Disclosure of Invention
The invention aims to provide a preparation method of an esterified cellulose loaded MXene high-toughness film, which not only simplifies the preparation process, but also ensures that the prepared ENCF @ MXene film has good wear resistance, water stability and biodegradability.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of an esterified cellulose loaded MXene high-toughness film comprises the following steps:
step 1, mixing LiF with 36% HCl solution at a ratio (1.02.0 g) to 40mL (1.02.0 g), and slowly adding Ti3AlC2Obtaining a solution A, then placing the solution A under a water bath condition and continuously stirring, finally performing centrifugal separation, and washing with deionized water to obtain an MXene suspension B;
step 2, soaking the poplar wood flour in NaOH solution, heating and stirring, performing centrifugal separation to obtain treated poplar wood flour, mixing choline chloride and oxalic acid according to a mass ratio of 7: 613 to obtain a mixture C, mixing the treated poplar wood flour with the mixture C according to a mass ratio of 1: 1520, heating and stirring until viscous liquid D is formed, and finally performing centrifugal separation according to a volume ratio of 1: (10-15) adding deionized water into the viscous liquid D to obtain a mixed solution E;
step 3, adding sodium chlorite and acetic acid into the mixed solution E according to the ratio of (23 g) to 1mL to 100mL, heating and stirring until the solution becomes milky white, filtering and washing to obtain esterified cellulose, and adding the esterified cellulose into distilled water to prepare esterified cellulose slurry with the concentration of 2025 mg/mL;
and 4, firstly, carrying out vacuum filtration on the MXene suspension B, drying, adding distilled water with a corresponding volume to prepare a suspension F with the concentration of 56 mg/mL, then adding the suspension F into the esterified cellulose slurry according to the volume ratio of 1: 34 to obtain a suspension G, carrying out ultrasonic dispersion treatment on the suspension G to obtain an esterified cellulose loaded MXene resin matrix, and finally preparing the esterified cellulose loaded MXene resin matrix into the ENCF @ MXene film.
Further, the temperature of the water bath in the step 1 is 45 ℃, and the stirring time is 24 hours.
Further, the pH value of MXene suspension B obtained in the step 1 is 67.
Further, the step 1 adopts a centrifuge with the rotating speed of 35004000 r/min for centrifugal separation.
Further, the concentration of the NaOH solution in the step 2 is 80100 mg/mL.
Further, in the step 2, the poplar powder is soaked in the NaOH solution at the heating temperature of 100 ℃ and the stirring time is 68 hours.
Further, the heating temperature of the mixture C of the processed poplar powder and the mixture C in the step 2 is 100120 ℃, and the stirring time is 3-5 hours.
Further, the heating temperature of the step 3 is 100 ℃, and the stirring time is 34 hours.
Further, in the step 4, the esterified cellulose loaded MXene resin matrix is prepared into the ENCF @ MXene film by adopting a suction filtration method, a casting method, a mould pressing method or a hot pressing method.
The invention has the following beneficial effects:
(1) according to the invention, the wood structure of poplar wood powder is firstly deconstructed by sodium hydroxide under the conditions of heating and stirring, lignin attached to cellulose and hemicellulose is partially dissolved and coated, then the simple heating, dissolving, filtering and cleaning treatment is carried out, unnecessary impurity removal steps are not needed, the preparation and processing technology is greatly simplified, the impurities are removed by simply adopting two-step dissolving and chlorine process bleaching, an ENCF @ MXene resin matrix can be obtained by adding MXene suspension into esterified cellulose pulp and then carrying out ultrasonic dispersion treatment, and finally the ENCF @ MXene film is prepared by adopting the existing film forming technology, so that the ENCF @ MXene film has very high economic benefit.
(2) The ENCF @ MXene film has good mechanical property due to the crosslinking and interlocking among cellulose micro/nano fibers through hydrogen bonds and van der Waals force action (the interaction between hydroxyl and carbonyl groups of esterified cellulose) and the formed reinforcing effect that the sheet layer MXene is uniformly dispersed among film laminated structures. Based on the self-reinforced compact layered structure of the ENCF @ MXene film, the slippage effect of MXene in the friction process enables the ENCF @ MXene film to have high surface strength and wear resistance. In addition, the surface of the ENCF @ MXene film has a compact cross-linked structure, water molecules are difficult to destroy the cross-linked structure formed by intertwining the micro-fibers and the nano-fibers, and the ENCF @ MXene film is not destructured even if being soaked in water for more than 3 months, so that the ENCF @ MXene film has good water stability.
(3) The raw material adopted by the invention is wood processing waste poplar powder, which is one of the most typical biomass green natural materials, and has the characteristics of wide source, large reserve and environmental protection; and the used solvent is green, environment-friendly and pollution-free, so that the ENCF @ MXene film can be degraded by microorganisms in a natural environment and converted into humus, can also be recovered, can be repeatedly used after being crushed, effectively realizes high-value utilization of waste wood, is environment-friendly and has sustainability.
