scholarly journals Molecularly Imprinted Chitosan-Based Thin Films with Selectivity for Nicotine Derivatives for Application as a Bio-Sensor and Filter

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3363
Author(s):  
Obinna Ofoegbu ◽  
David Chukwuebuka Ike ◽  
Gaber El-Saber Batiha ◽  
Hassan Fouad ◽  
Roongnapa S. Srichana ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Quartz Crystal ◽  
Time Interval ◽  
Film Sensor ◽  
Balance System ◽  
Chitosan Matrix ◽  
Nicotine Derivatives ◽  
Quartz Crystal Resonators ◽  
Single Matrix

This study reports the feasible use of chitosan as a thin film biosensor on the very sensitive quartz crystal micro balance system for detection of blends of multiple templates within a single matrix. The development of chitosan-based thin film materials with selectivity for nicotine derivatives is described. The molecular imprinting of a combination of nicotine derivatives in N-diacryloyl pipiradine-chitosan-methacrylic acid copolymer films on quartz crystal resonators was used to generate thin films with selectivity for nicotine and a range of nicotine analogues, particularly 3-phenylpyridine. The polymers were characterized by spectroscopic and microscopic evaluations; surface area, pore size, pore volume using Breuner-Emmet-Teller method. Temperature characteristics were also studied. The swelling and structure consistency of the Chitosan was achieved by grafting with methylmethacrylic acid and cross-linking with N-diacrylol pipiradine. A blend of 0.002 g (0.04 mmol) of Chitosan, 8.5 μL Methylmethacrylic Acid and 1.0 mg N-diacrylol pipradine (BAP) presented the best blend formulation. Detections were made within a time interval of 99 sec, and blend templates were detected at a concentration of 0.5 mM from the Quartz crystal microbalance resonator analysis. The successful crosslinking of the biopolymers ensured successful control of the swelling and agglomeration of the chitosan, giving it the utility potential for use as thin film sensor. This successful crosslinking also created successful dual multiple templating on the chitosan matrix, even for aerosolized templates. The products can be used in environments with temperature ranges between 60 °C and 250 °C.

Effect of Temperature on the Electrical and Gas Sensing Properties of Polyaniline and Multiwall Carbon Nanotube Doped Polyaniline Composite Thin Films

2011 ◽  
Vol 254 ◽  
pp. 167-170 ◽  
Author(s):  
Subodh Srivastava ◽  
Sumit Kumar ◽  
Vipin Kumar Jain ◽  
Y.K. Vijay
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
Composite Thin Film ◽  
Effect Of Temperature ◽  
Multiwall Carbon Nanotube ◽  
Film Sensor ◽  
Composite Thin Films ◽  
Pani Composite

In the present work we have reported the effect of temperature on the gas sensing properties of pure Polyaniline (PANI) and Multiwall carbon nanotube (MWNT) doped PANI composite thin film based chemiresistor type gas sensors for hydrogen gas sensing application. PANI and MWNT doped PANI composite were synthesized by in situ chemical oxidative polymerization of aniline using ammonium persulfate in an acidic medium. The thin sensing film of chemically synthesized PANI and MWNT doped PANI composite were deposited onto finger type Cu-interdigited electrodes using spin cast technique to prepared chemiresistor type gas sensor. The electrical properties of these composite thin films were characterized by I-V measurements as function of temperature. The I-V measurement revealed that conductivity of composite thin films increased as the temperature increased. The changes in resistance of the composite thin film sensor were utilized for detection of hydrogen gas. It was observed that at room temperature, MWNT doped PANI composite sensor shows higher response value and sensitivity with good repeatability in comparison to pure PANI thin film sensor. It was also observed that both PANI and MWNT doped PANI composite thin film based sensors showed unstable behavior as the temperature increased. The surface morphology of these composite thin films has also been characterized by scanning electron microscopy (SEM) measurement.

LTCC Substrates for High Performance Strain Gauges

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000175-000180
Author(s):  
Bjoern Brandt ◽  
Marion Gemeinert ◽  
Ralf Koppert ◽  
Jochen Bolte ◽  
Torsten Rabe
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Performance ◽  
Coefficient Of Thermal Expansion ◽  
Strain Gauges ◽  
Gauge Factor ◽  
Metal Foil ◽  
Accuracy Class ◽  
Film Sensor ◽  
Load Cells

Recent advances in the development of high gauge factor thin-films for strain gauges prompt the research on advanced substrate materials. A glass ceramic composite has been developed in consideration of a high coefficient of thermal expansion and a low modulus of elasticity for the application as support material for thin-film sensors. Constantan foil strain gauges were fabricated from this material by tape casting, pressure-assisted sintering and subsequent lamination of the metal foil on the planar ceramic substrates. The sensors were mounted on a strain gauge beam arrangement and load curves and creep behavior were evaluated. The accuracy of the assembled load cells correspond to accuracy class C6. That qualifies the load cells for the use in automatic packaging units and confirms the applicability of the LTCC substrates for fabrication of accurate strain gauges. To facilitate the deposition of thin film sensor structures onto the LTCC substrates, the pressure-assisted sintering technology has been refined. By the use of smooth setters instead of release tapes substrates with minimal surface roughness were fabricated. Metallic thin films deposited on these substrates exhibit low surface resistances comparable to thin films on commercial alumina thin-film substrates. The presented advances in material design and manufacturing technology are important to promote the development of high performance thin-film strain gauges.

