CN-121554212-B - MOF modified mineral fiber additive and preparation method and application thereof

CN121554212BCN 121554212 BCN121554212 BCN 121554212BCN-121554212-B

Abstract

The invention relates to the technical field of road engineering materials, in particular to a MOF modified mineral fiber additive, and a preparation method and application thereof. The additive comprises a mineral fiber matrix which is sequentially subjected to acid washing treatment and surface functionalization modification, and MOF which is loaded on the surface of the mineral fiber matrix through in-situ growth. The preparation method comprises the steps of carrying out ultrasonic cleaning and acid washing pretreatment on mineral fibers, carrying out surface modification by a silane coupling agent, and then growing an MOF functional layer on the surfaces of the fibers in situ. The fiber utilizes regular pore channels of MOF and adjustable surface chemistry to realize selective adsorption and inhibition of pollutants in VOCs and vehicle exhaust in the road service process in the asphalt construction stage, and meanwhile, the surface polar groups and the MOF rough porous layer synergistically improve the cohesiveness and dispersion stability of the fiber and asphalt interface, construct a uniform three-dimensional reinforcing network, improve the Marshall stability, water stability and dynamic stability of asphalt mixture, and improve the rutting resistance, crack resistance and fatigue resistance.

Inventors

LIU QUANTAO
WU JINYI
TANG JIN
LAN YING
DONG JIASHUN
WAN JIANG
ZHOU XINGPING
CHEN PENGXU
WU SHAOPENG

Assignees

武汉理工大学
中国十九冶集团有限公司

Dates

Publication Date: 20260512
Application Date: 20260121

Claims (7)

1. A method of preparing a MOF modified mineral fiber additive comprising the steps of: s1, carrying out acid washing pretreatment on mineral fibers; s2, carrying out surface modification on the mineral fibers subjected to acid washing by using a surface functionalization agent; S3, placing the surface-modified mineral fiber into a reaction solution containing metal salt, an organic ligand and a mineralizer for in-situ reaction; In the step S1, the pickling pretreatment is performed in an acid solution with a pH value of 3-4, wherein the acid solution comprises one or more of hydrochloric acid, acetic acid and citric acid; In the step S2, the surface functionalization agent comprises one or more of gamma-aminopropyl triethoxysilane, N-beta-amino ethyl-gamma-aminopropyl trimethoxysilane, carboxyethyl trimethoxysilane or carboxypropyl trimethoxysilane, and the surface functionalization agent is dissolved in water or ethanol to obtain a surface functionalization agent solution with the mass fraction of 0.5% -5%; and the MOF loading amount is 9.7% -31.8% based on the mass of the mineral fiber matrix.
2. The method according to claim 1, wherein in the step S3, the molar ratio of the metal cations, the organic ligand and the mineralizer in the metal salt is 1 (1-4): 0.24-4.8, and the mineralizer comprises one or more of hydrofluoric acid and acetic acid.
3. A MOF modified mineral fiber additive obtained by the preparation method according to any one of claims 1 to 2, comprising a mineral fiber matrix modified by acid washing treatment and surface functionalization in this order, and MOFs supported on the surface of the mineral fiber matrix by in-situ growth.
4. The MOF modified mineral fiber additive according to claim 3, wherein the MOF is comprised of a metal salt and an organic ligand, wherein the metal salt comprises one or more of a chromium salt, a zinc salt, a copper salt, or a zirconium salt, and wherein the mineral fiber comprises one or more of basalt fiber, diabase fiber, glass fiber, or rock wool fiber.
5. Use of the MOF modified mineral fiber additive of any one of claims 3 to 4 in asphalt mixtures.
6. The MOF modified mineral fiber asphalt concrete is characterized by comprising the MOF modified mineral fiber additive according to any one of claims 3-4, wherein the mixing amount of the additive is 0.2% -0.6% of the total mass of the asphalt mixture.
7. A method of preparing the MOF modified mineral fiber asphalt concrete of claim 6, comprising the steps of: A1, heating asphalt, and respectively heating coarse aggregate, fine aggregate and MOF modified mineral fiber additive; A2, uniformly mixing the coarse aggregate and the fine aggregate, adding asphalt, mixing, and finally adding the MOF modified mineral fiber additive, and mixing until uniform, thus obtaining the asphalt concrete.