Detailed Description
The following examples are given to illustrate the present invention in further detail, but are not intended to limit the scope of the present invention.
Example 1
A preparation method of an esterified cellulose loaded MXene high-toughness film comprises the following steps:
step 1, uniformly mixing 1g of LiF and 40mL of HCl aqueous solution with the mass fraction of 36%, and then slowly adding 1.5g of Ti3AlC2Obtaining a solution A, then placing the solution A under the condition of water bath at 45 ℃ and continuously stirring for 24 hours, finally carrying out centrifugal separation by adopting a centrifugal machine with the rotating speed of 3500r/min, and washing by using deionized water to obtain MXene suspension B with the pH value of 6;
step 2, soaking the poplar powder in 80mg/mL NaOH solution, stirring for 8 hours at 100 ℃, separating to obtain treated poplar powder, mixing 14g of choline chloride, 12g of oxalic acid and 2g of treated poplar powder, stirring for 3 hours at 110 ℃ until viscous liquid D is formed, and finally adding deionized water into the viscous liquid D according to the volume ratio of 1: 10 to obtain mixed solution E;
step 3, adding 2g of sodium chlorite and 1mL of acetic acid into 100mL of mixed solution E, stirring for 3 hours at the high temperature of 100 ℃ until the solution turns to milk white, filtering and washing to obtain esterified cellulose ENCF, and adding the esterified cellulose into distilled water to prepare esterified cellulose pulp with the concentration of 20 mg/mL;
and 4, filtering and drying the MXene suspension B in vacuum, adding distilled water to prepare a suspension F with the concentration of 5mg/mL, adding the suspension F into the esterified cellulose slurry according to the volume ratio of 1: 3 to obtain a suspension G, performing ultrasonic dispersion treatment on the suspension G for 30min to obtain an esterified cellulose loaded MXene resin matrix, and finally preparing the esterified cellulose loaded MXene resin matrix ENCF @ MXene by adopting a suction filtration method.
Example 2
A preparation method of an esterified cellulose loaded MXene high-toughness film comprises the following steps:
step 1, uniformly mixing 1g of LiF and 40mL of HCl aqueous solution with the mass fraction of 36%, and then slowly adding 1g of Ti3AlC2Obtaining a solution A, then placing the solution A in a water bath condition of 45 ℃ and continuously stirring for 24 hours, finally adopting a centrifuge with the rotating speed of 4000r/min to carry out centrifugal separation, and washing with deionized water to obtain an MXene suspension B with the pH value of 7;
step 2, soaking the poplar powder in 100mg/mL NaOH solution, stirring for 6 hours at 100 ℃, separating to obtain treated poplar powder, mixing 14g of choline chloride, 26g of oxalic acid and 4g of treated poplar powder, stirring for 4 hours at 100 ℃ until viscous liquid D is formed, and finally adding deionized water into the viscous liquid D according to the volume ratio of 1: 12 to obtain mixed solution E;
step 3, adding 2g of sodium chlorite and 1mL of acetic acid into 100mL of mixed solution E, stirring at the high temperature of 100 ℃ for 4 hours until the solution becomes milk white, filtering and washing to obtain esterified cellulose ENCF, and adding the esterified cellulose into distilled water to prepare esterified cellulose pulp with the concentration of 20 mg/mL;
and step 4, carrying out vacuum filtration on the MXene suspension B, drying, adding distilled water to prepare a suspension F with the concentration of 6mg/mL, adding the suspension F into the esterified cellulose pulp according to the volume ratio of 1: 3.5 to obtain a suspension G, carrying out ultrasonic dispersion treatment on the suspension G for 40min to obtain an esterified cellulose loaded MXene resin matrix, and finally carrying out suction filtration on the esterified cellulose loaded MXene resin matrix ENCF @ MXene to obtain the thin film.
Example 3
A preparation method of an esterified cellulose loaded MXene high-toughness film comprises the following steps:
step 1, uniformly mixing 2g of LiF and 40mL of HCl aqueous solution with the mass fraction of 36%, and then slowly adding 2g of Ti3AlC2Obtaining a solution A, then placing the solution A in a water bath condition of 45 ℃ and continuously stirring for 24 hours, and finally adopting the rotating speed ofCentrifuging by a 4000r/min centrifugal machine, and washing by deionized water to obtain MXene suspension B with the pH value of 6;
step 2, soaking poplar powder in 90mg/mL NaOH solution, stirring for 7 hours at 100 ℃, separating to obtain treated poplar powder, mixing 14g of choline chloride, 20g of oxalic acid and 2.8g of treated poplar powder, stirring for 5 hours at 120 ℃ until viscous liquid D is formed, and finally stirring according to the volume ratio of 1: 13 adding deionized water into the viscous liquid D to obtain a mixed solution E;
step 3, adding 3g of sodium chlorite and 1mL of acetic acid into 100mL of mixed solution E, stirring for 3 hours at the high temperature of 100 ℃ until the solution becomes milky white, filtering and washing to obtain esterified cellulose ENCF, and adding the esterified cellulose into distilled water to prepare esterified cellulose pulp with the concentration of 22 mg/mL;
and 4, filtering and drying the MXene suspension B in vacuum, adding distilled water to prepare a suspension F with the concentration of 6mg/mL, adding the suspension F into the esterified cellulose slurry according to the volume ratio of 1: 4 to obtain a suspension G, performing ultrasonic dispersion treatment on the suspension G for 50min to obtain an esterified cellulose loaded MXene resin matrix, and finally preparing the esterified cellulose loaded MXene resin matrix ENCF @ MXene by adopting a suction filtration method.