Progress in monitoring thin film thickness with quartz crystal resonators

1976 ◽  
Vol 32 (1) ◽  
pp. 27-33 ◽  
Author(s):  
H.K. Pulker ◽  
E. Benes ◽  
D. Hammer ◽  
E. Söllner
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Quartz Crystal ◽  
Thin Film Thickness ◽  
Quartz Crystal Resonators

Feature Difference of Interaction between Various Organic Solvent Vapors and Metal Phthalocyanines Coated on Quartz Crystal

2008 ◽  
Vol 55-57 ◽  
pp. 305-308
Author(s):  
Tippavan Hongkachern ◽  
W. Suwannet ◽  
Rawat Jaisutti ◽  
S. Pratontep ◽  
Tanakorn Osotchan
Keyword(s):  
Thin Film ◽  
Organic Solvent ◽  
Resonance Frequency ◽  
Frequency Shift ◽  
Quartz Crystal ◽  
Copper Phthalocyanine ◽  
Principal Component ◽  
Zinc Phthalocyanine ◽  
Quartz Crystal Resonators ◽  
Solvent Vapors

Interaction between organic solvent vapors, zinc phthalocyanine (ZnPc) and copper phthalocyanine (CuPc) coated on quartz crystal resonators were investigated for various types of organic solvent vapors including acetone, propanol, ethanol, tetrahydrofuran, methanol, nail lacquer remover, 100 Pipers and Masterblend whiskies. The major different features of the resonance frequency shift as a function of time were extracted in order to employ in gas sensor. The sensor consists of ZnPc or CuPc thin film with the thickness of ~300 nm coated on quartz crystal with resonance frequency of 2 MHz. It used as a transducer by convert the surface adsorption into the frequency shift. When the odor interacts with ZnPc or CuPc layer, the quartz frequency normally decreases from the fundamental frequency due to the additional mass on quartz surface. The different types of organic solvent have different sensitivity to the thin film and these changing lead to the different frequency shift characteristics. The frequency shift were collected and the selected data points at the time of 5, 10, 15, 20, 70, 75, and 80 minutes after dropping alcohol were used to extract the feature by using the principal component analysis (PCA) in order to classify the type of alcohol. The PCA can be used to identify the major characteristic difference of various organic solvent interactions. The main features can be identified by the amount of the frequency shift and the decay characteristics.

Viscoelastic properties of thin films studied with quartz crystal resonators

1997 ◽  
Vol 107 ◽  
pp. 91-104 ◽  
Author(s):  
Oliver Wolff ◽  
Eberhard Seydel ◽  
Diethelm Johannsmann
Keyword(s):  
Thin Films ◽  
Viscoelastic Properties ◽  
Quartz Crystal ◽  
Quartz Crystal Resonators

scholarly journals Recent advances in Performance and effect of Zr doping with ZnO thin film sensor in Ammonia Vapour Sensing

2021 ◽  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Gas Sensing ◽  
Wide Band ◽  
Fast Response ◽  
Sem Analysis ◽  
Zno Thin Film ◽  
Film Sensor ◽  
Doped Zno ◽  
Silar Technique

<p>Pure and Zr doped ZnO thin films were prepared using SILAR technique. The influence of Zr doping on structural, morphological, optical and gas sensing properties of ZnO has been reported. X-ray diffraction study confirmed the formation of wurtzite structure of ZnO thin film (JCPDS 36-1451) fabricated by SILAR technique and the caluculated crystallites size of pure and doped ZnO were 39 and 36 nm respectively . SEM analysis of thin films has shown a completely different surface morphology. EDAX spetrum cnfirmed the presence of different compositional element in the fabriated thin films. Zr (3 wt%) doped ZnO thin film exhibited the best properties with a good transmittance and it has wide band gap of 3.26 eV. Photoluminescence emissions indicated increase in concentration of oxygen vacancies with introduction of dopant. NH3 vapour sensors were fabricated out of fabricated samples and it was observed that doped samples have significantly high sensing response, good selectivity, fast response and recovery time to ammonia vapoutr at room temperature.</p>

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