TECHNICAL FIELD

The invention relates to shape memory and self-healing hydrogel, comprising nanoparticles suitable for use in sensors, electronic organic materials, raw materials for 3D printers, obtaining nanosized biomaterials, implants for the human body, obtaining drug delivery systems or nanomedicine, lithium batteries, photovoltaic materials, and batteries.

The present invention is also for obtaining a new hydrogel for the related technical field. In addition, information is provided about the technical fields in which the hydrogel obtained in this invention can be used.

BACKGROUND

Smart materials are a class of materials whose chemical composition and physical condition vary; they have one or more physical (optical, magnetic, electrical, mechanical) or physicochemical (rheological) properties that can vary significantly with external factors (excitatory) such as pressure, temperature, humidity, pH, electrical or magnetic field. Examples of these smart materials include shape memory alloys (SMA), thermo-piezoelectric materials, photovoltaic materials, magnetic heavy materials, piezo materials, electrologic fluids, light emitting diodes, color-changing materials, and smart polymers and alloys. The mentioned smart materials can be used in the healthcare sector (orthodontic braces, stents, instruments used in the field of endodontics, orthopedic products), robotic technology, the automotive industry, damping elements, aviation and space studies, buildings, and infrastructure.

Shape memory polymeric materials are in the most commonly used materials group in the art and can exhibit shape memory properties in several ways. For example, gels that can swell and shrink with the effect of the magnetic field can be given.

The areas of use of polymers are increasing day by day. Today, there are many studies on smart polymers. The goal of these studies is to synthesize polymers that can change shape with an external effect and return to their original state when the effect disappears. These polymers, which can easily return to their permanent form when a certain temperature is exceeded, are primarily used in the biomedical field of research. It is especially preferred in different applications such as artificial skin, surgical sutures, and drug release. Smart biomaterials have a large use in drug transport (nanoparticle delivery to the target in the body) systems.

Since smart polymers are sensitive to pH or temperature, they can carry release of the drug substance they carry to the desired areas of the body, even in sensitive changes in the environment. Thus, they perform the tasks of releasing the drug substance they carry.

As a result, the said polymers can be used in many different technical fields thanks to their many features as smart materials.

In the patent application 2017/07087, the invention relates to a shape memory polymer, a production method thereof, a method for programming, and the use thereof. The shape memory polymer according to the invention has at least two switch segments with a different transition temperature (Ttrans T ans, 2), so that this polymer can take at least two temporary shapes (TFI, TF2) next to a permanent shape (PF) depending on the temperature. The first switch segment is based on a polyester according to the general formula (I), predominantly n= 1...6, or a co-polyester according to the general formula (I) with different n values, or a derivative thereof. The second switch segment is based on a polyether according to the general formula (II) or a co-polyether according to the general formula (II) with different m values, predominantly m = 1 ...4, or a derivative thereof.

The patent numbered EP2475408B1 relates to a drug container for a liquid drug. A drug container comprises an outlet and a shape-changeable bag having at least one shapechanging element consisting of a shape-memory alloy. At least one shape-changing element according to the invention is arranged to change the shape of the bag that can be squeezed out of the outlet of a dose drug bag when the shape memory alloy passes through a phase transition from a first stage to a second stage and thus changes the shape of the shapechanging element.

Patent numbered US6388043 B1 relates to shape memory polymer compositions, their manufacturing materials, and methods of preparation and use thereof. The shape memory polymer compositions can retain multiple shapes in the memory. Suitable compositions include at least one hard segment and at least one soft segment. The compositions may further comprise two soft segments coupled through light, electric field, magnetic field, or functional groups that are cleaved in response to ultrasound application. Splitting these groups will cause the object to return to its original shape.

Patent numbered WO2019193124 A1 relates to regulations of shape memory polymers. Accordingly, in the invention, shape memory polymers can be programmed to have a permanent (first) shape and a temporary (second) shape, and can substantially recover their original (first) shape by applying an appropriate stimulus.

