Super absorbent polymer

1 . A polyacrylic acid (salt)-based super absorbent polymer, comprising:

carbon, oxygen, and sodium on the surface thereof; and

the super absorbent polymer satisfies Equation 1 below:

X C═O +X O—C═O ≥6(at %)  [Equation 1]

wherein,

X C═O represents a content (at %) of carbon included in a C═O bond structure among all elements present on the surface of the super absorbent polymer according to XPS analysis, and

X O—C═O represents a content (at %) of carbon included in a O—C═O bond structure among all elements present on the surface of the super absorbent polymer according to XPS analysis,

wherein the super absorbent polymer satisfies Equation 2 below:

X C═O +X O—C═O ≤15(at %)  [Equation 2]

2 . The super absorbent polymer of claim 1 , wherein the super absorbent polymer satisfies Equation 3 below:

X C═O ≥ XO—C═O   [Equation 3].

3 . The super absorbent polymer of claim 1 , wherein the X O—C═O is 2.5 at % or greater.

4 . The super absorbent polymer of claim 1 , wherein the X C═O is 3.5 at % or greater.

5 . The super absorbent polymer of claim 1 , wherein the super absorbent polymer satisfies Equation 4 below:

(X O—C═O /X C )×100(%)≤10(%)  [Equation 4]

wherein,

X C represents a total content (at %) of carbon among all elements present on the surface of the super absorbent polymer according to XPS analysis.

6 . The super absorbent polymer of claim 1 , wherein a content (X o ) of an oxygen element with respect to all elements present on the surface of the super absorbent polymer according to XPS analysis is 50 at % or less.

7 . The super absorbent polymer of claim 1 , wherein a content (X Na ) of a sodium element with respect to all elements present on the surface of the super absorbent polymer according to XPS analysis is 6 at % or less.

8 . The super absorbent polymer of claim 1 , wherein a content (X Si ) of a silicon element with respect to all elements present on the surface of the super absorbent polymer according to XPS analysis is 15 at % or less.

9 . The super absorbent polymer of claim 1 , wherein the super absorbent polymer satisfies Equation 6 below:

X C═O +X O—C═O >X Na   [Equation 6]

wherein,

X Na represents a content (at %) of sodium among all elements present on the surface of the super absorbent polymer according to XPS analysis.

10 . The super absorbent polymer of claim 1 , wherein the super absorbent polymer comprises one or more elements selected from the group consisting of silicon, nitrogen, aluminum, and sulfur on the surface of the super absorbent polymer.

11 . The super absorbent polymer of claim 1 , wherein when the super absorbent polymer is swollen for 1 minute with water having an electrical conductivity value of 100 μS/cm to 130 μS/cm, a free swell capacity of water containable by the super absorbent polymer is 130 g/g or greater.

12 . A polyacrylic acid (salt)-based super absorbent polymer, comprising:

carbon, oxygen, and sodium on the surface thereof; and

the super absorbent polymer satisfies Equation 1 below:

X C═O +X O—C═O ≥6(at %)  [Equation 1]

wherein,

X C═O represents a content (at %) of carbon included in a C═O bond structure among all elements present on the surface of the super absorbent polymer according to XPS analysis, and

X O—C═O represents a content (at %) of carbon included in a O—C═O bond structure among all elements present on the surface of the super absorbent polymer according to XPS analysis,

wherein the super absorbent polymer satisfies Equation 4 below:

(X O—C═O /X C )×100(%)≤10(%)  [Equation 4]

wherein,

X C represents a total content (at %) of carbon among all elements present on the surface of the super absorbent polymer according to XPS analysis.