Ti₄O₇/PPy Composite pH Sensing Foam

90-Day Stable High Sensitivity

Tight binding of negatively charged Ti₄O₇-pTS particles with PPy chains suppresses dopant loss and polymer degradation, greatly enhancing long-term stability for biomedical pH sensing.

Yue, Cao · Dan, Wang · Qi, Kai · Qiu, Yubing · Guo, Xingpeng

Polymer Degradation and Stability 2025

Specifications

pH sensitivity after 90-day immersion

{'zh': '58', 'en': '58'} mV/pH

Stable sensitivity during days 30–60

{'zh': '63–64', 'en': '63–64'} mV/pH

Maximum sensitivity during activation

{'zh': '74', 'en': '74'} mV/pH

Advantages

Greatly enhanced stability

Tight binding of Ti₄O₇-pTS particles with PPy chains inhibits pTS⁻ loss and PPy degradation, keeping sensitivity at 58 mV/pH after 90 days.

Higher sensitivity

Composite sensitivity increases to 74 mV/pH during activation, stabilizes at 63–64 mV/pH during days 30–60, exceeding that of PPy/ACF.

Applications

• Biomedical pH Monitoring：Long-term stable pH measurement in biological fluids without frequent recalibration or electrode replacement
• Wearable Health Sensing：Integrate into wearable devices for continuous pH monitoring of sweat and other body fluids
• Implantable Diagnostic Devices：Use in implantable sensors for long-term stable in vivo pH monitoring