The subject of the article "Polymers with Dual Light-Triggered Functions of Shape Memory and Healing Using Gold Nanoparticles" written by Zhang, H. et aL, is the photothermal effect induced by simple laser irradiation using the synergistic effect between Gold nanorod (AuNR) and vitrimer, and the shape memory effect of the vitrimer returns AuNR to its initial direction and provides self-healing in the cutting area. It has been shown that the optical properties of the polarizing film, such as the light transmittance and the degree of polarization, are fully recovered without an external repair agent.

The subject of the article titled " DNA-Based Hydrogels Loaded with Au Nanoparticles or Au Nanorods: Thermoresponsive Plasmonic Matrices for Shape-Memory, Self-Healing, Controlled Release, and Mechanical Applications" by Wang, C. et al. relates to the loading of plasmonic nanoparticles into polyacrylamide hydrogels cross-linked with bisacrylamide and nucleic acid duplexes or boronate ester-glucosamine and nucleic acid duplexes. Thanks to the thermo-plasmonic effect after the light stimulation of the gels, DNA duplexes were separated and hydrogels with lower hardness were obtained. In this way, reversible control over the hardness properties of hydrogels, shape memory hydrogels, and self-healing soft materials have been developed and used to adapt thermo-plasmonic interchangeable drug release.

The subject of the article entitled Multi-Field Synergy Manipulating Soft Polymeric Hydrogel Transformers by Zhang, D. et al. is related to the presence of gelatin in the hydrogel structure obtained by embedding FesC magnetic nanoparticles in a poly(N-(2-hydroxyethyl) acrylamide)-gelatin dual network structure, while providing shape memory and self-healing properties, while FesC nanoparticles provide both photothermal heating and magnetic manipulation functions. The fact that polymers are both economical and easy to process rapidly increases their consumption compared to other substances. Excessive polymer consumption is considered an indicator of the development of countries. However, modified materials are needed to reduce the increasing polymer waste today. At this stage, the studies carried out to restore self-recovery, repair, and even physical or mechanical wear and tear are increasing day by day. Hydrogels are modified to show SMP (Shape Memory Polymer) and SHP (Self Healing Polymer) properties. Today, it is predicted that the modification of hydrogels in all areas of our lives to show the characteristics of SMP and SHP will take place in an application that will contribute to the quality of life.

As a result, the said polymers are produced and used in many technical fields thanks to their various properties in the smart material group. In this invention, a new hydrogel with superior properties is obtained for the related technical field.

BRIEF DESCRIPTION OF THE INVENTION

The present invention provides for the introduction of a new product as an alternative to the information and products known in the state of the art. Thanks to the product mentioned in the invention, some of the partial disadvantages specified in the state of the art are eliminated. The main innovative aspect of the invention is to create a product with superior features for the relevant technical field and to contribute to the development of the product range.

In another aspect, the invention is for obtaining a polymer-based hydrogel having both self- healing and shape memory effects.

In another aspect, the invention is for obtaining a hydrogel having deformability and self- healing properties by containing components showing a photothermal effect due to surface plasmon resonance.

In the possible embodiment of the invention, smart materials with various properties can be obtained with the presence of various metal nanoparticles, drug-active or therapeutic components, sensors, or components of various nanoscale that can be added to the hydrogel structure to be obtained. In order to provide all these features, the invention is hydrogel suitable for use in sensors, electronic organic materials, as raw material for 3D printers, in obtaining nanosized biomaterials, obtaining implants, drug delivery systems or nanomedicines for the human body, in lithium batteries, photovoltaic materials, and batteries, characterized in that it comprises

• an acrylate polymer and vinyl pyrrolidone compounds comprising an alkyl group with a carbon number of Ce and above, capable of self-healing and exhibiting shape memory behavior with qualitative temperature variations, wherein the said temperature value is above the melting temperature of the components,

• the said hydrogel is heated by a light source at different wavelengths using the photothermal effect caused by the surface plasmon resonance and trapped therein, it comprises metals such as nanosized silver, gold, palladium, titanium, nickel and graphene and acceptable alloys thereof as the said nanoparticle.

In the possible embodiment of the invention, the methacrylate polymer is at least one of the compounds of stearyl methacrylate and/or octadecyl acrylate.

In the possible embodiment of the invention, the acrylate polymer is stearyl methacrylate.

