Carbon dioxide absorbent for fruit and vegetable storage and transportation, and preparation method thereof

Abstract

The invention discloses a carbon dioxide absorbent for fruit and vegetable storage and transportation, and a preparation method thereof, and belongs to the field of storage and transportation fresh-keeping of picked fruits and vegetables. The preparation method of the carbon dioxide absorbent comprises the following steps: introducing a specific type of organosilane to tetramethoxysilane which is a precuros step by step in order to synthesizes a hydrophobically-modified and amino area functionalized modified mesoporous silica support material, and loading organic amine on the pores and the surface of the support material to obtain the carbon dioxide absorbent. The absorbent which has strong hydrophobicity can significantly alleviate and eliminate the competitive adsorption of water vapor to carbon dioxide and the adverse effect on the adsorption stability in the high humidity environment of the fruit and vegetable storage and transportation, and the functional modification structure design of the amino area is used to highly disperse -NH2 in the outer layer of the material to realize easy contact with carbon dioxide in order to effectively improve the absorption capacity of carbon dioxide. The carbon dioxide absorbent has the advantages of strong absorption ability, long acting period, high adsorption selectivity, good use safety, high efficiency, greenness, and meeting the actual production demands of fruits and vegetables.

Description

technical field [0001] The invention belongs to the field of post-harvest storage, transportation and preservation of fruits and vegetables, and in particular relates to a mesoporous silicon oxide material loaded with organic amines by hydrophobic modification and amino region functional modification and a preparation method thereof. Background technique [0002] Post-harvest fruits and vegetables are still living organisms. During storage and transportation, they have been carrying out physiological metabolic activities mainly based on respiration, consuming oxygen and releasing carbon dioxide continuously. However, the excessive accumulation of carbon dioxide in the storage environment is likely to cause physiological diseases of fruits and vegetables, mainly manifested as browning inside and outside the tissue, brown spots, depressions, or tissue dehydration wilting and even the formation of cavities. Fruits and vegetables such as pears, fresh dates, Fuji apples, head let...

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Problems solved by technology

However, there is no report on the successful application of this type of carbon dioxide absorber to the storage and transportation of fruits and vegetables.

This is because, ① mesoporous silica materials have strong hydrophilicity (the surface contains a large amount of hydrophilic silanol groups), which can easily lead to excessive water loss during storage and transportation of some fruits and vegetables and affect the quality; ② in the storage and transportation of fruits and vegetables In a high-humidity environment (above 95% relative humidity), a large amount of high-concentration water vapor will be pre-adsorbed on the surface and pores of the hydrophilic mesoporous silica material, while the low-concentration carbon dioxide produced by fruit and vegetable respiration is difficult to penetrate. The permeable layer reacts with the loaded organic amine, thereby limiting its absorption of carbon dioxide; ③The thickness of the water layer adsorbed by the hydrophilic mesoporous silica material will continue to accumulate with the passage of storage time of fruits and vegetables, which will lead to The gradual decline of its absorption efficiency makes it unable to continue to play a stable role in the long-term storage of fruits and vegetables; ④The moisture content absorbed in the pores of the hydrophilic absorbent is too high, which is likely to cause the dissolution of the loaded organic amines and other chemical substances, polluting fruits and vegetables surface, affecting food safety

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