Papers by Keyword: Calixarene

Abstract: A new SPR sensor surface based onself-assembled-Calix [4] arene-derivative-monolayer was proposed for the detection of sodium in water. The immobisation of claixarene onto the gold surface was confirmed by impedance spectroscopy (EIS). Three alkaliions were used K⁺, Na⁺ and Ca²⁺ and the influence of pH on ions detection was studied and optimized. The Calix [4] arene-gold SPR sensor developed was characterized by low limit of detection (LOD) for about 10^-10 M, high sensitivity and wide linear detection range between 10^-6M and 10^-14M.

Abstract: Calixarene-based fluorenscent chemosenors, owing to its simplicity, high sensitivity and high detection limits for metal ions in biology and the environment, has been received much attention. Via cliking, calixarene derivations has the group of triazoles, which can bind to metol ions, but also can be modified by various fluorophores. This in-depth review provides an overview of calixarene-based fluorescent chemosensors for metal ions via clicking.

Abstract: This paper presents a effective approach for one new supermolecule function materia preparation, 25-(thioalkyl-alkoxy)-p-tertbutylcalix [4] arene with self-assembled monolayers character was synthesized by two-step nucleophilic substitute reaction in NaH-THF phase with p-tertbutylcalix [4] arene and dibromodecne . The structure of product was characterized by FT-IR, 1H NMR, 13C NMR and MALDI-TOF-MS. The self-assembly molecular imprinted film as the sensitive film was coated on the gold delay line of SAW sensors to detect for detecting organophosphorus compounds such as sarin, had important reference value in counter-terrorism.

Abstract: This paper presents new effective approachs for the supermolecule film deposition of surface acoustic wave (SAW) chemical sensors for detecting DMMP. 25-(thioalkyl-alkoxy)-p-tertbutylcalix [4] arene self-assembly molecular imprinted film as the sensitive film was coated on the gold delay line of SAW sensors to detect DMMP. The sensor has special response to organoosphorus compounds and the respond characteristic property in different temperatures of SAW sensor was studied in detail, had important reference value in counter-terrorism.

Abstract: Calixarenes are promising compounds to be used as ionophores and for molecular recognition. Their ability to form Langmuir and Langmuir-Blodgett (LB) films is of great interest in order to obtain small sensor devices which incorporate an active nanometric film. Calix[4]arene (Calix4) has been used in this work and its ability to form Langmuir films has been shown. Calix4 forms monolayers but at higher compressions tends to form multilayers. The presence of ions in the subphase, as lead chloride salt solutions, leads to some changes in the surface pressure-area (П-A) isotherms and surface potential-area (ΔV-A) isotherms. The effective dipole moments (μ) of the calixarene molecules in the uncomplexed and complexed states has been calculated from the ΔV values by using Helmholtz equation. Some characteristics of the films and mean molecular area have been deduced from the isotherms graph.

Abstract: In this study, we have fabricated 25-nm-pitched magnetic dot arrays using electron beam lithography (EBL), reactive ion etching (RIE) and ion-milling. We have used double mask method with calixarene resist and carbon film as a hard mask to transfer fine pattern to CoPt magnetic film. We transferred the calixarene resist dot arrays to carbon layer using O₂ gas in RIE as a first mask, then transferred the carbon dot arrays to CoPt magnetic layer as a second hard mask using ion-milling. We demonstrated that double mask method is very suitable to fabricate 25-nm-pitched magnetic dot arrays with a dot size of 18 nm and a height of 15 nm for patterned media with 1 Tb/in².

Abstract: Ultrathin separation membranes were prepared upon alternate electro-static layer-by-layer (lbl) adsorption of anionic p-sulfonatocalix-[arenes (calix8 and calix6) and cationic Polyvinylamine (PVA) polyelectrolytes on porous polyacrylonitrile/polyethylene terephthalate (PAN/PET) substrates. The permeation rates (P_R) of a variety of neutral and charged aromatic compounds across calix8/PVA and calix6/PVA membranes are investigated. The solutes were aniline (An), phenol (Ph), naphthalene (Np), alkali metal salts of benzene sulfonate (BS), naphthalene 2-sulfonate (NS) and benzene disulfonate (1, 3-BDS). For the neutral compounds, a size-selective transport was found. For charged aromatic compounds, the transport was both size-and charge-selective. Size and charge-selectivity lead to a separation factor α (Ph/1, 3-BDS) of 333.

Abstract: CoPt magnetic dot arrays with a fine pitch of 30 nm have been fabricated using electron beam (EB) lithography and ion milling. The possibility to ion-mill CoPt film using EB drawn calixarene resist pattern as a mask has been studied. We formed 30 nm pitch resist dot arrays with a dot diameter of 20 nm using 30-keV-EB lithography with calixarene resist. The resist dot arrays were ion-milled for 4 min using 200-eV Ar ion milling to fabricate CoPt dot arrays on a Si substrate. We fabricated fine pitched CoPt magnetic dot arrays with a diameter of 22-35 nm and a pitch of 30-150 nm. Results show that the ion-milled CoPt dot diameter increased with the dot pitch while the resist dot had a similar diameter of 20 nm.

Abstract: Using four types of calixarene derivatives (RCT, PCT, MRCT, TBCA) as coating materials, quartz crystal microbalance (QCM) sensors have been examined for detection of toxic formaldehyde gas indoors. The results showed that PCT was the most efficient adsorption coating material for host-guest recognition of formaldehyde molecule, when the coating mass was 43.93 μg. The PCT based QCM sensor possessed a linear response range of 109 ~ 2721 ppm formaldehyde gas. In comparison with gas chromatography method, the QCM sensor had a recovery of 97.98~104.59 % with a good reversibility, stability and reproducibility, showing that the PCT based QCM sensor can be well used for the determination of trace formaldehyde in the living environment.