In the possible embodiment of the invention, the said nanoparticle is in the form of a solid nanocube, nanowire, nanosphere and nanocage in the hydrogel material.

In the possible embodiment of the invention, the nanoparticle is nanosized gold and/or silver or combinations thereof.

In the possible embodiment of the invention, the nanoparticle is a mixture of silver with a nanocage geometric structure and gold with a nanocube structure.

In the possible embodiment of the invention, it comprises a hydrogel containing the compounds stearyl methacrylate and vinylpyrrolidone as components, and a nanoparticle trapped in the hydrogel, as well as at least one auxiliary component selected from the group of amines material, polyethylene, polypropylene, polystyrene, acceptable acrylates, vinyl chlorides, which can provide additional properties for the hydrogel. In the possible embodiment of the invention, the values of the wavelength are in the range of 430 nm to 700 nm.

In the possible embodiment of the invention, the vinyl pyrrolidone component is in the range of 10% to 90% by weight in the hydrogel.

In the possible embodiment of the invention, the stearyl methacrylate is in the range of 10% to 90% by weight in the hydrogel.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the subject of the invention is related to a hydrogel with shape memory effect and self-healing properties, which is suitable for use in different functions in various technical fields thanks to these features and is explained with examples that do not have any limiting effect only for a better understanding of the subject.

The smart material with the features described in the invention is polymer-based. This polymer material has a hydrogel structure. In the invention, "hydrogel" refers to waterinsoluble cross-linked hydrophilic polymers.

In the main embodiment of the invention, the hydrogel material comprises at least two components. These two components are an acrylate-based polymer, one of which contains an alkyl group with a length of Ce and above.

The said acrylate-based polymer comprises at least one of the compounds stearyl methacrylate and the compound octadecyl acrylate.

Most particularly, the acrylate-based polymer is the stearyl methacrylate compound. In the invention, the CAS number of the stearyl methacrylate compound is 32360-05-7, and its formula is H ₂ C=C(CH3)CO2(CH ₂ )i7CH3.

Another component of the hydrogel material of the invention is the vinylpyrrolidone compound. The CAS number of the said compound is 88-12-0 and its formula is CeHgNO. The vinyl pyrrolidone compound contains hydrogen bonds; it has biocompatible and adhesive properties. The preferred embodiment of the invention is obtaining a hydrogel in which these compounds are used as monomers. However, compounds such as polyethylene, polypropylene, polystyrene, acceptable acrylates, vinyl chlorides, amides, and amines can be added to the hydrogel to be obtained to provide additional properties according to the field of use.

In the invention, "mass polymerization" is referred to as polymerization processes carried out in environments where monomers (components to be used) are directly or in which additives such as an initiator and chain transfer agents are present.

The method used in the invention to obtain hydrogel from components is a mass polymerization method.

The hydrogel material obtained by mass polymerization has qualitatively self-healing and shape memory properties with temperature changes. The said temperature value is the value above the melting temperatures of the components contained in the hydrogel. If the stearyl methacrylate compound is used as a component in the production of hydrogel, the temperature value is 24°C.

This hydrogel material contains at least one nanoparticle. The nanoparticle may be a nanosized metal particle, a drug nanoparticle, or a nanosized sensor. Hydrogel material for nanoparticles may act as a membrane or tank, or both.

The nanoparticle may also be dispersed within the hydrogel material or may also be present as a nanosized solid material.

Here, nanosized metal particles are preferred as nanoparticles. Metals such as silver, gold, palladium, titanium, nickel, and acceptable alloys can be used as the said metal particles. The hydrogel-metal nanoparticle system to be produced as smart material may vary depending on the technical field to be used.

The hydrogel of the invention comprises nanoparticles of at least one metal or acceptable alloy with a photothermal effect due to surface plasmon resonance. The hydrogel, which contains nanosized metal particles with this property, creates reactions for light at various wavelengths. The nanoparticle referred to herein is at least one of the gold nanosphere, silver nanocube, and gold nanocage structures. The wavelengths vary according to the added nanoparticle component and are expected to act preferably in the range of 430 nm to 700 nm.