Description

MOF modified mineral fiber additive and preparation method and application thereof Technical Field The invention relates to the technical field of road engineering materials, in particular to a MOF modified mineral fiber additive, and a preparation method and application thereof. Background Asphalt and modified asphalt thereof are widely applied to road engineering surface layers and base layers due to good cohesiveness and construction adaptability. Along with the improvement of traffic load and service life requirements, on one hand, pavement structures are required to have better rut resistance, crack resistance and fatigue resistance, and on the other hand, asphalt can release a certain amount of Volatile Organic Compounds (VOCs) and peculiar smell gases in the high-temperature technological processes of mixing, transporting, paving and the like, so that the influence on construction environment and personnel health is also gradually concerned. Therefore, how to improve road performance and meanwhile consider construction environment friendliness becomes a comprehensive problem to be solved by modifying asphalt materials. In the prior art, mineral fibers such as basalt fibers, diabase fibers and the like are widely used in asphalt or asphalt mixtures as anti-cracking toughening materials, and the anti-cracking and anti-fatigue properties of the structure are improved through fiber bridging and drawknot actions. However, many of these mineral fibers are directly doped in a physical manner, the surface of the fiber is mainly an inert metal oxide or silica skeleton, the polarity of the interface is fixed, the interface lacks of a controllable functional group, the compatibility with the asphalt matrix mainly containing hydrocarbons is limited in terms of wettability and cohesiveness, the problems of fiber aggregation, uneven dispersion, insufficient interfacial adhesion and the like are easy to occur, a three-dimensional toughening network is difficult to fully form, the anti-cracking toughening effect cannot be effectively exerted, and any function related to VOCs is not endowed to the fiber. Some patents exist for carrying out interface modification on asphalt or fiber by adding compatilizer, resin or coupling agent, and mainly aiming at improving mechanical property and bonding effect, mineral fiber is still regarded as a single mechanical reinforcing phase, and control of construction odor and VOCs emission is not considered. In the aspect of odor control, the plant extract, the odor masking agent or the inorganic adsorbent adopted in the prior art has obvious defects that the former can only mask odor but can not eliminate VOCs, and the latter is easy to agglomerate in an asphalt system to form stress concentration points, so that the low-temperature performance of the material and the stability between asphalt are seriously impaired. More importantly, the odor removing or adsorbing component and the mineral fiber reinforcing system are mutually independent, the doping amount and the process are required to be designed respectively, the formula is complex, the structural reinforcement and the VOCs control are respectively different additives, and the integrated technical scheme of cracking resistance, toughening and odor removing adsorption is not formed on the same mineral fiber carrier at the same time. In addition, with the development of porous functional materials, metal-organic framework materials (metal-organic frameworks, MOFs) have been used as functional adsorption phases in the fields of gas adsorption, air purification and the like as a novel material with a large specific surface area and an adjustable pore structure, and related patents are mostly developed around filter materials or fixed bed adsorption structures. In the prior art, MOF is usually used in the form of independent powder or coating, mainly focuses on the adsorption performance, does not design the structure and interface aiming at the working condition characteristics of high-temperature, high-viscosity and strong-shearing systems such as asphalt, and does not organically combine MOF with mineral fibers such as basalt fibers, diabase fibers and the like in a surface chemical mode, so that the mineral fibers have stable porous adsorption function while bearing the anti-cracking and toughening effects. Therefore, there is a need to develop a new asphalt mix functional additive that can improve the structural stability of the system, improve the comprehensive road performance and reduce the odor emission to meet the requirements of high quality and green applications. Disclosure of Invention In view of the above, the invention provides a MOF modified mineral fiber additive, and a preparation method and application thereof. By introducing polar active groups such as-NH 2 and-COOH on the surface of mineral fibers and constructing an MOF porous functional layer with regular pore channels and adjustable chemical sites on the sur