Example 4
A preparation method of an esterified cellulose loaded MXene high-toughness film comprises the following steps:
step 1, uniformly mixing 4g of LiF and 80mL of HCl aqueous solution with the mass fraction of 36%, and then slowly adding 4g of Ti3AlC2Obtaining a solution A, then placing the solution A in a water bath condition at 45 ℃, continuously stirring for 24 hours, and finally centrifuging and separating by adopting a centrifuge with the rotation speed of 3500r/min, and washing by using deionized water to obtain an MXene suspension B with the pH value of 7;
step 2, soaking poplar powder in 100mg/mL NaOH solution and stirring for 7 hours at 100 ℃, separating to obtain treated poplar powder, mixing 14g of choline chloride, 16g of oxalic acid and 2g of treated poplar powder, stirring for 5 hours at 100 ℃ until viscous liquid D is formed, and finally stirring according to the volume ratio of 1: 15 adding deionized water into the viscous liquid D to obtain a mixed solution E;
step 3, adding 3g of sodium chlorite and 1.5mL of acetic acid into 100mL of mixed solution E, stirring at the high temperature of 100 ℃ for 4 hours until the solution turns to milk white, filtering and washing to obtain esterified cellulose ENCF, and adding the esterified cellulose into distilled water to prepare esterified cellulose pulp with the concentration of 25 mg/mL;
and 4, filtering and drying the MXene suspension B in vacuum, adding distilled water to prepare a suspension F with the concentration of 5mg/mL, adding the suspension F into the esterified cellulose slurry according to the volume ratio of 1: 3 to obtain a suspension G, performing ultrasonic dispersion treatment on the suspension G for 60min to obtain an esterified cellulose loaded MXene resin matrix, and finally preparing the esterified cellulose loaded MXene resin matrix ENCF @ MXene by adopting a suction filtration method.
FIG. 1 is a structural simulation diagram of the ENCF @ MXene film prepared in example 1, wherein the uniformly dispersed esterified cellulose is intertwined and crosslinked, and the MXene is uniformly dispersed in a crosslinked network structure of the cellulose, and the adhesion strength of the sheet layer MXene on the esterified cellulose skeleton can be increased by suction filtration and film formation.
Fig. 2 is an SEM image of MXene prepared in example 1, and it is evident that MXene etched by this method has a layered structure similar to an accordion, and under the urging of energy, the carriers can move rapidly in the interlayer structure, which is helpful for the transfer of heat energy and imparts thermal conductivity to the insulating cellulose film.
FIG. 3 is an infrared spectrum of the ENCF and ENCF @ MXene films prepared in example 1, showing similar diffraction peaks in the infrared spectrum of the ENCF @ MXene compared to the esterified cellulose ENCF film, and a decrease in the diffraction intensity indicating that the MXene is dispersed and loaded into the cellulose backbone, thereby limiting the depth of detection of the infrared light.
FIG. 4 is a graph of the friction coefficient of the ENCF @ MXene film prepared in example 2 under different loads, wherein the friction coefficient under dry friction condition is very close to that under PAO lubricating oil dripping condition, which shows that MXene plays a key role in enhancing the mechanical property and surface property.
FIG. 5 is a graph of the wear scar topography under a light mirror for the ENCF @ MXene film prepared from example 2, which has a relatively flat surface, strong mechanical strength, and low wear rate.
FIG. 6 is a graph of the heat dissipation and temperature reduction of the ENCF @ MXene film prepared in example 3, compared with the esterified cellulose ENCF film, the ENCF @ MXene film has metal conductivity of transition metal carbide and excellent thermal conductivity due to the fact that MXene in the ENCF @ MXene film is loaded on a cellulose skeleton and hydroxyl groups or terminal oxygen are arranged on the surface of MXene material.
FIG. 7 is a graph showing the flexibility and foldability of the ENCF @ MXene film prepared in example 3, and it can be seen that the ENCF @ MXene film has excellent flexibility and does not break or break even when folded in half.
FIG. 8 is a stress-strain plot of the ENCF @ MXene film prepared in example 3 of the present invention having a higher tensile stress at break than the esterified cellulose ENCF film.