Green Preparation of an Environment-Responsive Polymer

2013 ◽  
Vol 750-752 ◽  
pp. 1235-1238
Author(s):  
Qian Hou ◽  
Zhao Zhang ◽  
Ting Ting Yang ◽  
Yan Zhang
Keyword(s):  
Preparation Method ◽  
Reaction System ◽  
Functional Materials ◽  
Transformation Property ◽  
Solution Temperature ◽  
Smart Polymers ◽  
Critical Solution Temperature ◽  
Isopropyl Acrylamide ◽  
Responsive Polymer ◽  
Chemical Constitution

Smart polymers are very important in many fields, such as biochemistry, fine chemicals and functional materials, etc. In this paper, poly (N-isopropyl acrylamide) (PNIPAm) was prepared by ultrasonics sonochemistry. In the reaction system, the monomer is N-isopropyl acrylamide (NIPAm), the crosslinker is N,N'-methylenebisacrylamide (BIS) and the solvent is tetrahydrofuran (THF). FTIR and UV-Vis were used to investigate the chemical constitution and phase transformation property of PNIPAm. The results show that it is successful to obtain PNIPAm. It has thermosensitivity. And its lower critical solution temperature is found to be 34°C. Therefore, a green preparation method for environment-responsive polymer is presented.

scholarly journals Thermally responsive polymeric hydrogel brushes: synthesis, physical properties and use for the culture of chondrocytes

2006 ◽  
Vol 4 (12) ◽  
pp. 117-126 ◽  
Author(s):  
John Collett ◽  
Aileen Crawford ◽  
Paul V Hatton ◽  
Mark Geoghegan ◽  
Stephen Rimmer
Keyword(s):  
Crosslink Density ◽  
Cell Attachment ◽  
Viable Cell ◽  
Contact Angles ◽  
Polymer Chains ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Thermally Responsive ◽  
Isopropyl Acrylamide ◽  
Responsive Polymer

Hydrogel brushes are materials composed of a water-swollen network, which contains polymer chains that are grafted with another polymer. Using a thermally responsive polymer, poly( N -isopropyl acrylamide) (polyNIPAM), as the graft component we are able to maintain the critical solution temperature ( T crit ), independent of the overall composition of the material, at approximately 32°C. The change in swelling at T crit is a function of the amount of polyNIPAM in the system. However, there is a much smaller change in the surface contact angles at T crit . PolyNIPAM-based materials have generated considerable interest, as ‘smart’ substrates for the culture of cells and here, we show the utility of hydrogel brushes in cell culture. Chondrocytes attached to the hydrogel brushes and yielded viable cell cultures. Moreover, the chondrocytes could be released from the hydrogel brushes without the use of proteases by reducing the temperature of the cultures to below T crit to induce a change in the conformation of the polyNIPAM chain at T crit . The importance of the crosslink hydrogel component is illustrated by significant changes in cell attachment/cell viability as the crosslink density is changed.

Superabsorbent Nanohydrogels of Poly (N-Isopropyl Acrylamide-Co-Itaconic Acid) Grafted on Starch — Synthesis and Swelling Study

Nano LIFE ◽  
2016 ◽  
Vol 06 (02) ◽  
pp. 1650005 ◽  
Author(s):  
Karim Pourjamal ◽  
Marziyeh Fathi ◽  
Ali Akbar Entezami ◽  
Mohammad Hasanzadeh ◽  
Nasrin Shadjou
Keyword(s):  
Itaconic Acid ◽  
Starch Synthesis ◽  
Ammonium Persulfate ◽  
Solution Temperature ◽  
Scanning Calorimetry ◽  
Critical Solution Temperature ◽  
Dsc Studies ◽  
Isopropyl Acrylamide ◽  
Effects Of Ph

Biopolymer-based superabsorbent nanohydrogel consisting of N-isopropylacrylamide and itaconic acid (IA) was grafted on to starch backbone in an aqueous solution in the absence of the cross-linker agents. The copolymerization reaction occurred in the presence of ammonium persulfate (APS) as an initiator. The effect of N-isopropylacrylamide-to-IA ratio and different concentrations of initiator were investigated. The nanohydrogel composition was characterized by Fourier transform infrared spectroscopy (FTIR). The thermal stability was analyzed by Thermogravimetric analysis (TGA). Differential scanning calorimetry (DSC) studies were employed for determination of lower critical solution temperature in hydrogels. Dynamic light scattering analysis showed a narrow size distribution around 70–200[Formula: see text]nm for the synthesized nanohydrogels. The effects of pH on swelling behavior of the hydrogel were investigated. The obtained nanohydrogels, due to their pH and thermo dual sensitive properties, have the potential to be used in the drug delivery systems.

scholarly journals Upper or lower critical solution temperature, or both? Studies on cationic copolymers of N-isopropylacrylamide

2015 ◽  
Vol 6 (16) ◽  
pp. 3074-3082 ◽  
Author(s):  
Erno Karjalainen ◽  
Vladimir Aseyev ◽  
Heikki Tenhu
Keyword(s):  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Trimethylammonium Chloride ◽  
Solution Properties ◽  
Critical Solution Temperature ◽  
Isopropyl Acrylamide ◽  
Cationic Copolymers

The solution properties of statistical copolymers of N-isopropyl acrylamide (NIPAm) and cationic (3-acrylamidopropyl) trimethylammonium chloride (AMPTMA) have been studied.

