The synthesis and luminous characteristics of water -soluble cellulose ether/EU (III)

Synthetic water -soluble cellulose ether/EU (III) with luminous performance, namely, carboxymethyl cellulose (CMC)/EU (III), methyl cellulose (MC)/EU (III), and Hydroxyeyl cellulose (HEC)/EU (III) discusses the structure of these complexs and is confirmed by FTIR. The launch spectrum of these matched objects is EU (III) at 615nm. Electric puppet transition (by 5D0 → 7F2). The replacement of CMC affects the fluorescent spectrum and strength of CMC/EU (III). The EU (III) content also affects the fluorescent strength of the complex. When the EU (III) content is 5%(mass ratio), the fluorescent strength of these water -soluble cellulose ether EU (III) matches reached the maximum.

Keywords: water -soluble cellulose ether; Eu (III); matched; glowing

1.Introduction

Cellulose is a linear macrometer of the β-D glucose unit connected by the (1,4) alcohol. Because of its renewable, biodegradable, biocompatibility, the study of cellulose is increasing The more watched. Cellulose is also used as a compound of optical, electrical, magnetic, and catalytic performance as a multi -official group’s alkyr oxygen ligand. Y.OKAMOTO and collaborators have studied preparation tests and applications containing rare earth metal ion polymers. They observed that the CMC/TB matched compuer has a strong round polarizing fluorescent. CMC, MC, and HEC, as the most important and widely used cellulose water -soluble cellulose, have received great attention due to their good solubility performance and extensive application value, especially the fluorescent labeling technology The structure of cellulose in the aqueous solution is very effective.

This article reports a series of water -soluble cellulose ether, namely the preparation, structure and fluorescent properties formed by the matomoid formed by CMC, MC and HEC and EU (III).

2. Experiment

2.1 Experimental materials

CMC (degree of substitution (DS) is 0.67, 0.89, 1.2, 2.4) and HEC are kindly provided by KIMA CHEMICAL CO.,LTD.

MC (DP=450, viscosity 350~550mpa·s) is produced by KIMA CHEMICAL CO.,LTD. Eu2O3 (AR) is produced by Shanghai Yuelong Chemical Factory.

2.2 Preparation of CMC (HEC, MC) /Eu(III)complexes

EuCl3 · 6H2O solution (solution A): dissolve Eu2Os in 1:1 (volume ratio) HCI and dilute to 4. 94X 10-2 mol/L.

CMC/Eu(III) complex solid state system: Dissolve 0.0853g of CMC with different DSs in water, then add quantitative Eu(III) dropwise to its aqueous solution, so that the mass ratio of CMC:Eu(III) is 19: 1. Stir, reflux for 24 hours, rotary evaporate to dryness, vacuum dry, grind to powder with agate mortar.

CMC (HEC, MC/Eu(III) aqueous solution system: Take 0.0853 g of CMC (or HEC or MC)) sample and dissolve it in H2O, then add different amounts of solution A (to prepare different Eu(III) Concentration complex), stirred, heated to reflux, moved to a certain amount of volumetric flask, added distilled water to dilute to the mark.

2.3 Fluorescence spectra of CMC (HEC, MC) /Eu(III) complexes

All complex aqueous systems were measured with RF-540 fluorescence spectrophotometer (Shimadzu, Japan). The CMC/Eu(III) solid-state system was measured with a Hitachi MPE-4 fluorescence spectrometer.

2.4 Fourier transform infrared spectroscopy of CMC (HEC, MC) /Eu(III)complexes

The FTIR IR of the complex was solidified with Aralect RFX-65AFTIR and pressed into KBr tablets.

3. Results and Discussion

3.1 Formation and structure of CMC (HEC, MC) /Eu(III) complexes

Due to electrostatic interaction, CMC is in equilibrium in a dilute aqueous solution, and the distance between the CMC molecular chains is far away, and the mutual force is weak. When Eu(III) is added dropwise into the solution, the CMC molecular chains in the solution The conformational properties are all changed, the electrostatic balance of the initial solution is destroyed, and the CMC molecular chain tends to curl. When Eu(III) combines with the carboxyl group in CMC, the bonding position is random (1:16), Therefore, in a dilute aqueous solution, Eu(III) and CMC are randomly coordinated with the carboxyl group in the chain, and this random bonding between Eu(III) and CMC molecular chains is unfavorable for strong fluorescence emission, because it Make part of the chiral position disappear. When the solution is heated, the movement of CMC molecular chains is accelerated, and the distance between CMC molecular chains is shortened. At this time, the bonding between Eu(III) and the carboxyl groups between CMC molecular chains is easy to occur.

This bonding is confirmed in the CMC/Eu(III) FTIR spectrum. Comparing curves (e) and (f), the 1631cm-1 peak in curve (f) weakens in (e), and two new peaks 1409 and 1565cm-1 appear in curve (e), which are a COO – Base vs and vas, that is, CMC/Eu(III) is a salt substance, and CMC and Eu(III) are mainly bound by ionic bonds. In the curve (f), the 1112cm-1 peak formed by the absorption of the aliphatic ether structure and the broad absorption peak at 1056cm-1 caused by the acetal structure and hydroxyl are narrowed due to the formation of complexes, and fine peaks appear. The lone pair electrons of the O atom in C3-O and the lone pair electrons of the O atom in ether did not participate in the coordination.

Comparing the curves (a) and (b), it can be seen that the bands of MC in MC/Eu(III), whether it is the oxygen in the methoxyl group or the oxygen in the anhydrous glucose ring, change, which shows that in MC All oxygens are involved in coordination with Eu(III).

3.2 Fluorescence spectra of CMC (HEC, MC) /Eu(III) complexes and their influencing factors

3.2.1 Fluorescence spectra of CMC (HEC, MC) /Eu(III) complexes

Since water molecules are effective fluorescence quenchers, the emission intensity of hydrated lanthanide ions is generally weak. When Eu(III) ions are coordinated with water-soluble cellulose ether, especially with polyelectrolyte CMC molecules, part or all of the coordinated water molecules can be excluded, and the emission intensity of Eu(III) will be enhanced as a result. The emission spectra of these complexes all contain the 5D0→7F2 electric dipole transition of Eu(III) ion, which produces a peak at 618nm.

3.2.2 Factors affecting the fluorescence properties of CMC (HEC, MC) /Eu(III) complexes

The properties of cellulose ethers affect the fluorescence intensity, for example, the complexes CMC/Eu(III) formed by different DSs have different fluorescence properties. When the DS of CMC is not 0.89, the fluorescence spectrum of the complex of CMC/Eu(III) only has a peak at 618nm, but when the DS of CMC is 0.89, within the range of our experiment, solid CMC/Eu(III) III) There are two weaker emission peaks in the emission spectrum, they are the magnetic dipole transition 5D0→7F1 (583nm) and the electric dipole transition 5D0→7F3 (652nm). In addition, the fluorescence intensities of these complexes are also different. In this paper, the emission intensity of Eu(III) at 615nm was plotted against the DS of CMC. When the DS of CMC=0.89, the light intensity of solid-state CMC/Eu(III) reaches the maximum. However, the viscosity (DV) of CMC has no effect on the fluorescence intensity of the complexes within the scope of this study.

4 Conclusion

The above results clearly confirm that the complexes of water-soluble cellulose ether/Eu(III) have fluorescence emission properties. The emission spectra of these complexes contain the electric dipole transition of Eu(III), and the peak at 615nm is caused by Produced by the 5D0→7F2 transition, the nature of cellulose ether and the content of Eu(III) can affect the fluorescence intensity.