CN1302987C

CN1302987C - Surface-activated carbon fiber and its preparation method

Info

Publication number: CN1302987C
Application number: CNB200410077670XA
Authority: CN
Inventors: 安小宁
Original assignee: South China University of Technology SCUT
Current assignee: East China University of Science and Technology; South China University of Technology SCUT
Priority date: 2004-12-28
Filing date: 2004-12-28
Publication date: 2007-03-07
Anticipated expiration: 2024-12-28
Also published as: CN1657408A

Abstract

The present invention relates to a preparation method for carbon fibers with activated surfaces. Carbon fibers are dipped into a cerium salt solution, and are oscillated and activated for 5 to 30 minutes. Then, the cerium salt solution is drained, and the carbon fibers are washed by an acid solution. The carbon fibers are washed to neutrality by deionization, and are dried in vacuum to obtain the carbon fibers with active surfaces. The concentration of the cerium salt solution is 1.0 to 10 g/L, and a weight and volume ratio (grams for weight; milliliters for volumes) of solid and liquid of the carbon fibers and the cerium salt solution is 1 to 50 to 1 to 100. Cerate carbon oxide fibers are used, the content of oxygen containing groups of treated carbon fiber surfaces is increased, surface activity is increased and thus adsorption quantities of heavy metal ions and formaldehyde of the carbon fibers are evidently enhanced. The present invention has the advantages of simplicity, short reaction time, no pollution and industrialization continuous treatment, and has wide application prospects in the technical fields of carbon fiber production, environmental protection, etc.

Description

Carbon fiber of surface active and preparation method thereof

Technical field

The present invention relates to carbon fiber of a kind of surface active and preparation method thereof.

Background technology

Carbon fiber is the fibrous activated carbon material of superior performance; have flourishing specific surface area, narrower pore size distribution, adsorption/desorption speed and bigger loading capacity faster; can be processed as different shapes such as felt, cloth, paper; corrosion resistance nature is strong, and activated carbon fiber and series product thereof are used widely in fields such as environment protection, catalysis, medicine, military projects.

Carbon fiber surface is carried out activation treatment can significantly improve its adsorption activity, adopt activation methods such as steam activation method, oxygen method, zinc oxide method, phosphoric acid method, sulfuric acid process, nitrate method, potassium permanganate process, hydrogen peroxide method, hydroxide nanofarad and electrochemical oxidation process to increase the surfactivity of carbon fiber usually.Therefore, consider from the factor of aspects such as economy and environmental protection, seeks a kind of efficiently, economy, safety, the little activation method of pollution are still needs the problem that solves in the carbon fiber production.

Summary of the invention

Purpose of the present invention provides a kind of preparation method of carbon fiber of surface active, by selecting cerium salt carbon oxide fiber for use, handles back carbon fiber surface oxy radical content and increases, and surfactivity increases, and carbon fiber significantly improves the adsorptive capacity of heavy metal ion and formaldehyde.

The present invention also aims to provide the carbon fiber of the surface active of described method preparation.

The preparation method of the carbon fiber of surface active of the present invention immerses carbon fiber in the cerium solution, vibration activation 5 to 30 minutes, and drop removes cerium solution, washs carbon fiber with acid solution, spends ion-cleaning again to neutral, and vacuum-drying obtains the carbon fiber of surface active;

Cerium solution concentration is 1.0～10g/L, and the solid-liquid weight and volume of carbon fiber and cerium solution is than (weight, gram; Volume, milliliter) be 1: 50～1: 100.

The preparation method of the carbon fiber of surface active is characterized in that: used cerium salt is ceric ammonium nitrate, ammonium cerous sulfate or cerous acetate.

Preferred plan: carbon fiber is immersed in the cerium solution, and in 30 ℃ of following constant temperature vibration activation 5 to 30 minutes, drop removed cerium solution, sulphuric acid soln washing carbon fiber with 1% 3 times, spend ion-cleaning again to neutral,, obtain the carbon fiber of surface active 100 ℃ of vacuum-dryings 24 hours.

