scholarly journals Synthesis and Characterization of N-Isopropylacrylamide Microspheres as pH Sensors

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6493
Author(s):  
Barry K. Lavine ◽  
Necati Kaval ◽  
Leah Oxenford ◽  
Mariya Kim ◽  
Kaushalya Sharma Dahal ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Ph Sensitive ◽  
Polymer Microspheres ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Polymer Particles ◽  
Buffer Solution ◽  
Sensitive Material ◽  
Polymer Swelling ◽  
Pva Solutions

Swellable polymer microspheres that respond to pH were prepared by free radical dispersion polymerization using N-isopropylacrylamide (NIPA), N,N′-methylenebisacrylamide (MBA), 2,2-dimethoxy-2-phenylacetylphenone, N-tert-butylacrylamide (NTBA), and a pH-sensitive functional comonomer (acrylic acid, methacrylic acid, ethacrylic acid, or propacrylic acid). The diameter of the microspheres was between 0.5 and 1.0 μm. These microspheres were cast into hydrogel membranes prepared by mixing the pH-sensitive swellable polymer particles with aqueous polyvinyl alcohol (PVA) solutions followed by crosslinking with glutaric dialdehyde for use as pH sensors. Large changes in the turbidity of the PVA membrane were observed as the pH of the buffer solution in contact with the membrane was varied. These changes were monitored by UV–visible absorbance spectroscopy. Polymer swelling of many NIPA copolymers was reversible and independent of the ionic strength of the buffer solution in contact with the membrane. Both the degree of swelling and the apparent pKa of the polymer microspheres increased with temperature. Furthermore, the apparent pKa of the polymer particles could be tuned to respond sharply to pH in a broad range (pH 4.0–7.0) by varying the amount of crosslinker (MBA) and transition temperature modifier (NTBA), and the amount, pKa, and hydrophobicity of the pH-sensitive functional comonomer (alkyl acrylic acid) used in the formulation. Potential applications of these polymer particles include fiber optic pH sensing where the pH-sensitive material can be immobilized on the distol end of an optical fiber.

scholarly journals Investigations of Printed Flexible pH Sensing Materials Based on Graphene Platelets and Submicron RuO2Powders

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Daniel Janczak ◽  
Andrzej Peplowski ◽  
Grzegorz Wroblewski ◽  
Lukasz Gorski ◽  
Elzbieta Zwierkowska ◽  
...  
Keyword(s):  
Ruthenium Oxide ◽  
Ph Sensitive ◽  
Ruthenium Dioxide ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Sensitive Layer ◽  
Uv Curable ◽  
Before And After ◽  
Oxide Composites ◽  
Fabrication Costs

The paper describes the investigations of pH-sensitive materials for screen printed flexible pH sensors. The sensors were fully printed and consisted of three layers, conductive made of low temperature-curable silver paste, insulating made of UV-curable dielectric paste, and pH-sensitive made of developed graphene/ruthenium oxide pastes. Graphene and ruthenium oxide composites were prepared with different proportions of graphene nanoplatelets paste and submicron ruthenium dioxide. To perform functional measurements, particular testing sensors were fabricated on flexible polyester foil. Afterwards electrochemical potential measurements of fabricated devices were carried out. Sensors were also exposed to cyclic bending and the change of pH sensitivity before and after bending was described. Eventually, percolation threshold concerning the amount of ruthenium oxide in the pH-sensitive layer was designated and UV influence on the sensitivity was observed that together allow for optimization of sensors’ fabrication costs.

scholarly journals Titanium Nitride Thin Film Based Low-Redox-Interference Potentiometric pH Sensing Electrodes

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 42
Author(s):  
Shimrith Paul Shylendra ◽  
Wade Lonsdale ◽  
Magdalena Wajrak ◽  
Mohammad Nur-E-Alam ◽  
Kamal Alameh
Keyword(s):  
Thin Film ◽  
Titanium Nitride ◽  
Orange Juice ◽  
Ph Sensor ◽  
Reference Electrode ◽  
Cost Effective ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Potential Shift ◽  
Double Junction

In this work, a solid-state potentiometric pH sensor is designed by incorporating a thin film of Radio Frequency Magnetron Sputtered (RFMS) Titanium Nitride (TiN) working electrode and a commercial Ag|AgCl|KCl double junction reference electrode. The sensor shows a linear pH slope of −59.1 mV/pH, R2 = 0.9997, a hysteresis as low as 1.2 mV, and drift below 3.9 mV/h. In addition, the redox interference performance of TiN electrodes is compared with that of Iridium Oxide (IrO2) counterparts. Experimental results show −32 mV potential shift (E0 value) in 1 mM ascorbic acid (reducing agent) for TiN electrodes, and this is significantly lower than the −114 mV potential shift of IrO2 electrodes with sub-Nernstian sensitivity. These results are most encouraging and pave the way towards the development of miniaturized, cost-effective, and robust pH sensors for difficult matrices, such as wine and fresh orange juice.

Development of a facile one-pot synthesis method for an ingestible pH sensitive actuator

MRS Advances ◽  
2019 ◽  
Vol 5 (17) ◽  
pp. 881-889
Author(s):  
Alex Keller ◽  
Holly Warren ◽  
Marc in het Panhuis
Keyword(s):  
Acrylic Acid ◽  
Calcium Hydroxide ◽  
Sodium Citrate ◽  
Synthesis Method ◽  
Gastric Fluid ◽  
Ph Sensitive ◽  
One Pot ◽  
Acidic Environments ◽  
Printed Materials ◽  
Poly Acrylic Acid

ABSTRACTEdible devices are an emergent technology and in this paper the simplicity and efficacy that poly(acrylic acid)/calcium hydroxide possess in creating a pH sensitive ingestible actuator which responds to acidic environments such as gastric fluid is demonstrated. It was found that poly(acrylic acid)/calcium hydroxide hydrogels exhibit reversible actuation upon submerging in 0.1 M sodium citrate for 2 hours. Our results show that these hydrogels can restore their compressive stress to 0.19 ± 0.06 MPa, swelling ratio to 26 ± 2 and volume to 56% ± 3% of its original volume. This work offers new possibilities for developments in a variety of fields such as drug delivery, 4D printed materials, soft robotics and edible devices.

Preparation and characterization of a novel pH-sensitive Salecan-g-poly(acrylic acid) hydrogel for controlled release of doxorubicin

2015 ◽  
Vol 3 (13) ◽  
pp. 2685-2697 ◽  
Author(s):  
Xinyu Hu ◽  
Wei Wei ◽  
Xiaoliang Qi ◽  
Hao Yu ◽  
Liandong Feng ◽  
...  
Keyword(s):  
Controlled Release ◽  
Acrylic Acid ◽  
Ph Sensitive ◽  
Swelling Behaviour ◽  
Poly Acrylic Acid

The pH-sensitive swelling behaviour and DOX release of Salecan-g-PAA hydrogels are discussed.

Sign in / Sign up

Export Citation Format

Share Document