Synthesis and Characterization of Core-Shell Thermo-Responsive Microgels with Linear Transition Behavior

2015 ◽  
Vol 671 ◽  
pp. 261-266
Author(s):  
Shu Lin Guan ◽  
Na Fan ◽  
Qi Zhong ◽  
Ji Ping Wang
Keyword(s):  
Particle Size ◽  
Solution Temperature ◽  
Core Shell ◽  
Critical Solution Temperature ◽  
The Core ◽  
Transition Behavior ◽  
Isopropyl Acrylamide ◽  
Poly Ethylene ◽  
Glycol Methyl Ether

Thermo-responsive microgels with core-shell structure were prepared by free radical emulsion polymerization. The core of microgels was consisted of poly (N-isopropyl acrylamide) (PNIPAM), while the shell was consisted of poly (ethylene glycol) methyl ether methacrylate (POEGMA300). In order to compare the transition behavior of the core-shell microgels with the microgels consisted of one thermo-responsive microgel, PNIPAM and POEGMA300 microgels were prepared. PNIPAM exhibits a lower critical solution temperature (LCST) of 32 °C, and the LCST of POEGMA300 is approximately 63 °C. The thermo-responsive microgel behavior was measured by dynamic light scattering (DLS). It is observed that both of PNIPAM and POEGMA300 microgels show a thermo-responsive ability. The particle size significantly drops when the temperature passes LCST. Moreover the particle size of the thermo-responsive microgels with core (PNIPAM)-shell (POEGMA300) structure shows a linear transition behavior when the temperature is between 50 °C and 70 °C.

scholarly journals Smart Hydrogels: Preparation, Characterization, and Determination of Transition Points of Crosslinked N-Isopropyl Acrylamide/Acrylamide/Carboxylic Acids Polymers

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 113
Author(s):  
Yasemin Işıkver ◽  
Dursun Saraydın
Keyword(s):  
The Body ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Isopropyl Acrylamide ◽  
Different Temperatures ◽  
Swelling Characteristics ◽  
Swelling Studies ◽  
Transition Points ◽  
Tga And Dsc

Smart hydrogels (SH) were prepared by thermal free radical polymerization of N-isopropyl acrylamide (NIPAAm), acrylamide (AAm) with acrylic acid (A) or maleic acid (M), and N, N′-methylene bisacrylamide. Spectroscopic and thermal characterizations of SHs were performed using FTIR, TGA, and DSC. To determine the effects of SHs on swelling characteristics, swelling studies were performed in different solvents, solutions, temperatures, pHs, and ionic strengths. In addition, cycle equilibrium swelling studies were carried out at different temperatures and pHs. The temperature and pH transition points of SHs are calculated using a sigmoidal equation. The pH transition points were calculated as 5.2 and 4.2 for SH-M and SH-A, respectively. The NIPAAm/AAm hydrogel exhibits a critical solution temperature (LCST) of 28.35 °C, while the SH-A and SH-M hydrogels exhibit the LCST of 34.215 °C and 28.798 °C, respectively, and the LCST of SH-A is close to the body. temperature. Commercial (CHSA) and blood human serum albumin (BHSA) were used to find the adsorption properties of biopolymers on SHs. SH-M was the most efficient SH, adsorbing 49% of CHSA while absorbing 16% of BHSA. In conclusion, the sigmoidal equation or Gaussian approach can be a useful tool for chemists, chemical engineers, polymer and plastics scientists to find the transition points of smart hydrogels.

Polydopamine Nanoparticle for Poly(N-Isopropylacrylamide)-Based Nanocomposite Hydrogel with Good Free-Radical-Scavenging Property

2016 ◽  
Vol 848 ◽  
pp. 94-98 ◽  
Author(s):  
Shu Qiang Xiong ◽  
Yan Wang ◽  
Jing Zhu ◽  
Zu Ming Hu ◽  
Jun Rong Yu
Keyword(s):  
Free Radical ◽  
Radical Scavenging ◽  
Antioxidant Property ◽  
Solution Temperature ◽  
Scavenge Activity ◽  
Initial Reaction ◽  
Critical Solution Temperature ◽  
Nanocomposite Hydrogels ◽  
Isopropyl Acrylamide

Nanocomposite hydrogels (NC gels) consisting of poly (N-Isopropyl acrylamide) (pNIPAM)/polydopamine nanoparticles (PDAPs) were prepared by in-situ-free-radical polymerization of N-isopropyl acrylamide in the presence of modified PDAP in aqueous solution. The composition of the NC gels could be controlled directly by altering the composition of the initial reaction mixture. The lower critical solution temperature (LCST) of the NC gels were studied by DSC, and the LCST of both of pure pNIPAM hydrogel and NC gels was at 34°C. Besides, the NC gels showed superior antioxidant property, and the ability to scavenge activity of NC gel was up to 70% with the addition of 6 wt% modified PDAP into pNIPAM.

scholarly journals Upper critical solution temperature thermo-responsive polymer brushes and a mechanism for controlled cell attachment

2017 ◽  
Vol 5 (25) ◽  
pp. 4926-4933 ◽  
Author(s):  
Xuan Xue ◽  
Lalitha Thiagarajan ◽  
Shwana Braim ◽  
Brian R Saunders ◽  
Kevin M Shakesheff ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Cell Attachment ◽  
Control Cell ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Upper Critical Solution Temperature ◽  
Responsive Polymer

We report the synthesis of thermo-responsive polymer brushes with Upper Critical Solution Temperature (UCST)-type behaviour on glass to provide a new means to control cell attachment.

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