The invention uses nanosized silver and/or gold elements and/or acceptable alloys as nanoparticles.

The preferred nanoparticle is silver and/or its acceptable alloys.

The preferred nanoparticle is gold and/or its acceptable alloys.

The preferred nanoparticle comprises mixtures of gold and silver in certain proportions by weight.

One of the innovative aspects of the invention is that the geometric structures of nanosized materials to be used as nanoparticles are in the form of nanocube and/or nanocage. In the invention, thanks to the nanocube and/or nanocage of the nanostructures, the double surface area of these structures has a much better efficiency at the photothermal energy point compared to the nanoparticles in other nanoparticle structures with the high light scattering associated with their edges and the synergistic effects of the lightning rod structure.

The nanoparticle preferred in the invention is gold and/or acceptable gold alloys having a nanocage structure.

The nanoparticle preferred in the invention is silver and/or acceptable silver alloys having a nanocube structure.

The smart material of the invention can be obtained with the following options;

1 ) a hydrogel, the nanoparticle of which is gold and/or acceptable gold alloy in the nanocage structure and which trapped this nanoparticle and comprises the compounds stearyl methacrylate and vinylpyrrolidone as components,

2) a hydrogel, the nanoparticle of which is silver and/or acceptable silver alloy in the nanocage structure and which trapped this nanoparticle and comprises the compounds stearyl methacrylate and vinylpyrrolidone as components, 3) a hydrogel, the nanoparticle of which is gold and/or acceptable gold alloy in the nanocube structure and which trapped this nanoparticle and comprises the compounds stearyl methacrylate and vinylpyrrolidone as components,

4) a hydrogel, the nanoparticle of which is silver and/or acceptable silver alloy in the nanocube structure and which trapped this nanoparticle and comprises the compounds stearyl methacrylate and vinylpyrrolidone as components,

5) a hydrogel, the nanoparticle of which is gold in the nanocage structure and silver in the nanocube structure and which trapped this nanoparticle and comprises the compounds stearyl methacrylate and vinylpyrrolidone as components.

The hydrogel may also be referred to as the matrix in the invention. In the aforementioned options, the nanoparticle trapped in the matrix and a coating and capsule surrounding this matrix may also be the subject of the invention. Although the innovative aspect of the invention is clear, it is evident by the person skilled in the art that each ingredient to be added, which contains stearyl methacrylate and vinylpyrrolidone compounds, which are the main components in obtaining hydrogel, and which increase the performance of these compounds, will remain within the scope of the protection of the invention.

Hydrogel materials can be initiated with a suitable stimulus in all systems, such as the shape memory effect, the temperature at the appropriate values, the light source at the appropriate wavelengths, or combinations thereof.

Although the innovative aspect of the invention is the hydrogel containing the compounds stearyl methacrylate and vinylpyrrolidone, the use of a nanoparticle that can create a synergistic effect with this hydrogel material is important for the invention. In this invention, nanoparticles are used in a wide range of applications. It is known that hydrogels are widely used in the technical field. The hydrogel thus obtained can be used in many different functions in many technical fields. However, in the invention, the nanoparticle is mainly gold and silver or acceptable alloys thereof or combinations thereof in nanocage and/or nanocube structures, the use of such nanoparticles provides a photothermal effect due to surface plasmon resonance, enabling the smart material to have light-repairing and deformation properties. As can be seen, the use of such a nanoparticle provides additional properties to the hydrogel material of the invention. The smart material obtained in the invention consists mainly of two structures containing a hydrogel network system and nanoparticles, but it can also be shaped in accordance with the field of use. The possible embodiment of the invention may thus comprise a smart material comprising the hydrogel network system and nanoparticles, at least one therapeutic drug substance for the treatment of various diseases. A smart material comprising hydrogels and nanoparticles may comprise bio-sensors, electric-electronic sensors, capacitors, or energy storage components.

The scope of protection of the invention is specified in the attached claims and cannot be limited to those explained for sampling purposes in this detailed description. It is evident that a person skilled in the art may exhibit similar embodiments in light of the above-mentioned facts without drifting apart from the main theme of the invention.