased non-linearly with increasing temperature. Furthermore, different thermoresponsive sites were photopatterned on the organogel through the photodimerization of the coumarin unit. The organogels consisting of homopolymers of coumarin-containing methacrylate exhibited unique thermo- and photoresponsivities and behaved as monofunctional dual-stimuli-responsive organogels.

Systematic evaluation of pH and thermoresponsive poly(n-isopropylacrylamide-chitosan-fluorescein) microgel

e-Polymers ◽  
2017 ◽  
Vol 17 (5) ◽  
pp. 399-408 ◽  
Author(s):  
Pedro Hernández ◽  
Armando Lucero-Acuña ◽  
Cindy Alejandra Gutiérrez-Valenzuela ◽  
Ramón Moreno ◽  
Reynaldo Esquivel
Keyword(s):  
Biomedical Application ◽  
Systematic Evaluation ◽  
Molar Ratio ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Scanning Calorimetry ◽  
Molar Ratios ◽  
Stimuli Responsive Polymers ◽  
Wide Range ◽  
Low Molecular Weight Chitosan

AbstractThe interesting properties of stimuli-responsive polymers lead to a wide range of possibilities in design and engineering of functional material for the biomedical application. A systematic approach focused on the evaluation of the physical properties of multiresponse (pH and temperature) PNIPAM was reported in this work. The effect of three different molar ratios of poly(n-isopropylacrylamide): chitosan (1:49, 1:99 and 1:198) were evaluated and labeled correspondingly as PC1F, PC2F, and PC3F. An increase in the lower critical solution temperature (LCST) of sample PC1F (34°C) was observed by differential scanning calorimetry (DSC). The presence of low molecular weight chitosan (LMWC) full-interpenetrating polymer (Full-IPN) segments in poly(n-isopropylacrylamide) was confirmed by Fourier-transform infrared spectroscopy (FT-IR). The hydrogel’s water capture was analyzed by two models of swelling, the power law model and a model that considers the relaxation of polymeric chains of the hydrogel, finding good correlations with experimental data in both cases. Sample PC3F resulted with higher swellability, increasing the weight of the hydrogel around seven times. Hydrogel pH-sensibility was confirmed placing the samples at different pH environments, with an apparent increase in swellability for acidic conditions, confirming the highest swellability for sample PC3F, due to hydrogen bonds boosted by chitosan high molar ratio. Based on these results, the hydrogel obtained has potential as a thermo-pH triggered hydrogel in drug delivery applications.

Conformation of a water-soluble derivative of taxol in water by 2D-NMR spectroscopy

1994 ◽  
Vol 1 (2) ◽  
pp. 107-112 ◽  
Author(s):  
Luigi Gomez Paloma ◽  
R.Kiplin Guy ◽  
W. Wrasidlo ◽  
K.C. Nicolaou
Keyword(s):  
Nmr Spectroscopy ◽  
2D Nmr ◽  
Water Soluble ◽  
2D Nmr Spectroscopy

scholarly journals How to manipulate the upper critical solution temperature (UCST)?

2017 ◽  
Vol 8 (1) ◽  
pp. 220-232 ◽  
Author(s):  
Jukka Niskanen ◽  
Heikki Tenhu
Keyword(s):  
Aqueous Solutions ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Critical Solution Temperature ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Ph Influence ◽  
Counter Ions ◽  
Upper Critical Solution Temperature

In this mini-review, we discuss multi-stimuli-responsive polymers, which exhibit upper critical solution temperature (UCST) behavior mainly in aqueous solutions, and focus on examples where counter ions, electricity, light, or pH influence the thermoresponsiveness of these polymers.

scholarly journals Adamantane Functionalized Poly(2-oxazoline)s with Broadly Tunable LCST-Behavior by Molecular Recognition

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 374
Author(s):  
Joachim F. R. Van Guyse ◽  
Debaditya Bera ◽  
Richard Hoogenboom
Keyword(s):  
Phase Transition ◽  
Molecular Recognition ◽  
High Specificity ◽  
Polymer Chains ◽  
Solution Temperature ◽  
Side Chains ◽  
Stimuli Responsive ◽  
Thermal Transitions ◽  
Stimuli Responsive Polymers ◽  
Interactive Behavior

