## 1 Introduction  
The studies of interactions between surfactants and bioactive molecules are of enormous importance because of their applications in biological systems, pharmaceuticals, and biotechnological processes [1, 2]. Surfactants are fascinating compounds because of their amphiphilic nature, hence they possess both hydrophilic and hydrophobic characteristics in the same mixtures and have soluble properties in polar and non-polar solvents [3]. Surfactants have the ability to form aggregates at a particular concentration in both aqueous and non-aqueous media. The concentration, at which the aggregation originates, is known as critical micelle concentration [CMC], and the aggregate is called a micelle. The phenomenon of aggregation in molecules incorporates both attractive and repulsive interactions. The nature of hydrophilic and hydrophobic moieties determines how bio-active compounds interact during formulation, aggregation and biological point of view in drug -surfactant interactions. Because of the presence of substituents on the hydrophobic core or variations of hydrocarbon chain length, it is evident that in solution systems, the behavior of such molecules can be varied [4]. To understand the intermolecular interactions of SDS in CAD + E-OH mixtures, we determined several physicochemical characteristics. The prevailing molecular interactions and micelle growth at particular concentrations are interpreted using different techniques such as conductivity, surface tension, refractive index, Uv-Visible spectroscopy and fluorescence [5]. However, we use conductivity and spectroscopic methods in this study; SDS was chosen because it is widely known for its ability to create micellar solutions. SDS is amphiphilic and features a 12-carbon tail connected to the sulfate group. It is said to be more effective than urea and guanidine hydrochloride at denaturing proteins. Because of its high foaming properties, ease of accessibility, and low production cost, SDS is considered the best option. SDS has numerous biological functions, including antibacterial and skin cleaning effects [6]. It is well-documented that the interaction due to the presence of an oxygen group acts as both an acceptor and a donator [7]. In this work, SDS is chosen to quantify the impact of various solution environments on physical characteristics in the continued development of innovative drug delivery systems, including micellar solution. On the other hand, cinnaldehyde [CAD] is a liquid aldehyde derived from the bark of Cinnamomum trees, a naturally occurring flavonoid often used as a natural flavoring and fragrance agent in the kitchen and industry [8]. In addition, CAD is believed to have various beneficial properties, for instance antimicrobial [9], antioxidative [10], and inhibiting antiapoptotic [11] properties. CAD is found to protect against gram-positive/negative infection [1], diabetes [12], gastric ulcer [13], cardiomyopathy hypertrophy, [14] brain I/R injuries [15]. Cinnamaldehyde (CAD) is a representative substrate containing the carbonyl and vinyl groups simultaneously. It is worth mentioning, that the proposed work was designed to increase the solubility of hydrophobic CAD and to encapsulate the CAD molecules via micelles to offer protection against degradation. However, here we study the possible molecular interaction and micelle formation between CAD molecules in SDS ethanol mixed media. This study has further applications in drug delivery vehicles as an encapsulated micelle formulation, and is expected to improve cellular uptake with reduced side effects. However, the slight solubility of CAD in water restricts the study of interactions in aqueous media. Meanwhile, ethanol, a polar solvent self-associated through hydrogen bonding, is expected to interact strongly with other fluids by hydrogen-bonding, and was preferred in the present study. Thus, it would be interesting to make a comparison of the micellar properties of SDS in pure ethanol mixtures and in ethanol-CAD mixtures.