We showed that the addition of suberin fatty acids (SFAs) even at small concentrations significantly improves the water vapor barrier properties of hydroxypropyl methylcellulose (HPMC) films. SFAs were isolated from the outer birch bark using extractive hydrolysis. The effects of SFAs on the film formation of aqueous HPMC were investigated with free films plasticized with polyethylene glycol (PEG 400). Special attention was paid on the physical solid-state, moisture barrier and mechanical stress-strain properties of films intended for tablet film coatings. Topography and surface morphology, glass transition temperature (Tg), tensile strength, Young's modulus, and water vapor permeation (WVP) of films were studied. The addition of SFAs lowered the Tg of films suggesting partial enhancement in film plasticization. The WVP of films decreased with increasing SFAs concentration up to 15% (calculated as a % w/w from a polymer weight). The WVP value for a non-suberized reference film and suberized film plasticized with PEG 400 was 2.13×10(-6) and 0.69[×10(-6) g/(mm(2)×h)×mm/Pa], respectively. The addition of SFAs impaired the mechanical stress-strain properties of HPMC films by reducing the deformation capacity of film. In conclusion, the film properties and performance of aqueous HPMC can be modified by including SFAs in the films.
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http://dx.doi.org/10.1016/j.ijpharm.2015.04.066 | DOI Listing |
Adv Mater
December 2024
Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK.
High contact resistance remains the primary obstacle that hinders further advancements of organic semiconductors (OSCs) in electronic circuits. While significant effort has been directed toward lowering the energy barrier at OSC/metal contact interfaces, approaches toward reducing another major contributor to overall contact resistance - the bulk resistance - have been limited to minimizing the thickness of OSC films. However, the out-of-plane conductivity of OSCs, a critical aspect of bulk resistance, has largely remained unaddressed.
View Article and Find Full Text PDFMicrosyst Nanoeng
December 2024
Department of Mechanical Engineering, University of California, Berkeley, CA, 94720, USA.
This work presents air-coupled piezoelectric micromachined ultrasonic transducers (pMUTs) with high sound pressure level (SPL) under low-driving voltages by utilizing sputtered potassium sodium niobate KNaNbO (KNN) films. A prototype single KNN pMUT has been tested to show a resonant frequency at 106.3 kHz under 4 V with outstanding characteristics: (1) a large vibration amplitude of 3.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
National Engineering Lab of Special Display Technology, Special Display and Imaging Technology Innovation Center of Anhui Province, Academy of Optoelectronic Technology, Hefei University of Technology, Hefei 230009, China.
Flexible sensors mimic the sensing ability of human skin, and have unique flexibility and adaptability, allowing users to interact with intelligent systems in a more natural and intimate way. To overcome the issues of low sensitivity and limited operating range of flexible strain sensors, this study presents a highly innovative preparation method to develop a conductive elastomeric sensor with a cracked thin film by combining polydimethylsiloxane (PDMS) with multiwalled carbon nanotubes (MCNT). This novel design significantly increases both the sensitivity and operating range of the sensor (strain range 0-50%; the maximum tensile sensitivity of this sensor reaches 4.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
December 2024
Key Laboratory of Macromolecular Synthesis and Functionalization (Ministry of Education), Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; Center of Healthcare Materials, Shaoxing Institute, Zhejiang University, Shaoxing 312000, China. Electronic address:
Polymethacrylate and its derivatives are widely used in food industry and biomedical applications for their plasticity, biocompatibility and optical transparency. However, susceptibility to bacterial growth on their surfaces limits their applications. In this study, linear and branched polyethyleneimine (PEI) molecules were grafted onto poly(ethyl methacrylate) (PEMA) via aminolysis using a simple one-step method to enhance the antibacterial properties of PEMA films.
View Article and Find Full Text PDFBiosens Bioelectron
December 2024
Department of Cogno-Mechatronics Engineering, College of Nanoscience and Nanotechnology, Pusan National University, Busan, 46241, Republic of Korea. Electronic address:
Creatinine (Ctn) is a biomarker for chronic kidney disease (CKD). In this study, a highly sensitive and specific detection method for Ctn based on a molecularly imprinted polymer (MIP) based electrochemical biosensor was developed. Mxene (Mx), which has high absorption properties, was modified using carbon screen-printed electrodes (SPCE).
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