Smart or adaptive materials often utilize stimuli-responsive polymers, which undergo a phase transition in response to a given stimulus. So far, various stimuli have been used to enable the modulation of drug release profiles, cell-interactive behavior, and optical and mechanical properties. In this respect, molecular recognition is a powerful tool to fine-tune the stimuli-responsive behavior due to its high specificity. Within this contribution, a poly(2-oxazoline) copolymer bearing adamantane side chains was synthesized via triazabicyclodecene-catalyzed amidation of the ester side chains of a poly(2-ethyl-2-oxazoline-stat-2-methoxycarbonylpropyl-2-oxazoline) statistical copolymer. Subsequent complexation of the pendant adamantane groups with sub-stoichiometric amounts (0–1 equivalents) of hydroxypropyl β-cyclodextrin or β-cyclodextrin enabled accurate tuning of its lower critical solution temperature (LCST) over an exceptionally wide temperature range, spanning from 30 °C to 56 °C. Furthermore, the sharp thermal transitions display minimal hysteresis, suggesting a reversible phase transition of the complexed polymer chains (i.e., the β-cyclodextrin host collapses together with the polymers) and a minimal influence by the temperature on the supramolecular association. Analysis of the association constant of the polymer with hydroxypropyl β-cyclodextrin via 1H NMR spectroscopy suggests that the selection of the macrocyclic host and rational polymer design can have a profound influence on the observed thermal transitions.

scholarly journals Synthesis and Aggregation Behavior of Temperature- and pH-Responsive Glycopolymers as Sugar-Displaying Conjugates

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 956 ◽  
Author(s):  
Sotaro Tsuji ◽  
Tomohiro Aoki ◽  
Shunsuke Ushio ◽  
Tomonari Tanaka
Keyword(s):  
Aqueous Media ◽  
Temperature Limit ◽  
Radical Copolymerization ◽  
Advanced Materials ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Ph Responsive ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Hydrolysis Of

Stimuli-responsive polymers have attracted significant interest in the fields of advanced materials and biomaterials. Herein, temperature- and pH-responsive glycopolymers, which are composed of N-isopropylacrylamide, methacrylic acid, and an acrylamide derivative bearing a lactose moiety, were synthesized via radical copolymerization. The series of resulting glycopolymers had different degrees of substitution of the lactose moieties, were responsive to temperatures between 26.6 °C and 47.6 °C, and formed aggregates above the lower critical solution temperature limit in mild acidic aqueous media (pH 4–6). The temperature-responsive behavior was dependent on the prevailing pH conditions, as no aggregation was observed in neutral and basic aqueous media (pH > 7). The aggregates had saccharide moieties on the surface in aqueous media. The number of saccharide moieties on the surface depended on the saccharide-containing unit ratio in the glycopolymer. The ratio was determined via enzymatic hydrolysis of the lactose moieties using β-galactosidase and the subsequent detection of the released galactose.

Redox-controlled upper critical solution temperature behaviour of a nitroxide containing polymer in alcohol–water mixtures

2016 ◽  
Vol 7 (5) ◽  
pp. 1088-1095 ◽  
Author(s):  
Olivier Bertrand ◽  
Alexandru Vlad ◽  
Richard Hoogenboom ◽  
Jean-François Gohy
Keyword(s):  
Solution Temperature ◽  
Stimuli Responsive ◽  
Temperature Behaviour ◽  
Critical Solution Temperature ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Alcohol Water ◽  
Upper Critical Solution Temperature

Research on stimuli responsive polymers builds momentum as nature-inspired applications using man-made materials are increasingly sought.

Amino-functional polyethers: versatile, stimuli-responsive polymers

2020 ◽  
Vol 11 (24) ◽  
pp. 3940-3950 ◽  
Author(s):  
Patrick Verkoyen ◽  
Holger Frey
Keyword(s):  
Ring Opening ◽  
Review Article ◽  
Stimuli Responsive ◽  
New Class ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers

Amino-functional polyethers have emerged as a new class of “smart”, i.e. pH- and thermoresponsive materials. This review article summarizes the synthesis and applications of these materials, obtained from ring-opening of suitable epoxide monomers.

Sign in / Sign up

Export Citation Format

Share Document