The functional group of the invention described above method activatory carbon fiber surface adopts X-ray photoelectron spectroscopy to determine, specific surface area is calculated with standard BET method, microvoid structure adopts the analysis of T-method, heavy metal ion adsorbed capacity adopts the ICP-aes determination, formaldehyde adopts 4-amino-3-hydrazine-5-sulfydryl-1,2,4-triazole spectrophotometry (being called for short AHMT).

Carbon fiber surface treatment method of the present invention is simple, and the reaction times is short, and is pollution-free, but and industrialization handle continuously, have broad application prospects in fields such as carbon fiber production and environment protection.

Description of drawings

Fig. 1 be carbon fiber the central hole structure parameter (●: activated carbon fibre not, ■: the inventive method activatory carbon fiber)

Fig. 2 is the loading capacity (★: activated carbon fibre not, ■: the inventive method activatory carbon fiber) of carbon fiber PARA FORMALDEHYDE PRILLS(91,95)

Embodiment

Embodiment 1

The carbon fiber (CF) of 1.0g after the vacuum constant weight immersed in the ceric ammonium nitrate solution of 50ml, 10g/L, and in 30 ℃ of following constant temperature vibration activation 5 minutes, drop removed cerium solution.Sulphuric acid soln washing carbon fiber with 1% 3 times spends ion-cleaning again to neutral.100 ℃ of vacuum-dryings 24 hours, obtain the carbon fiber (ACF) of surface active.

The specific surface area of the carbon fiber that obtains surface active (ACF) of method for preparing is calculated with standard BET method, and its result is as shown in table 1.S in the table _BETBe specific surface area, S _MicBe micropore area, V _MicBe micro pore volume, V _tBe total pore volume, MPD is a mean pore size.Table 1 result shows that change has taken place carbon fiber activation rear surface structure.

Table 1

Title	S _BET (m ²/g)	S _mic (m ²/g)	V _t (ml/g)	V _mic (ml/g)	MPD (nm)
Title	S _BET (m ²/g)	S _mic (m ²/g)	V _t (ml/g)	V _mic (ml/g)	MPD (nm)	CF ACF	1086.2 987.4	903.1 773.5	0.5778 0.4896	0.4520 0.3761	1.94 1.94

Embodiment 2

The carbon fiber (CF) of 1.0g after the vacuum constant weight immersed in the ammonium cerous sulfate solution of 80ml, 8.5g/L, and in 30 ℃ of following constant temperature vibration activation 15 minutes, drop removed cerium solution.Sulphuric acid soln washing carbon fiber with 1% 3 times spends ion-cleaning again to neutral.100 ℃ of vacuum-dryings 24 hours, obtain the carbon fiber (ACF) of surface active.

The microvoid structure of the carbon fiber that obtains surface active (ACF) of method for preparing adopts the analytical calculation of T-method, and its result as shown in Figure 1.Fig. 1 result shows that carbon fiber activation rear surface structure is mainly based on central hole structure.

Embodiment 3

The carbon fiber (CF) of 1.0g after the vacuum constant weight immersed in the ceric ammonium nitrate solution of 100ml, 6.5g/L, and in 30 ℃ of following constant temperature vibration activation 30 minutes, drop removed cerium solution.Sulphuric acid soln washing carbon fiber with 1% 3 times spends ion-cleaning again to neutral.100 ℃ of vacuum-dryings 24 hours, obtain the carbon fiber (ACF) of surface active.

The functional group content on the carbon fiber that obtains surface active (ACF) surface of method for preparing adopts X-ray photoelectron spectroscopy to measure, and its result is as shown in table 2.After the activation of table 2 explanation carbon fiber, its surface contains oxygen functional group content obviously to be increased.

Table 2

Title	Functional group content (at.%)			C (at.％)	O/C (at.)
	Functional group content (at.%)					-C-OH	-C＝O	-COOH
	CF ACF	16.9 21.6	4.48 9.05			-C-OH	-C＝O	-COOH	3.73 7.37	80.9 59.3	0.181 0.562

Embodiment 4

The carbon fiber (CF) of 1.0g after the vacuum constant weight immersed in the cerous acetate solution of 60ml, 2.5g/L, vibration activation 10 minutes, drop removes cerium solution.Sulphuric acid soln washing carbon fiber with 4% spends ion-cleaning again to neutral.90 ℃ of vacuum-dryings 20 hours, obtain the carbon fiber (ACF) of surface active.

