A high temperature solution processing method was adapted to prepare durable, freestanding, submicrometer thickness films for transmission infrared spectroscopy studies of ionomer membrane. The materials retain structural integrity following cleaning and ion-exchange steps in boiling solutions, similar to a commercial fuel cell membrane. Unlike commercial membrane, which typically has thicknesses of >25 μm, the structural properties of the submicrometer thickness materials can be probed in mid-infrared spectral measurements with the use of transmission sampling. Relative to the infrared attenuated total reflection (ATR) technique, transmission measurements can sample ionomer membrane materials more uniformly and suffer less distortion from optical effects. Spectra are reported for thermally processed Nafion and related perfluoroalkyl ionomer materials containing phosphonate and phosphinate moieties substituted for the sulfonate end group on the side chain. Band assignments for complex or unexpected features are aided by density functional theory (DFT) calculations.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ac301662f | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Mechanically Stable and Damage Resistant Freestanding Ultrathin Silver Nanowire Films with Closely Packed Crossed-Lamellar Structure.
Precis Chem
December 2024
Department of Chemistry, New Cornerstone Science Laboratory, Institute of Biomimetic Materials & Chemistry, Anhui Engineering Laboratory of Biomimetic Materials, Division of Nanomaterials & Chemistry, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China.
One-dimensional (1D) functional nanowires are widely used as nanoscale building blocks for assembling advanced nanodevices due to their unique functionalities. However, previous research has mainly focused on nanowire functionality, while neglecting the structural stability and damage resistance of nanowire assemblies, which are critical for the long-term operation of nanodevices. Biomaterials achieve excellent mechanical stability and damage resistance through sophisticated structural design.
View Article and Find Full Text PDFPreliminary study on the preparation of lyophilized acellular nerve scaffold complexes from rabbit sciatic nerves with human umbilical cord mesenchymal stem cells.
World J Stem Cells
December 2024
Department of Orthopedics, Children's Hospital of Fudan University & National Children's Medical Center, Shanghai 201102, China.
Background: The gold standard of care for patients with severe peripheral nerve injury is autologous nerve grafting; however, autologous nerve grafts are usually limited for patients because of the limited number of autologous nerve sources and the loss of neurosensory sensation in the donor area, whereas allogeneic or xenografts are even more limited by immune rejection. Tissue-engineered peripheral nerve scaffolds, with the morphology and structure of natural nerves and complex biological signals, hold the most promise as ideal peripheral nerve "replacements".
Aim: To prepare allogenic peripheral nerve scaffolds using a low-toxicity decellularization method, and use human umbilical cord mesenchymal stem cells (hUC-MSCs) as seed cells to cultivate scaffold-cell complexes for the repair of injured peripheral nerves.
An innovative method for preparing durable flame-retardant cotton fabrics using tetrakis(hydroxymethyl)phosphonium sulfate without specialized equipment.
Int J Biol Macromol
December 2024
State Key Laboratory of Resource Insects, College of Sericulture Textile and Biomass Sciences, Southwest University, Chongqing 400715, China. Electronic address:
In this study, two phosphorus-based flame retardants diethylenetriamine trimethyl diphosphonate lysine (APTA) and a tetrakis(hydroxymethyl)phosphonium sulfate prepolymer with urea (DUPT) were synthesized. The structures of these compounds were characterized via nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR). FTIR and scanning electron microscopy (SEM) analyses revealed that DUPT crosslinked APTA onto cellulose, which was pre-processed with diethylenetriamine dipropylene oxide (NAED) to introduce NH groups through PCN bonds.
View Article and Find Full Text PDFHigh-fiber content composites produced from mixed textile waste: Balancing cotton and polyester fibers for improved composite performance.
Int J Biol Macromol
December 2024
Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, FI-00076 Espoo, Finland.
This study investigates the effect of fibers from cotton and polyester textiles on the properties of fiber-reinforced polypropylene (PP) composites aimed at durable and load-bearing materials. Herein we developed a process-centered strategy to introduce 52 wt% of fibers within the thermoplastic matrix, while ensuring proper interfacial coupling. We examined the mechanical, thermal, and rheological properties of composite materials that integrated cotton and polyester waste fibers into PP matrices with different coupling agents.
View Article and Find Full Text PDFInterfacial functionalization and capillary force welding of enhanced silver nanowire-cellulose nanofiber composite electrodes for electroluminescent devices.
Int J Biol Macromol
December 2024
Plant Fiber Material Science Research Center, State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou 510640, PR China; Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangzhou 510640, PR China.
The development of flexible, intelligent, and lightweight optoelectronic devices based on flexible transparent conductive electrodes (FTCEs) utilizing silver nanowires (AgNWs) has garnered increasing attention. However, achieving low surface resistance, strong adhesion to the flexible substrate, low surface roughness, and green degradability remains a challenge. Here, a composite electrode combining natural polymer cellulose nanofibers (TCNFs) with AgNWs was prepared.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!