Nicotine, a natural alkaloid, is widely present in tobacco and has had a long history with humans. In recent years, nicotine salts have emerged as an innovative technology, garnering significant attention. This article will explore the origins, relationships, and applications of nicotine and nicotine salts in the e-cigarette industry.
I. The Origins of Nicotine and Nicotine Salts
Nicotine:
Nicotine is an alkaloid that is broadly present in the nightshade family of plants, such as tobacco, and is an organic compound. It exists not only in tobacco leaves but also in the fruits of other nightshade plants like potatoes, tomatoes, and goji berries, with tobacco having the highest nicotine content.
Nicotine can enhance concentration, suppress hunger, and relieve stress, providing pleasure to smokers but also has addictive properties. It is the most important chemical substance in tobacco.
At room temperature, nicotine is a colorless, oily liquid that can completely dissolve in water and alcohol. It has a strong, distinctive smell and emits a typical tobacco aroma in its pure form.
In the early stages of e-cigarettes, nicotine was directly added to the e-liquid due to its volatile nature, which allows it to efficiently transition from liquid to gas when heated. However, nicotine can irritate the mouth, nose, and throat, leading to a poor user experience and low absorption efficiency, which limited the further development of the e-cigarette market.
Nicotine Salts:
Nicotine salts are salts formed by the reaction of nicotine with acids, though they are not traditional “salts” but rather crystals formed through an organic salt reaction. The greatest significance of nicotine salts lies in solving the efficiency of nicotine transportation in the blood.
In 2015, the American company JUUL invented nicotine salt technology. This technology involves the production of nicotine salts by a neutralization reaction between nicotine and organic acids, then adding these salts to the e-liquid. The invention of nicotine salts has provided a smoother taste and better absorption of aerosols, significantly enhancing the transport and absorption rate of nicotine in the body.
After the invention of nicotine salts, the conversion rate of smokers to e-cigarettes in the U.S. increased fivefold, changing the smoking habits of 30% of American smokers. The innovation of nicotine salt technology has brought new possibilities to the e-cigarette industry and improved the experience for smokers.
II. Synthesis and Application of Nicotine Salts
Synthesis of Nicotine Salts:
This is an example of forming nicotine benzoate by having free base nicotine mix with benzoic acid in a solution. Once in the same solution, protons from the benzoic acid dissociate and bind to the nitrogen groups in the nicotine molecules, forming a protonated form of nicotine. This mixture of protonated nicotine and deprotonated benzoic acid constitutes “nicotine salts,” which in this case is nicotine benzoate.
Production and Application of Nicotine Salt E-Liquid:
The formula includes 2-10 parts of the prepared nicotine salt, 50-100 parts of propylene glycol, 50-100 parts of glycerol, and 1-5 parts of essential oils.
III. Differences Between Nicotine and Nicotine Salts:
Absorption Speed:
Nicotine salts are absorbed into the bloodstream extremely quickly, typically within 6 seconds, designed to mimic the rapid hit of nicotine experienced during smoking. This rapid absorption and metabolism allow users to quickly alleviate cravings and reduce smoking frequency. In contrast, nicotine has a slower absorption process, and its peak and decline are also slower.
Taste and Throat Hit:
High concentrations of nicotine may bring a peppery spiciness, affecting the overall flavor of the e-liquid and possibly causing throat discomfort. In contrast, due to their closer-to-neutral pH value, nicotine salts, even at high concentrations, are milder on the throat and do not negatively impact the flavor of the e-liquid.
IV. Development Directions and Trends for Nicotine Salts:
Acid Selection and Optimization:
The three most common acids used in the synthesis of nicotine salts are lactic acid, benzoic acid, and acetylpropionic acid. Benzoic acid is the most commonly used. Future technological innovations may focus on finding more suitable acids or optimizing the performance of existing ones, including improving the selectivity of acids for nicotine, enhancing reaction efficiency, and reducing by-products. Moreover, exploring new types of acids or catalysts to achieve more efficient synthesis of nicotine salts may be pursued.
Enhancing the Purity of Nicotine Salts:
Enhancing purity is a key goal in the development of nicotine salts, aiming to develop more efficient and precise separation and purification techniques to remove potential impurities and enhance the purity of nicotine salts. This would allow for a better throat hit and satisfaction under legal nicotine concentration conditions, helping smokers better adapt to low-nicotine e-cigarettes.
Composite Nicotine Salt Technology:
This emerging research direction focuses on deeply studying the properties of nicotine salts formed by the combination of organic acids and nicotine, to precisely calculate and optimize the ratio of acid to nicotine, thus achieving better taste and transport efficiency. The core of this technology lies in understanding the interactions between different organic acids and nicotine and how these interactions affect the chemical properties, physical form, and sensory experience of nicotine salts.
In conclusion, the technological innovation directions for nicotine salts are diverse, aimed at enhancing their purity, optimizing taste, boosting stability, and meeting the diverse needs of consumers. These innovations will help promote the broader application and development of nicotine salts in the e-cigarette industry.