Carbon fiber is selected Pb for use to the loading capacity of metal ion ²⁺, Cu ²⁺And Ni ²⁺Measure, experimental technique is as follows: use 50mL respectively, the Pb of 0.1M ²⁺, Cu ²⁺And Ni ²⁺Solution equilibria 0.1g carbon fiber (CF and ACF) 15 minutes, the carbon fiber of Filtration Adsorption metal ion (CF and ACF), and use the deionized water washed twice.Filtrate and washings are recovered in the 250mL volumetric flask, and are diluted to scale with deionized water.The metal ion of absorption does not adopt the ICP-aes determination.Can extrapolate the loading capacity (mg/g) of carbon fiber (CF and ACF) by calculating the amount of metal ion of not adsorbing, its result is as shown in table 3.After the activation of table 3 explanation carbon fiber, its loading capacity to metal ion has big raising.

Table 3

Title	Loading capacity (mg/g)
	Loading capacity (mg/g)			Pb ²⁺	Cu ²⁺	Ni ²⁺
	CF ACF	15.6 36.8	7.60 20.2	Pb ²⁺	Cu ²⁺	Ni ²⁺	5.61 13.5

Embodiment 5

The carbon fiber (CF) of 1.0g after the vacuum constant weight immersed in the ammonium cerous sulfate solution of 100ml, 1.0g/L, and in 30 ℃ of following constant temperature vibration activation 5 minutes, drop removed cerium solution.Sulphuric acid soln washing carbon fiber with 1% 3 times spends ion-cleaning again to neutral.100 ℃ of vacuum-dryings 24 hours, obtain the carbon fiber (ACF) of surface active.

Adopt nitrogen bubbling law will contain 100ppm formaldehyde, flow is 0.5cm ³The nitrogen gas stream of/s is under 30 ℃ condition, by long 3 centimetres, 1 centimetre of diameter and carbon fiber (ACF) chromatographic column that makes as stated above is housed, make absorption liquid with Sodium Metabisulfite, make it generate the formaldehyde of hydroxyl METHAPHOSPHORIC ACID not adsorb in the fixed gases, adopt 4-amino-3-hydrazine-5-sulfydryl-1,2,4-triazole spectrophotometry (being called for short AHMT) formaldehyde content.Can extrapolate the loading capacity (mg/g) of carbon fiber (CF and ACF) by calculating the formaldehyde amount of not adsorbing, its result as shown in Figure 2.After Fig. 2 illustrated the carbon fiber activation, the loading capacity of its PARA FORMALDEHYDE PRILLS(91,95) had big raising.

Claims

1, a kind of preparation method of carbon fiber of surface active is characterized in that, carbon fiber is immersed in the cerium solution, vibration activation 5 to 30 minutes, drop removes cerium solution, washs carbon fiber with acid solution, spend ion-cleaning again to neutral, vacuum-drying obtains the carbon fiber of surface active;

Cerium solution concentration is 1.0～10g/L, the solid-liquid weight and volume of carbon fiber and cerium solution than by weight for gram and volume for milliliter the time be 1: 50～1: 100.

2, the preparation method of the carbon fiber of surface active according to claim 1 is characterized in that: used cerium salt is ceric ammonium nitrate, ammonium cerous sulfate or cerous acetate.

3, the preparation method of the carbon fiber of surface active according to claim 1 and 2, it is characterized in that: carbon fiber is immersed in the cerium solution, in 30 ℃ of following constant temperature vibration activation 5 to 30 minutes, drop removes cerium solution, sulphuric acid soln washing carbon fiber with 1% 3 times, spend ion-cleaning again to neutral,, obtain the carbon fiber of surface active 100 ℃ of vacuum-dryings 24 hours.